research article power quality investigation of...

Research ArticlePower Quality Investigation of Distribution NetworksEmbedded Wind Turbines

A Elsherif T Fetouh and H Shaaban

Electrical Engineering Department Faculty of Engineering Menoufia University Shebin El Kom 32511 Egypt

Correspondence should be addressed to A Elsherif amelsherifsh-engmenofiaedueg

Received 4 January 2016 Accepted 13 March 2016

Academic Editor Ujjwal K Saha

Copyright copy 2016 A Elsherif et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

In recent years a multitude of events have created a new environment for the electric power infrastructure The presence of small-scale generation near load spots is becoming common especially with the advent of renewable energy sources such as wind powerenergyThis type of generation is known as distributed generation (DG)The expansion of the distributed generators- (DGs-) basedwind energy raises constraints on the distribution networks operation and power quality issues voltage sag voltage swell voltageinterruption harmonic contents flickering frequency deviation unbalance and so forth Consequently the public distributionnetwork conception and connection studies evolve in order to keep the distribution system operating in optimal conditions In thispaper a comprehensive power quality investigation of a distribution system with embedded wind turbines has been carried outThis investigation is carried out in a comparison aspect between the conventional synchronous generators as DGs are widely inuse at present and the different wind turbines technologies which represent the foresightedness of the DGs The obtained resultsare discussed with the IEC 61400-21 standard for testing and assessing power quality characteristics of grid-connected wind energyand the IEEE 1547-2003 standard for interconnecting distributed resources with electric power systems

1 Introduction

Nowadays power quality (PQ) in the distribution systemshas been a research area of exponentially increasing interestbecause of an increasing concern to both distribution utilitiesand customers The increased concern of power qualityhas resulted in measuring power quality variations andcharacteristic disturbances for different customer categoriesLoad switching system faultsmotor starting load variationsnonlinear loads intermittent loads and arc furnaces usuallycause power quality disturbancesThese causemany electricaldisturbances such as voltage sag swell harmonic distortionsinterruptions flicker and unbalance Power quality assess-ment is very important for operation of devices in customerside and its issue is also important for the utility companiesthat are obliged to supply consumers with electrical power ofacceptable quality [1ndash5]

Wind power turbines have nowadays increasing pen-etration levels in power grids for their splendid reserveThe wind turbine can be connected to either a high volt-age network as a wind farm or distribution systems as

individual turbines Such power turbines have their owncharacteristics and operation modes Consequently severalchallenges arise concerning their impacts on the powersystem profile regarding the power quality issues [6 7]

Considering the frequent occurrence of power qualityproblems in the distribution system in addition to the newtrend for using wind turbines as new distributed genera-tors (DGs) the power quality analysis of the distributionsystem considering different technologies of wind turbinesbecomes imperatively important Therefore in this paper acomprehensive study of the power quality problems for aconsidered 15-bus radial distribution system with embeddeddistributed generators (DGs) has been carried out Differenttechnologies of the DGs have been considered The powerquality studies are carried out in a comparison aspect betweenthe conventional synchronous generator asDGs arewidely inuse at present and the different wind turbines technologieswhich represent the foresightedness of the DGs The absenceof DGs is assumed as a base case for the studies

This paper is organized as follows Section 2 describesthe considered distribution system component modelling

Hindawi Publishing CorporationJournal of Wind EnergyVolume 2016 Article ID 7820825 17 pageshttpdxdoiorg10115520167820825

2 Journal of Wind Energy

Bus 1 Bus 2 Bus 3 Bus 14 Bus 15

Load 2 Load 14Load 3Load 15T1

DG

T2

Substation

Bus 4

Load 4

66 kV

Bus 575 V

Z14-15Z1 2- Z2 3- Z3 4- middot middot middot

Figure 1 Single line diagram of the considered 15-bus distribution system

+

V

+

++

+

5

UPF control mode

Voltage control mode

Voltage regulator

Var regulator

Qm

Qref = 0minus

minus

minus

Vref

K = 02

Vref = 1

Efdo

KA = 100 TA = 001 minus5

Efd

KTs

Z minus 1

KA

1 + TAS

Figure 2 IEEE type-AC1A excitation system

The steady state voltage profile of the considered system isgiven in Section 3 Section 4 presents a complete study aboutvoltage sag voltage swell and voltage interruption duringload variation and system disturbances Voltage fluctuationand flicker resulting fromwind speed variation and pulsatingloads are analyzed in Section 5 The harmonic distortionsupplied by the wind turbine generators and the nonlinearloads are investigated in Section 6 Section 7 discusses theelectrical power losses and the effect of wind turbine outputpower and connection point on power loss values FinallySection 8 summarizes the main conclusions

2 Configuration of the ConsideredDistribution System

In this paper the 15-bus radial distribution system shown inFigure 1 is considered All the system data are given in theAppendix Each of the feeder sections is represented by seriesRL impedance and the system transformers are modelledby its T-equivalent circuit In the steady state studies theloads are represented by constant power models as is usualin the load flow studies while in the dynamic studies theloads are represented by constant impedanceThe simulationpackage adopted is the Sim-Power Systems for use withMatlabSimulink

The DGs considered in this paper are the conventionalsynchronous generators which arewidely in use at present inaddition to the wind turbine generators which represent theforesightedness of the DGsThewind turbines generators canbe classified as fixed speed and variable speed wind turbinesgenerators The fixed speed induction generator (FSIG) windturbine is equipped with a squirrel-cage induction generatorwhile the variable speed wind turbines can be either a par-tially rated converter- or a fully rated converter-based wind

turbine The partially rated converter-based wind turbinesare always equipped with a double fed induction generator(DFIG) The fully rated converter-based wind turbine canbe equipped with a wound rotor induction generator or aconventional synchronous generator or a permanent mag-net synchronous generator (PMSG) The PMSG is the onecommonly used for avoiding the field current supply neededby wound rotor synchronous generators or because of thereactive power compensation facilities needed by inductiongenerators Furthermore the PMSG removes the need for sliprings

The following subsections summarize themodelling of allthe considered distributed generators

21 Synchronous Generators In this paper the synchronousgenerator is represented by the eight-order model [8] Thereare two different modes of controlling the generator exci-tation system One aims to maintain its terminal voltage(constant voltage control mode) while the other one aimsto maintain its power factor (constant power factor controlmode) [9] The power factor control mode is usually adoptedby independent producers to maximize the active powerproductionThe set points of voltage control and unity powerfactor control mode are depicted in Figure 2

22 FSIG Wind Turbine Figure 3 shows the schematic dia-gram of a fixed speed wind turbine which consists of threemain parts the rotor the drive train and the squirrel-cageinduction generator (SCIG) The dynamic models of therotor and the drive train are given in [10] The SCIG wasrepresented by the fourth-order state-space model and itsmechanical parts were represented by a second-order system[8]The generator needed reactive power was locally supplied

Journal of Wind Energy 3

GridSCIG

Rotor Drive train Generator

GB

Capacitor

Figure 3 Schematic diagram of the FSIG

DFIGGB

NSCRSC

Back-to-back PWM converter

RSC control GSC control

Stator current

RotorP Q QUdc

current

Figure 4 Configuration of the DFIG wind turbine

by capacitors installed at its terminalsThe capacitor capacitywas adopted equal to 13 of the generator rated power [11]

23 DFIG Wind Turbine The basic configuration of theDFIG driven by wind turbine is shown in Figure 4TheDFIGis a wound rotor induction generator which has the samemodel of SCIG except that the rotor voltage does not equalzero [12]

The DFIG is fed from its both stator and rotor sides Thestator is directly connected to the grid while its rotor is con-nected to the grid through a variable frequency ACDCACconverter (VFC) The VFC consists of two four-quadrantinsulated-gate bipolar transistor (IGBT) pulse width modu-lation (PWM) converters connected back-to-back by a DC-link capacitor [13 14]

In order to deliver an electrical power with constantvoltage and frequency to the utility grid for a wide operatingrange of speed from subsynchronous to supersynchronousspeeds the power flow between the generator rotor circuitand the grid must be controlled in both magnitude anddirection Connecting the rotor with the grid via a four-quadrant AC-to-AC converter enables the decoupling of thecontrol of the generator active and reactive powers Also thevariable frequency rotor voltage permits the adjustment ofthe rotor speed to match the optimum operating point at anypractical wind speed

DFIG +minus

PWMPIPI

PIPI

+minus

++

++minusminus

minusminus

minus minus

minus

++

Network

calculation

PIPI

PIPI

++

++

++ +

+

NSC

RSC

PWM

calculation

++minus

minus

Vdc Idg

Iqg

Vdg1

Vs

Qg

Vdg

Vqg

120596sLgiqg

120596sLgidg

Qgs

Ps and Qs

Ps

Qs

Iqr

Idr

minusRridr + (Lm + Lr)iqr + Lmiqr

Vqr

Vqr1

Vdr

Vdr1

minus(Lm + Lr)idr minus Lmidr

Vlowastdc

Qlowastg

Ilowastdg

Ilowastqg

Plowasts

Qlowasts

Ilowastqr

Ilowastdr

Figure 5 Basic control loops for the RSC and NSC

The rotor side converter (RSC) and the network sideconverter (NSC) control circuits are shown in Figure 5 wherethe RSC control system consists of two basic control loopsfor the active and the reactive powers 119875 and 119876 respectivelyThe NSC is used for keeping the DC-link capacitor voltageconstant regardless of the magnitude and direction of rotorpower as well as controlling the NSC output reactive powerespecially in case of the grid disturbance

The constant power factor and constant voltage controlmodes previously described in the synchronous generatorsubsection will be considered with the DFIG The constantpower factor control mode can be adjusted by setting 119876lowast

119904

stator reference reactive power and 119876lowast119892 NSC reference

reactive power to zero On the other side the voltagecontrolmode can be obtained by adjusting the reactive powerreference to obtain a generator terminal voltage of 1 pu

24 PMSG Wind Turbine The typical configuration of thefully rated converter- (FRC-) based wind turbine is shown inFigure 6As all the power from thewind turbine is transferredthrough the power converter the specific characteristics anddynamics of the wind turbine generator are completely iso-lated from the power networkHence the electrical frequencyof the generator may vary as the wind speed changes whilethe network frequency remains constant permitting thegenerator variable speed operation Note that rating of the


PM synchronous

generator PWM-VSC

GB

Dioderectifier Booster

Network

Generatorcontrol

DC-linkvoltage control

Figure 6 Typical configuration of the FRC-based wind turbine

power converter for this wind turbine type is usually morethan the generator rated power [14]

Figure 6 shows the arrangement of the PMSG with anuncontrolled diode-based rectifier as the generator side con-verter (GSC) DCDC converter (DC booster) and voltagesource converter (NSC) as power electronics controlledconverters

Below rated wind speed the control objective is to trackwind speed to capture and transfer the maximum power tothe grid The generator and rectifier system is uncontrolledTherefore the control has to be implemented by the powerelectronics converters DCDC converter (DC booster) andvoltage source converter (NSC) [14]

DCDC converters regulate the DC voltages of generator-rectifier units by varying the switching ratio so that theoptimum DC voltage profile is presented at the rectifierterminal for maximum power capture operation Meanwhilean appropriate DC voltage is maintained at the DC bus toenable the voltage source inverters to perform the optimalreal power transfer and reactive power regulation A blockdiagram of the vector control of the network side converterand DC booster is shown in Figure 7

3 Steady State Voltage Profile Computations

Before installing new DGs utility engineers must analyzethe distributor worst operating scenarios to study how thevoltages at the connected loads terminals are affected bythe installed DGs These scenarios are characterized by thefollowing [15]

(i) no generation and maximum load demand(ii) maximum generation and maximum load demand(iii) maximum generation and minimum load demand

In this paper it is considered that the minimum loaddemand corresponds to 10 of the maximum demand andthe allowable steady state voltage regulation is equal to plusmn5of the supply voltage

It is important to note that considering the case withoutDG the substation transformer tapping was adjusted tomaintain the voltage values at all the feeder buses within theallowable range for minimum and maximum demands

Now to determine the steady state voltage profile ofthe considered distribution system with the considered DG

PMSG+Network

PIPI

PIPI

+++

++

+

NSC network side converter

PWM

calculation

PIPI +

+IL

Speed regulator Current regulator

PWM

DR diode rectifier

DRNSC

Vlowastdc

BC boost converter

BC

Vdc IdNVdN

VdN

VdN1

QN

QN

IqN

VqN1 VqN

120596sLgiqg minus idgRg

VqN minus 120596sLgidg minus idgRg

120596r

minus

minus

minus

minusminus

minus

minus

minus

minus

minus

QlowastN

IlowastdN

IlowastqN

120596lowastref

ILlowastref

Figure 7 Basic control loops for the NSC and DC booster

types it is assumed that a 2MW (about 30 of the distributortotal maximum load demand) DG is connected at bus 15(see Figure 1) Considering each of the previously discussedDG types the voltage at each of the distributor buses isdetermined and the results are depicted in Figure 8 Referringto Figure 8 the following can be seen

(i) Some buses voltages will violate the superior limitduring minimum demand when the unity powerfactor (UPF) operating mode is considered for syn-chronous generator DFIG and PMSG

(ii) The performance of FSIG is very close to without DGcase some buses voltages will be below the inferiorlimit during maximum load demand and above thesuperior limit during minimum load demand

(iii) If voltage control mode (119881119862) for synchronous gen-

erator DFIG and PMSG is employed then thesteady state buses voltages will remain within theallowable range for both maximum and minimumload demands

31 Steady State Voltage Variation due to DG DisconnectionOne important issue related to the distributor steady statevoltage profile is to determine how much the load busesvoltages will change when the DGs are disconnected becausethe actuation time of voltage controllers in distributionsystems for example under load tap change transformers isslow Thus network operators want such variations to be assmall as possible In order to analyze this issue the following


(3)

(6)

(2)(1)

(7)(5)

(8)

(4)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus number

095096

098

1

102

104105

Bus v

olta

ge (p

u)

(1) No DG(2) FSIG(3) DFIG (UPF)

(5) PMSG (UPF)

(7) Synch (UPF)(8) Synch (VC)

(6) PMSG (VC)

(4) DFIG (VC)

(a) Maximum demand (100)

(2)

(7)

(8)

(6)

(4)

(1)

(3)

(5)

1011015

1021025

1031035

1041045

1051055

106

Bus v

olta

ge (p

u)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus number

(1)(2)(3)(4)

(5)(6)(7)(8)

(b) Minimum demand (10)

Figure 8 Steady state voltage profile of the distributor buses for different DG types

Table 1 Steady state voltage variation (VI) due to DG disconnec-tion

Generator type VIMaximum load Minimum load

FSIG 0043 0642DFIG

UPF 1089 0743Voltage control 2276 1368

PMSGUPF 1088 0744Voltage control 2250 1343

SynchronousUPF 1091 0746Voltage control 2247 1301

global index can be utilized to quantify the impact provokedby a generator disconnection [16]

VI =sum119899119887

119894=1

1003817100381710038171003817119881119892

119894minus 119881119899

119894

1003817100381710038171003817 times 100

sum119899119887

119894=1119881119899

119894

(1)

where 119899119887is the total number of the distributor load buses

119881119892

119894is the magnitude of the load voltage at bus 119894 with the

connected DGs and 119881119899119894is the bus voltage without DGs

Assuming that the distributor DG connected to bus15 (see Figure 1) is removed the values of the factor VIare computed considering the distributor maximum andminimum loading conditions The obtained results are givenin Table 1 from which the following are clear

(i) Greater values of VI are obtained when each of theDFIG PMSG and synchronous generators is operat-ing under voltage control condition This essentiallymeans that using one of these DG types values of theload buses voltage will be adversely affected after thegenerator disconnection

(ii) Under the distributor maximum loading conditionthe loads buses voltage variation will not be greatly

(1)(2)

(3)(5) (7)

(8)

(4)

(6)095

0955096

0965097

0975098

0985099

09951

Volta

ge o

f bus

15

(pu)

02 04 06 08 1 12 14 16 180Load active power (MW)


(5) PMSG (UPF)


(6) PMSG (VC)

(4) DFIG (VC)

Figure 9 The 119875119871-119881119871characteristics of load connected to bus 15

assuming the admissible voltage range plusmn5

affected after the DG disconnection This means thatthe penetration ratio increase of theDGwill adverselyaffect the buses voltage after DG disconnection

32 The Distribution System 119875119871-119881119871Characteristics considering

Different DGs Types Normally it is expected that installationof the generators close to the loads can improve the systemvoltage stability However the impact on the voltage stabilitydepends on the reactive power exchange between the con-nected generator and the network which is different fromdistinct DGs technologies

In this section the 119875119871-119881119871characteristics of the system

shown in Figure 1 are analyzed by varying the load powerconnected to bus 15 keeping its power factor constant andassuming each of the DG types is connected to bus 15 with 2MW output power The 119875

119871-119881119871characteristics are computed

until the steady state admissible voltage limit plusmn5 and theobtained results are depicted in Figure 9 From the obtainedresults the following can be verified


Table 2 Maximum allowable penetration ratio of the DGs units considering steady state voltage violation

Generator type Number of units Results comments

FSIG Larger than 3 units The min admissible voltage regulation value is violated for maxloading condition

DFIG PMSG and Synch with voltagecontrol mode

6 units No admissible voltage violation for either max or min loadingconditions

DFIG PMSG and Synch with UPF mode 1 unit The max admissible voltage regulation value is violated for minloading condition

(i) The usage of the DGs independent of the typeincreases the load power margin while maintainingthe bus voltage within the admissible limits

(ii) The usage of the voltage control mode with DFIG orPMSG or synchronous generator leads to the largestpower transfer because these machines provide activeand reactive power to local loads

33 Effects of the DGs Penetration Ratios andTheir ConnectionPoints on the Considered Distributor Steady State Voltages Inthis section it is required to investigate the penetration ratioand connection point of different DGs technologies on theconsidered distribution system steady state voltage Firstlythe penetration ratios effect is illustrated by assuming that anumber of DGs units each of 2MW (30 of the distributortotal maximum load value) are connected through one-by-one basis at the distributor far end bus 15 see Figure 1For each assumed number of the connected DGs unitsthe buses voltages are determined considering only one ofthe considered DG four types The obtained results aresummarized in Table 2 from which the following are clear

(i) The considered distributor buses voltage regulationdoes not violate their admissible values (plusmn5) foreitherminimumormaximum loading only when theconnected DFIG or PMSG or synchronous generatoris operating with the voltage control mode Thepenetration ratio can reach twice the distributor load-ing without voltage violation but conductor currentrating limit will be the constraint

(ii) Connecting only one of the DFIGs or PMSGs or syn-chronous generators with the UPF operating modethe voltage regulation values at somebuseswill exceedits maximum admissible value for minimum loadingconditions For maximum loading condition thenumber of units can reach 5 units without voltageviolation

(iii) The utilization of local reactive power compensationwith the FSIG increases the FSIG penetration ratio tothree units without voltage violation

Now the connection point effect of the DGs on thedistribution system load voltages is illustrated in Table 3The FSIG voltage control operating mode considered withDFIG which is similar to that with PMSG and synchronousgenerator and UPF operating mode with PMSG which issimilar to that with DFIG and synchronous generator are

considered in this section Also the DG connection pointsselected are buses 3 5 7 9 11 13 and 15 At each connectionpoint different penetration ratios are considered (number ofDG units equal to 1 or 2 or 3 or 4) with maximum loadingcondition only From the obtained results the following canbe concluded

(i) For all cases the connection of the DGs despite thetype near the substation leads to the largest voltagereduction at the far end buses of the distributionsystem for all penetration ratios For this connectionpoint the voltage violates the minimum admissiblevalue (minus5) in italic font filled cell in Table 3

(ii) The best DG connection point for improving thesteady state voltage profile is found to be close to thefar end of the considered distribution system

(iii) At each connection point the DGs penetration ratioshave a little effect on the steady state voltage profile

(iv) The high penetration ratios of the FSIG connectedat the end of the distribution system lead to voltageviolation

(v) Also for large penetration ratios the UPF operat-ing mode will lead to voltage violation (this doesnot appear in Table 3) similar to that mentioned inTable 2

4 Short Duration Voltage Variations Profile

The short duration voltage variation can be defined as achange of the rms voltage value at the power frequencyfor a duration from 05 cycles to 1min [17 18] The voltagevariations are classified into three types as follows

(i) The voltage swell when the voltage value varies from110 pu to 180 pu

(ii) The voltage sag when the voltage value varies from010 pu to 090 pu

(iii) The voltage interruption when the voltage valuedecreases to less than 010 pu

The incidences of short duration voltage variations indistribution networks are relatively frequent During shortcircuits connection of a large load and disconnection oflarge capacitor voltage sags may occur at the system busesOn the other hand the single line to ground faults ordisconnection of large loads or connection of large capacitors


Table 3 DGs connection point and penetration ratio effect on the distribution system steady state voltages

DG PCC Number of DG units FSIG 119881119862with DFIG UPF with PMSG

119881min At bus 119881min At bus 119881min At bus

Bus 3

1 0948 15 0947 15 0949 152 0950 15 0948 15 0953 153 0952 15 0948 15 0956 154 0954 15 0948 15 0959 15

Bus 5

1 0951 15 0961 15 0954 152 0955 15 0968 15 0961 153 0959 15 0971 15 0968 154 0962 15 0973 15 0973 15

Bus 7

1 0951 15 0966 15 0955 152 0956 15 0973 15 0963 153 0960 15 0977 15 0971 154 0963 15 0979 15 0977 15

Bus 9

1 0952 15 0970 15 0957 152 0959 15 0979 15 0966 153 0962 15 0983 15 0975 154 0965 15 0985 15 0982 15

Bus 11

1 0953 15 0975 15 0959 152 0960 15 0984 15 0970 153 0964 15 0988 15 0979 154 0966 15 0990 15 0987 15

Bus 13

1 0954 15 0979 15 0961 152 0961 15 0987 13 0973 153 0965 15 0989 12 0982 104 0965 15 0989 12 0986 9

Bus 15

1 0955 14 0977 11 0962 132 0959 13 0981 11 0972 123 0959 13 0982 10 0977 114 0948 13 0979 10 0978 10

may lead to voltage swells Interruptions can be the resultof power system faults equipment failures intermittentloose connections in power wiring and control malfunc-tions

The presence of DGs may influence the magnitude andthe duration of the voltage sags swells and interruptions Itwill depend on the impact of these generators on the systemshort-circuit level and the dynamic behaviour of the reactivepower exchange between the generator and the network Inthis section the DGs performance during voltage sag swelland interruption is studied

41 Voltage Sag Magnitude and Duration due to Large Induc-tive LoadConnection In this subsection the behaviour of thedifferent DGs types during a large induction motor startingis studied An inductionmotor is assumed to be connected tobus 13 of the considered distributor and each of the previouslymentioned DGs types is assumed to be connected to bus 15

The results are obtained in Figure 10 from which thefollowing are clear

(1)(2)

(3)

(4)

(5)

(6)

07

075

08

085

09

095

1

Volta

ge o

f bus

13

(pu)

10 12 14 16 18 20 22 248Time (sec)

(1) No DG(2) FSIG

(6) Synch (UPF)(5) Synch (VC)(4) PMSG (VC)

(3) DFIG (VC)

Figure 10 Performance of different DGs due to induction motorstarting at bus 13 while the DG is connected at bus 15

(i) The voltage control operation mode of the DFIGPMSG wind turbine and synchronous generator canreduce the voltage sag magnitude and duration


Table 4 Effect of DG connection point on the voltage sag magni-tude and duration at bus 15

Connection bus ofDG

FSIG DFIG PMSG Synch119881119862

UPF

Minimum voltage sag (071 pu without DG)15 0713 0746 0729 0767 0746

13 0713 0739 0724 0753 0734

11 0714 0735 0723 0746 0729

9 0715 0731 0722 0739 0725

Voltage sag duration (966 sec without DG)15 895 695 795 696 866

13 904 729 822 732 878

11 908 748 836 747 881

9 914 769 851 766 888

(ii) Although the unity power factor operation mode(used with synchronous generator in this case) doesnot exchange reactive powerwith distribution systemthe voltage profile is better thanwithoutDG and FSIGcases

Now it is required to determine the effect of the DGconnection point on the voltage sag magnitude and durationTherefore it is assumed that each of the considered DGs (of2MW output power) is connected to buses 15 13 11 and 9while the induction motor is still connected to bus 13 Theminimumvoltage value and the voltage sag duration atwhichthe bus voltage is less than 09 pu of bus 15 are listed inTable 4 From the obtained results the following are found

(i) The utilization of DGs despite the type and locationreduces the voltage sag problem

(ii) The DG connection point affects the voltage sagmagnitude and duration

(iii) The connection of the DGs downstream inductiveload connection point enhances the system voltage(magnitude and sag duration) versus upstream con-nection except the voltage magnitude when the FSIGis utilized

(iv) The voltage control operating mode presents the bestperformance followed by unity power factor (usedwith synchronous generator in this case) and finallythe FSIG

42 DGs Types Effect on the Distributor Voltage InterruptionBecause most faults on distribution system are transientthe power can be successfully restored within several cyclesafter the current interruption Thus most automatic circuitbreakers are designed to reclose 2 or 3 times if neededin rapid succession The multiple operations are designedto permit various sectionalizing schemes to operate andto give some more persistent transient faults a secondchance to clear There are special circuit breakers for utility

Reclose interval1-2 sec

Figure 11 1-fast 3-delayed recloser scheme

distribution systems called ldquoreclosersrdquo that were designedto perform the fault interruption and reclose functionparticularly well

The isolated area from recloser operation is subjected tovoltage interruption The duration of voltage interruptionsdepends on the recloser operation characteristics Figure 11shows the common reclosing sequences used inmany utilitieswhich represent 1-fast 3-delayed operation [18 19] In case oftemporary faults which frequently occurred in distributionsystem as a SLG fault a voltage sag and swell will occur fora duration of 3 to 6 cycles followed by three-phase voltageinterruption After the elapsing of 1 to 2 sec from the voltageinterruption occurrence the reclosing process returns theisolated area to the main distribution system

The presence of DGs in the isolated area may affect thearea voltage interruption depending on the DG capability ofsupplying active and reactive power

In this section the response of each of the consideredDGs when a SLG fault occurs at a point on the distributoris studied considering the reclosing operation A SLG fault isassumed to occur at the time 05 sec at a point close to bus 8when the DG of 2MW is connected to bus 15 The assumedfault is removed after the elapsing of 016 sec (ie 80 cyclesfault duration) at 119905 = 066 sec A line recloser is assumed tobe located near bus 7 nearly at themidpoint of the distributorlength and it is opened after 012 sec from the fault instant (6cycles after fault occurrence) at 119905 = 062 sec The recloser isstill open for 20 sec from the opening instant The obtainedresults are obtained in Figure 12 fromwhich the following canbe concluded

(i) DFIG wind turbine and conventional synchronousgenerator can maintain the load voltage of the iso-lated area within the normal limit (plusmn5) during therecloser opening preventing the interruption

(ii) Although the PMSG can restore the isolated areavoltage after fault removing to an acceptable valueit cannot keep it stable (a b and c) because of theincapability of DC-link voltage restoration (d)

(iii) In the case of the FSIG it is noted that the isolatedarea is subjected to voltage interruption followed byvoltage sag which is worse than without DG case

(iv) Theoccurrence of the SLG fault leads to a voltage swellon the unfaulted phases (c) where the DG utilizationincreases the voltage swell problem slightly


0

02

04

06

08

1Vo

ltage

(pu)

05 1 2 25 3 4 50Time (sec)

FSIGDFIG

PMSGSynch

(a) Terminal voltage of the DGs (phase A)

0

02

04

06

0809

1

Volta

ge (p

u)

05 1 2 25 3 4 50Time (sec)

No DGFSIGDFIG

PMSGSynch

(b) Voltage of bus 15 (phase A)

0

02

04

06

0809

111

Volta

ge (p

u)

0 1 2 25 3 4 505Time (sec)

1

11

0605

No DGFSIGDFIG

PMSGSynch

(c) Voltage of bus 15 (phases B and C)

DFIGPMSG

09

1

11

12

13

14

DC-

link

volta

ge (p

u)

05 1 15 2 25 3 35 40Time (sec)

(d) DC-link voltage of DFIG and PMSG

Figure 12 DGs performance after being subjected to SLG fault on a system containing recloser

5 Voltage Fluctuation and Flicker

One of the important power quality problems is the voltageflicker which is the result of voltage fluctuations Grid-connected wind turbines may have considerable fluctuationsin the output powers which depend on the wind turbinetype The power generated by the wind turbine fluctuates asit is much more variable than that produced by conventionalgenerators

From a signal analyzing point of view the voltage flickeris defined as a low-frequency (5 15Hz) modulation of thenetwork voltage at 6050Hz and the flickermeter is used toseparate the carrier from the modulating wave and weighthe effects of the latter based on human sensitivity to thedisturbance and generate the instantaneous sensation ofthe flicker 119878(119905) and the short-term flicker 119875st The IECflickermeter is developed in MatlabSimulink as shown inFigure 13 and is used to calculate 119878(119905) and 119875st [20ndash22] Theadmissible limit of the flicker produced by the distributedgenerators on the MV grid is 035 for 119875st [23]

Two case studies are considered in this section The firstcase studied the voltage flicker resulting from the differentwind turbine types assuming wind speed variations In thesecond case study it is assumed that a constant wind speedand the voltage flicker resulted from a connected pulsatingload

Get cumulativeprobability function (CPF)

curve in 10 minutespiecewise linear

interpolation

band-passfilter

6th-orderbutterworth

low-pass filter

Gain control and1st-order sliding

mean filter

Uin

Pst

005 35 Hz( UinUref

)2 S(t)

Calculate Pst by

Figure 13 Block diagram of the flickermeter

89

101112131415

Win

d sp

eed

(ms

ec)

11 12 13 14 15 16 17 18 19 21Time (min)

Figure 14 The assumed wind speed variation

Now considering the first case study it is assumed thatthe steep wind speed variation shown in Figure 14 is appliedto each of the considered wind turbines The wind turbine of


DFIG (UPF) FSIG

040608

112141618

22224

Activ

e pow

er (M

W)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)

DFIG (VC)

(a) Wind turbines output active powers for the assumed wind speed

DFIG (UPF)

FSIGminus04

minus02

0

02

04

06

08

Reac

tive p

ower

(MVA

R)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)

(b) Wind turbines output reactive powers for the assumed wind speed

DFIG (UPF)FSIG

0950955

0960965

0970975

0980985

099

PCC

volta

ge (p

u)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)

(c) Voltage at bus 15 (the wind turbine PCC)

Figure 15 Performance of the different wind turbines generators for the assumed wind speed variation

Table 5 Average short-term flicker 119875st for a duration of 10 minutesat bus 15

FSIG DFIG PMSG119881119862119881

119862UPF

0464 0322 0368 0328

the 20MW rated power is assumed to be connected at bus15 Figure 15 shows the performance of the three consideredwind turbines generators The instantaneous voltage flickeracross the wind turbine PCC is shown in Figure 16 while thecorresponding average short-term flicker values are given inTable 5 From the obtained results the following are clear

(i) The active and reactive power change profile of theFSIG increases the distribution system flicker Thesteep change of output active power and reactivepower leads to a voltage fluctuationwith unacceptableflicker sensation (119875st = 0464which is greater than thelimit that is 035)

(ii) Despite reactive power controllability of both DFIGand PMSG with voltage control operating modethe DFIG performance is more acceptable than thePMSG The two paths of active and reactive powercontrol in DFIG (RSC and NSC) are leading tosmooth change in theDFIGoutput active and reactivepower and terminal voltage as compared with thePMSG

Now assuming a constant wind speed the performanceof the DGs under variable load condition will be studied inthis sectionThe load variation shown in Figure 17 is assumedto be at bus 13The short-term flicker 119875st at buses 9 11 13 and15 is listed in Table 6 for different connection points of eachDG From the obtained results the following are found

(i) The utilization of the DGs despite the type and con-nection point reduces the distribution system voltageshort-term flicker

(ii) The connection of theDGs despite the type upstreampulsating load connection point increases the systemvoltage short-term flicker at all the considered distri-bution buses

(iii) The connection of the DGs downstream variable load(at bus 15) or at its terminal (at bus 13) reduces thevoltage flicker at all the considered distribution buses

(iv) The voltage control of the synchronous generator canreduce the voltage variation (119881max minus 119881min) so thevoltage flicker is reduced compared with other DGs

(v) The UPF operating mode used with DFIG in thiscase can be considered the worst case for all connec-tion points among all considered DGs technologies

(vi) Although the DFIG and PMSG operate with voltagecontrol mode the voltage variation (119881max minus 119881min) islarger than that in case of FSIG


0

005

01

015

02

025

03

Inst

anta

neou

s flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(a) FSIG as a DG

DFIG with UPF mode

0

001

002

003

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

0

001

002

003

004

005

006

Insta

ntan

eous

flic

ker

2 4 6 8 100Time (min)

DFIG with VC mode

(b) DFIG as a DG

0001002003004005006007008009

01

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(c) PMSG as a DG

Figure 16 Instantaneous flicker sensation at PCC (bus 15)

6 Harmonic Distortion

The harmonic current distortion in the distribution systemis generated by the nonlinear loads interacting with powersystem impedance and gives rise to the harmonic problemsThe effect of harmonics in the power system can lead todegradation of power quality at the consumerrsquos terminalincrease of power losses and malfunction in communicationsystemThe degree of variation is assessed at the PCC whereconsumer and supplier areas of responsibility meet Windturbines DGs can also contribute to the harmonic distortionof the voltage waveform In the first edition of IEC 61400-21only wind turbines with power converters should be testedfor harmonics However this will probably be changed inthe second edition requiring measurements of harmoniccurrents for all types of wind turbines [24ndash26]

According to [2] when the DG is serving balanced linearloads harmonic current injection at the PCC should not

exceed the limits stated in Table 7 Therefore it is requiredto determine the current and voltage harmonic distortionproduced from each wind turbine during constant and vari-able wind speed The wind speed profile shown in Figure 18is applied to the rotor of different wind turbine types (eachof 2MW rated power) connected to bus 15 see Figure 1 TheTDD of wind turbines injected current is shown in Figure 19and the voltage THD at the wind turbine connection pointldquobus 15rdquo is shown in Figure 20 From the obtained results thefollowing can be concluded

(i) For constant or variable wind speed the values of theinjected current TDD and the terminal voltage THDare within the admissible range

(ii) Only the FSIG is affected with wind speed variationwhere the TDD and THD nearly equal zero forconstant wind speed region (119905 lt 10 sec)


Table 6 Average short-term flicker 119875st at buses 9 11 13 and 15 for different connection points of the considered DGs

Bus number Without DG FSIG DFIG PMSG 119881119862

Synch 119881119862

119881119862

UPFDG connected at bus 9

9 0938 0687 0727 0753 0745 048711 1289 0990 1017 1051 1041 072613 1736 1385 1391 1433 1421 104515 1735 1384 1390 1432 1420 1044

DG connected at bus 119 0938 0629 0701 0723 0718 043911 1289 0892 0978 1014 1001 061313 1736 1268 1343 1391 1375 090615 1735 1266 1342 1390 1374 0904



04

05

06

07

08

09

1

11

Load

activ

e pow

er (M

W)

6 7 8 9 105Time (min)

Figure 17 Load active power variation profile at bus 13 for aduration of 5min

Table 7 Maximum allowable harmonic distortion at the DG PCC

Total Demand Distortion (TDD) ofthe DG injected current

Total HarmonicDistortion (THD)at the DG PCC

50 50

Now it is required to determine the effect of nonlinearload on the voltage THD of the distribution system contain-ing the previously mentioned DGs The input mechanicalpower of the DGs is assumed in this case to be constantAlso the effect of DG connection point is determinedFigure 21 shows the voltage and current at bus 13 to whichthe nonlinear load is connected Figure 22 shows the voltage

9

10

11

12

13

14

Win

d sp

eed

(ms

ec)

10 12 14 16 18 20 22 248Time (sec)


THD at the distribution system different buses at differentconnection points of each DG From the obtained results thefollowing can be concluded

(i) Despite theDG type the THDnearly does not changeafter wind turbine DG connection

(ii) The connection point of the wind turbine DG has noeffect on the voltage THD

7 DGs Penetration Ratio and ConnectionPoint Effect on the Distributor Losses

Although the active power losses in the distribution systemare not a technical power quality factor that can limit theamount of the penetrated DGs they are considered as animportant economical factor [17] Therefore in this sectionthe active power losses of the distribution system shown


FSIG

0

05

1

15

2

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

08

09

1

11

12

13

10 12 14 16 18 20 22 248Time (sec)

PMSG DG

10 12 14 16 18 20 22 248Time (sec)

06065

07075

08085

09095

1105

11

Figure 19 Total Demand Distortion (TDD) of wind turbinesinjected current

Table 8 Active power losses (in MW)

Number ofturbines FSIG DFIG PMSG Synch

119881119862

UPFMaximum demand (losses without DG equal 02277)

1 01855 01445 01491 01501 017282 02342 01737 01787 01803 020163 03817 02939 03015 03037 031664 06367 05007 05129 05159 05183

Minimum demand (losses without DG equal 00027)1 00428 00642 00579 00686 004022 01597 02060 02116 02169 014973 03530 04263 04380 04458 032854 06267 07237 07424 07616 06167

in Figure 1 are determined for different scenarios of theconnected DGs and their connection points

Firstly each of the considered DG types is assumed to beconnected to bus 15 and the distributor active power losses arecalculated assuming different penetration ratios and loadingcondition The results are presented in Table 8 The valuesof the active power losses for the case without DGs are

PMSG DG

085

09

095

10 12 14 16 18 20 22 248Time (sec)

FSIG DG

0

01

02

0

01

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

104

106

108

11

112

114

116

118

10 12 14 16 18 20 22 248Time (sec)

Figure 20 Voltage Total Harmonic Distortion (THD) of windturbines PCC

V

I

minus15

minus1

minus05

0

05

1

15

Load

V an

d I a

t bus

13

(pu)

1001 1002 1003 1004 100510Time (sec)

Figure 21 The nonlinear load voltage and current at bus 13

also shown From the obtained results the following can beconcluded

(i) For Maximum Loading Condition The adoption ofvoltage control operation mode (with DFIG PMSGand Synch generator) leads to the largest reductionof power losses because these generators can supply


PMSG DG

(2)(6)

(1)

(3)

(4) (5)

01234567

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

DFIG DG(1) (6)

(3)(2)(5)(4)

0

1

2

3

4

5

6

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

(2)

FSIG DG

(4)

(1)

(6)(3)

(5)

0

1

2

3

4

5

6TH

D (

)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

(1) DG at bus 7(2) DG at bus 9(3) DG at bus 11

(4) DG at bus 13(5) DG at bus 15(6) No DG





Figure 22 Voltage Total Harmonic Distortion (THD) of thedistribution buses

the active and reactive loads locally decreasing themagnitude of the distribution feeders current On theother hand the usage of FSIG does not cause a greatreduction in the active power losses In this case thegenerator consumes reactive power from the networkraising the magnitude of the currents circulating inthe feeders The losses behaviour in the presence ofunity power factor (with synchronous generators inthis case) is situated between the other two casesbecause these generators supply locally active powerbut do not provide or consume reactive power

(ii) For Minimum Loading Condition The presence of theDGs increases the active power losses independentof the generator employed In this situation a largeamount of active power generated is exported to thesubstation adversely influencing the distribution sys-tem losses The usage of the voltage control operatingmode can be related to the worst case under lossesviewpoint because the generator consumes a largeamount of reactive power to keep the terminal voltageat 1 pu

Now to determine the effect of the DG connection pointon the distributor active power losses it is assumed that theDG is connected to buses 3 5 7 9 11 13 and 15 At eachconnection point different penetration ratios are consideredThe considered DGs are the FSIG the DFIG with voltagecontrol operating mode and the PMSG with UPF operatingmode The results are shown in Figure 23 from which thefollowing can be concluded

(i) Theminimization of power losses depends explicitlyon the connection point of theDG and its penetrationratios

(ii) For small penetration ratios the suggested connec-tion point of any one of the considered wind turbineDGs is near the far end of the distribution systemWith penetration ratio increase the suitable DGconnection point comes near the substation side

(iii) The use of voltage control mode with DFIG or PMSGreduces the power losses despite the connection pointor the DG penetration ratio

8 Conclusions

In this paper a comprehensive study of the power qualityproblems for a considered 15-bus radial distribution systemwith embedded DGs has been introducedThe power qualitystudies are carried out in a comparison aspect between theconventional synchronous generator as DGs are widely inuse at present and the different wind turbines technologieswhich represent the foresightedness of the DGs The absenceof DGs is assumed as a base case for the studies From theresults obtained in this paper the following conclusions havebeen obtained

(1) The utilization of the DGs may be one of the powerquality enhancementmethods according to some fac-tors such as theDG type operatingmode penetrationvalue and connection point

(2) The wind turbine DGs-based DFIG and PMSG withvoltage control mode have nearly the same perfor-mance of conventional synchronous generator duringsteady state and transient operating conditions

(3) The penetration ratio of wind turbine DGs operatingwith voltage control mode can reach 100 maximumdistribution system loading without violating theadmissible voltage in the steady states or losing systemstability during transient conditions


One FSIG unit is connectedTwo FSIG units are connectedThree FSIG units are connectedFour FSIG units are connected

No DG(1)(2)

(3)

(4)

0

01

02

03

04

05

06

07Po

wer

loss

es (M

W)

5 7 9 11 13 153Connection bus of DG

(a) The connected generator is FSIG

One DFIG unit is connectedTwo DFIG units are connectedThree DFIG units are connectedFour DFIG units are connected

(1)(2)

(3)

(4)

No DG


0

01

02

03

04

05

Pow

er lo

sses

(MW

)

(b) The connected generator is DFIG with voltage control operatingmode

One PMSG unit is connectedTwo PMSG units are connectedThree PMSG units are connectedFour PMSG units are connected

(1)(2)(3)

(4)

No DG

0

01

02

03

04

05

Pow

er lo

sses

(MW

)


(c) The connected generator is PMSG with UPF operating mode

Figure 23 Wind turbine DG connection point and penetration ratio effect on the distribution system power losses

(4) The power quality of the distribution system is verysensitive to the connection point of the embeddedDGs where the following are considered

(i) The distribution system load voltage improve-ment in the steady state requires a connectionof the DG near the far end of the distributordespite its penetration

(ii) Active power losses minimization depends sig-nificantly on the DG connection point and itspenetration ratio The connection point shouldbe near the distribution far end for minimumpenetration ratios and must be transposed for-ward themain substation with penetration ratioincrease

(iii) The voltage sag problem can be reduced by con-necting the DG downstream source of voltagesag problem

(iv) The voltage interruption problem can be solvedby suitable connection of the DG with respectto protection systems The DFIG wind turbine

with voltage control mode can prevent thevoltage interruption in the distribution isolatedarea similar to synchronous generators

(v) The connection of the DG despite its typedownstream voltage flicker sources reduces thevoltage flicker problem at all distribution systembuses

(vi) The THD produced from the nonlinear loads isnot affected by the DG despite its type andconnection point

(5) Thevoltage flicker due towind turbine variable outputpower is still within acceptable limits until withpulsating wind speed variation

(6) The main problem of the FSIG wind turbine DGappears manifestly during transient conditions due tothe lack of reactive power support

(7) The DC-link of the DFIG and PMSG representsthe main challenge of these wind turbine operationsduring transient conditions


(8) The disconnection of the wind turbine DGs duringsystem faults listed in interconnecting distributedresources with electric power systems standard mustbe restudied as well as the ability of coordinationbetween the protection devices and the wind turbinecontrol system

Appendix

In this section the systems data are presented(A) Line data in ohm

1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616

(B) Load data in KVA

Load 2 1333 + 119895100Load 3 14667 + 1198951100Load 4 2667 + 119895200Load 5 1600 + 1198951200Load 6 2667 + 119895200Load 7 400 + 119895300Load 8 2667 + 119895200Load 9 5333 + 119895400Load 10 2667 + 119895200Load 11 400 + 119895300Load 12 2667 + 119895200Load 13 400 + 119895300Load 14 2667 + 119895200Load 15 1333 + 119895100

(C) Transformer (T1) data

8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu

(D) Transformer (T2) data

22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu

(E) FSIG wind turbine (2MVA) data

119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s

(F) DFIG wind turbine (2MVA) data

119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840

119897119903= 0160 pu119871119898= 290 pu119867119892= 0685 s119867119879= 432 s119862DC-link = 10000 120583f119881dc-nominal = 1150

(G) PMSG wind turbine (2MVA) data


(H) Synchronous generator (2MVA) data

119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests

The authors declare that they have no competing interests


References

[1] IEC Standards ldquoTesting and measurement techniquesmdashpowerquality measurement methodsrdquo Tech Rep IEC Std 61000-4-302008

[2] IEEE Standard ldquoInterconnecting distributed resources withelectric power systemsrdquo IEEE Std 1547-2003 2003

[3] T Lin and A Domijan ldquoOn power quality indices and real timemeasurementrdquo IEEETransactions on PowerDelivery vol 20 no4 pp 2552ndash2562 2005

[4] C F M Almeida and N Kagan ldquoHarmonic state estimationthrough optimal monitoring systemsrdquo IEEE Transactions onSmart Grid vol 4 no 1 pp 467ndash478 2013

[5] Y-J Shin E J Powers M Grady and A Arapostathis ldquoPowerquality indices for transient disturbancesrdquo IEEE Transactions onPower Delivery vol 21 no 1 pp 253ndash261 2006

[6] C Long M E A Farrag C Zhou and D M HepburnldquoStatistical quantification of voltage violations in distributionnetworks penetrated by small wind turbines and battery electricvehiclesrdquo IEEE Transactions on Power Systems vol 28 no 3 pp2403ndash2411 2013

[7] L Shi S Sun L Yao Y Ni and M Bazargan ldquoEffects of windgeneration intermittency and volatility on power system tran-sient stabilityrdquo IET Renewable Power Generation vol 8 no 5pp 509ndash521 2014

[8] P Kundur Power System Stability and Control McGraw-HillNew York NY USA 1994

[9] J DHurley L N Bize andC RMummert ldquoThe adverse effectsof excitation system var and power factor controllersrdquo IEEETransactions on Energy Conversion vol 14 no 4 pp 1636ndash16411999

[10] LM Fernandez J R Saenz and F Jurado ldquoDynamicmodels ofwind farms with fixed speed wind turbinesrdquo Renewable Energyvol 31 no 8 pp 1203ndash1230 2006

[11] N Jenkins R Allan P Crossley D Kirschen and G StrbacEmbedded Generation Institution of Electrical Engineers Lon-don UK 1st edition 2000

[12] T A Kawady H Shaaban and A El-Sherif ldquoInvestigation ofgrid-support capabilities of doubly fed induction generatorsduring grid faultsrdquo in Proceedings of the IET Conference onRenewable Power Generation (RPG rsquo11) paper 1134 EdinburghScotland September 2011

[13] J B Ekanayake L Holdsworth X Wu and N Jenkins ldquoDy-namic modeling of doubly fed induction generator wind tur-binesrdquo IEEE Transactions on Power Systems vol 18 no 2 pp803ndash809 2003

[14] O Lara N Jenkins J Ekanayake P Cartwright andMHughesWind Energy Generation Modeling and Control John Wiley ampSons 2009

[15] C L Masters ldquoVoltage rise the big issue when connectingembedded generation to long 11 kv overhead linesrdquo PowerEngineering Journal vol 16 no 1 pp 5ndash12 2002

[16] W Freitas J C M Vieira A Morelato L C P da Silva V Fda Costa and F A B Lemos ldquoComparative analysis betweensynchronous and induction machines for distributed genera-tion applicationsrdquo IEEE Transactions on Power Systems vol 21no 1 pp 301ndash311 2006

[17] C L T Borges and D M Falcao ldquoImpact of distributed gener-ation allocation and sizing on reliability losses and voltage pro-filerdquo in Proceedings of the IEEE Bologna Power Tech Conferencevol 2 June 2003

[18] IEEE ldquoIEEE recommended practice for monitoring electricpower qualityrdquo IEEE Standard 1159 2009

[19] R Dugan M Granaghan S Santoso and H Beaty ElectricalPower Systems Quality McGraw-Hill 2004

[20] IEC Standards IEC 61000-4-15 Testing and Measurement Tech-niquesmdashFlickermeter Functional and Design Specifications vol77 IEC Technical Committee 2012

[21] J Gutierrez J Ruiz L Leturiondo and A Lazkano ldquoFlickermeasurement system for wind turbine certificationrdquo IEEETransactions on Instrumentation and Measurement vol 58 no2 pp 375ndash382 2009

[22] IEC ldquoPower performance measurements of electricity produc-ing wind turbinesrdquo IEC 61400-12-1 IEC Technical Committee88 2005

[23] C Naslin O Gonbeau J L Fraisse and T CThai ldquoWind farmintegration-power quality management for French distributionnetworkrdquo in Proceedings of the 18th International Conferenceand Exhibition on Electricity Distribution (CIRED rsquo05) pp 1ndash5Turin Italy June 2005

[24] IEC ldquoTesting and measurement techniquesmdashgeneral guide onharmonics and interharmonics measurements and instrumen-tation for power supply systems and equipment connectedtheretordquo IEC Standard 61000-4-7 2009 edition 21

[25] IEEE Standards ldquoIEEE recommended practices and require-ments for harmonic control in electrical power systemsrdquo IEEEStd 519 1992

[26] IEC Standards ldquoRecommendations for preparing the measure-ments and assessment of power quality characteristics of windturbinesrdquo Tech Rep IEC Std 61400-21 2001

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Power ElectronicsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Submit your manuscripts athttpwwwhindawicom


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RotatingMachinery


EnergyJournal of


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Journal ofEngineeringVolume 2014

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High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


Bus 1 Bus 2 Bus 3 Bus 14 Bus 15

Load 2 Load 14Load 3Load 15T1

DG

T2

Substation

Bus 4

Load 4

66 kV

Bus 575 V

Z14-15Z1 2- Z2 3- Z3 4- middot middot middot

Figure 1 Single line diagram of the considered 15-bus distribution system

+

V

+

++

+

5

UPF control mode

Voltage control mode

Voltage regulator

Var regulator

Qm

Qref = 0minus

minus

minus

Vref

K = 02

Vref = 1

Efdo

KA = 100 TA = 001 minus5

Efd

KTs

Z minus 1

KA

1 + TAS

Figure 2 IEEE type-AC1A excitation system

The steady state voltage profile of the considered system isgiven in Section 3 Section 4 presents a complete study aboutvoltage sag voltage swell and voltage interruption duringload variation and system disturbances Voltage fluctuationand flicker resulting fromwind speed variation and pulsatingloads are analyzed in Section 5 The harmonic distortionsupplied by the wind turbine generators and the nonlinearloads are investigated in Section 6 Section 7 discusses theelectrical power losses and the effect of wind turbine outputpower and connection point on power loss values FinallySection 8 summarizes the main conclusions

2 Configuration of the ConsideredDistribution System

In this paper the 15-bus radial distribution system shown inFigure 1 is considered All the system data are given in theAppendix Each of the feeder sections is represented by seriesRL impedance and the system transformers are modelledby its T-equivalent circuit In the steady state studies theloads are represented by constant power models as is usualin the load flow studies while in the dynamic studies theloads are represented by constant impedanceThe simulationpackage adopted is the Sim-Power Systems for use withMatlabSimulink

The DGs considered in this paper are the conventionalsynchronous generators which arewidely in use at present inaddition to the wind turbine generators which represent theforesightedness of the DGsThewind turbines generators canbe classified as fixed speed and variable speed wind turbinesgenerators The fixed speed induction generator (FSIG) windturbine is equipped with a squirrel-cage induction generatorwhile the variable speed wind turbines can be either a par-tially rated converter- or a fully rated converter-based wind

turbine The partially rated converter-based wind turbinesare always equipped with a double fed induction generator(DFIG) The fully rated converter-based wind turbine canbe equipped with a wound rotor induction generator or aconventional synchronous generator or a permanent mag-net synchronous generator (PMSG) The PMSG is the onecommonly used for avoiding the field current supply neededby wound rotor synchronous generators or because of thereactive power compensation facilities needed by inductiongenerators Furthermore the PMSG removes the need for sliprings

The following subsections summarize themodelling of allthe considered distributed generators

21 Synchronous Generators In this paper the synchronousgenerator is represented by the eight-order model [8] Thereare two different modes of controlling the generator exci-tation system One aims to maintain its terminal voltage(constant voltage control mode) while the other one aimsto maintain its power factor (constant power factor controlmode) [9] The power factor control mode is usually adoptedby independent producers to maximize the active powerproductionThe set points of voltage control and unity powerfactor control mode are depicted in Figure 2

22 FSIG Wind Turbine Figure 3 shows the schematic dia-gram of a fixed speed wind turbine which consists of threemain parts the rotor the drive train and the squirrel-cageinduction generator (SCIG) The dynamic models of therotor and the drive train are given in [10] The SCIG wasrepresented by the fourth-order state-space model and itsmechanical parts were represented by a second-order system[8]The generator needed reactive power was locally supplied


GridSCIG


GB

Capacitor


DFIGGB

NSCRSC



Stator current

RotorP Q QUdc

current






DFIG +minus

PWMPIPI

PIPI

+minus

++

++minusminus

minusminus

minus minus

minus

++

Network

calculation

PIPI

PIPI

++

++

++ +

+

NSC

RSC

PWM

calculation

++minus

minus

Vdc Idg

Iqg

Vdg1

Vs

Qg

Vdg

Vqg

120596sLgiqg

120596sLgidg

Qgs

Ps and Qs

Ps

Qs

Iqr

Idr


Vqr

Vqr1

Vdr

Vdr1


Vlowastdc

Qlowastg

Ilowastdg

Ilowastqg

Plowasts

Qlowasts

Ilowastqr

Ilowastdr




119904





PM synchronous

generator PWM-VSC

GB


Network

Generatorcontrol













PMSG+Network

PIPI

PIPI

+++

++

+


PWM

calculation

PIPI +

+IL


PWM

DR diode rectifier

DRNSC

Vlowastdc

BC boost converter

BC

Vdc IdNVdN

VdN

VdN1

QN

QN

IqN

VqN1 VqN



120596r

minus

minus

minus

minusminus

minus

minus

minus

minus

minus

QlowastN

IlowastdN

IlowastqN

120596lowastref

ILlowastref









(3)

(6)

(2)(1)

(7)(5)

(8)

(4)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus number

095096

098

1

102

104105

Bus v

olta

ge (p

u)


(5) PMSG (UPF)


(6) PMSG (VC)

(4) DFIG (VC)


(2)

(7)

(8)

(6)

(4)

(1)

(3)

(5)

1011015

1021025

1031035

1041045

1051055

106

Bus v

olta

ge (p

u)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus number

(1)(2)(3)(4)

(5)(6)(7)(8)





FSIG 0043 0642DFIG





VI =sum119899119887

119894=1

1003817100381710038171003817119881119892

119894minus 119881119899

119894

1003817100381710038171003817 times 100

sum119899119887

119894=1119881119899

119894

(1)


119881119892






(1)(2)

(3)(5) (7)

(8)

(4)

(6)095

0955096

0965097

0975098

0985099

09951

Volta

ge o

f bus

15

(pu)



(5) PMSG (UPF)


(6) PMSG (VC)

(4) DFIG (VC)








































Bus 3

1 0948 15 0947 15 0949 152 0950 15 0948 15 0953 153 0952 15 0948 15 0956 154 0954 15 0948 15 0959 15

Bus 5

1 0951 15 0961 15 0954 152 0955 15 0968 15 0961 153 0959 15 0971 15 0968 154 0962 15 0973 15 0973 15

Bus 7

1 0951 15 0966 15 0955 152 0956 15 0973 15 0963 153 0960 15 0977 15 0971 154 0963 15 0979 15 0977 15

Bus 9

1 0952 15 0970 15 0957 152 0959 15 0979 15 0966 153 0962 15 0983 15 0975 154 0965 15 0985 15 0982 15

Bus 11

1 0953 15 0975 15 0959 152 0960 15 0984 15 0970 153 0964 15 0988 15 0979 154 0966 15 0990 15 0987 15

Bus 13

1 0954 15 0979 15 0961 152 0961 15 0987 13 0973 153 0965 15 0989 12 0982 104 0965 15 0989 12 0986 9

Bus 15

1 0955 14 0977 11 0962 132 0959 13 0981 11 0972 123 0959 13 0982 10 0977 114 0948 13 0979 10 0978 10





(1)(2)

(3)

(4)

(5)

(6)

07

075

08

085

09

095

1

Volta

ge o

f bus

13

(pu)

10 12 14 16 18 20 22 248Time (sec)

(1) No DG(2) FSIG


(3) DFIG (VC)





Connection bus ofDG


UPF


13 0713 0739 0724 0753 0734

11 0714 0735 0723 0746 0729

9 0715 0731 0722 0739 0725


13 904 729 822 732 878

11 908 748 836 747 881

9 914 769 851 766 888



















0

02

04

06

08

1Vo

ltage

(pu)

05 1 2 25 3 4 50Time (sec)

FSIGDFIG

PMSGSynch


0

02

04

06

0809

1

Volta

ge (p

u)

05 1 2 25 3 4 50Time (sec)

No DGFSIGDFIG

PMSGSynch


0

02

04

06

0809

111

Volta

ge (p

u)

0 1 2 25 3 4 505Time (sec)

1

11

0605

No DGFSIGDFIG

PMSGSynch


DFIGPMSG

09

1

11

12

13

14

DC-

link

volta

ge (p

u)

05 1 15 2 25 3 35 40Time (sec)









interpolation

band-passfilter


low-pass filter


mean filter

Uin

Pst

005 35 Hz( UinUref

)2 S(t)

Calculate Pst by


89

101112131415

Win

d sp

eed

(ms

ec)

11 12 13 14 15 16 17 18 19 21Time (min)




DFIG (UPF) FSIG

040608

112141618

22224

Activ

e pow

er (M

W)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)

DFIG (VC)


DFIG (UPF)

FSIGminus04

minus02

0

02

04

06

08

Reac

tive p

ower

(MVA

R)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)


DFIG (UPF)FSIG

0950955

0960965

0970975

0980985

099

PCC

volta

ge (p

u)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)




FSIG DFIG PMSG119881119862119881

119862UPF

0464 0322 0368 0328












0

005

01

015

02

025

03

Inst

anta

neou

s flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(a) FSIG as a DG

DFIG with UPF mode

0

001

002

003

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

0

001

002

003

004

005

006

Insta

ntan

eous

flic

ker

2 4 6 8 100Time (min)

DFIG with VC mode

(b) DFIG as a DG

0001002003004005006007008009

01

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(c) PMSG as a DG











Synch 119881119862

119881119862


9 0938 0687 0727 0753 0745 048711 1289 0990 1017 1051 1041 072613 1736 1385 1391 1433 1421 104515 1735 1384 1390 1432 1420 1044




04

05

06

07

08

09

1

11

Load

activ

e pow

er (M

W)

6 7 8 9 105Time (min)





50 50


9

10

11

12

13

14

Win

d sp

eed

(ms

ec)

10 12 14 16 18 20 22 248Time (sec)








FSIG

0

05

1

15

2

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

08

09

1

11

12

13

10 12 14 16 18 20 22 248Time (sec)

PMSG DG

10 12 14 16 18 20 22 248Time (sec)

06065

07075

08085

09095

1105

11




119881119862


1 01855 01445 01491 01501 017282 02342 01737 01787 01803 020163 03817 02939 03015 03037 031664 06367 05007 05129 05159 05183




PMSG DG

085

09

095

10 12 14 16 18 20 22 248Time (sec)

FSIG DG

0

01

02

0

01

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

104

106

108

11

112

114

116

118

10 12 14 16 18 20 22 248Time (sec)


V

I

minus15

minus1

minus05

0

05

1

15

Load

V an

d I a

t bus

13

(pu)

1001 1002 1003 1004 100510Time (sec)





PMSG DG

(2)(6)

(1)

(3)

(4) (5)

01234567

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

DFIG DG(1) (6)

(3)(2)(5)(4)

0

1

2

3

4

5

6

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

(2)

FSIG DG

(4)

(1)

(6)(3)

(5)

0

1

2

3

4

5

6TH

D (

)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no














8 Conclusions







No DG(1)(2)

(3)

(4)

0

01

02

03

04

05

06

07Po

wer

loss

es (M

W)




(1)(2)

(3)

(4)

No DG


0

01

02

03

04

05

Pow

er lo

sses

(MW

)



(1)(2)(3)

(4)

No DG

0

01

02

03

04

05

Pow

er lo

sses

(MW

)

















Appendix


1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616




8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s


119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840





119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests



References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















GridSCIG


GB

Capacitor


DFIGGB

NSCRSC



Stator current

RotorP Q QUdc

current






DFIG +minus

PWMPIPI

PIPI

+minus

++

++minusminus

minusminus

minus minus

minus

++

Network

calculation

PIPI

PIPI

++

++

++ +

+

NSC

RSC

PWM

calculation

++minus

minus

Vdc Idg

Iqg

Vdg1

Vs

Qg

Vdg

Vqg

120596sLgiqg

120596sLgidg

Qgs

Ps and Qs

Ps

Qs

Iqr

Idr


Vqr

Vqr1

Vdr

Vdr1


Vlowastdc

Qlowastg

Ilowastdg

Ilowastqg

Plowasts

Qlowasts

Ilowastqr

Ilowastdr




119904





PM synchronous

generator PWM-VSC

GB


Network

Generatorcontrol













PMSG+Network

PIPI

PIPI

+++

++

+


PWM

calculation

PIPI +

+IL


PWM

DR diode rectifier

DRNSC

Vlowastdc

BC boost converter

BC

Vdc IdNVdN

VdN

VdN1

QN

QN

IqN

VqN1 VqN



120596r

minus

minus

minus

minusminus

minus

minus

minus

minus

minus

QlowastN

IlowastdN

IlowastqN

120596lowastref

ILlowastref









(3)

(6)

(2)(1)

(7)(5)

(8)

(4)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus number

095096

098

1

102

104105

Bus v

olta

ge (p

u)


(5) PMSG (UPF)


(6) PMSG (VC)

(4) DFIG (VC)


(2)

(7)

(8)

(6)

(4)

(1)

(3)

(5)

1011015

1021025

1031035

1041045

1051055

106

Bus v

olta

ge (p

u)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus number

(1)(2)(3)(4)

(5)(6)(7)(8)





FSIG 0043 0642DFIG





VI =sum119899119887

119894=1

1003817100381710038171003817119881119892

119894minus 119881119899

119894

1003817100381710038171003817 times 100

sum119899119887

119894=1119881119899

119894

(1)


119881119892






(1)(2)

(3)(5) (7)

(8)

(4)

(6)095

0955096

0965097

0975098

0985099

09951

Volta

ge o

f bus

15

(pu)



(5) PMSG (UPF)


(6) PMSG (VC)

(4) DFIG (VC)








































Bus 3

1 0948 15 0947 15 0949 152 0950 15 0948 15 0953 153 0952 15 0948 15 0956 154 0954 15 0948 15 0959 15

Bus 5

1 0951 15 0961 15 0954 152 0955 15 0968 15 0961 153 0959 15 0971 15 0968 154 0962 15 0973 15 0973 15

Bus 7

1 0951 15 0966 15 0955 152 0956 15 0973 15 0963 153 0960 15 0977 15 0971 154 0963 15 0979 15 0977 15

Bus 9

1 0952 15 0970 15 0957 152 0959 15 0979 15 0966 153 0962 15 0983 15 0975 154 0965 15 0985 15 0982 15

Bus 11

1 0953 15 0975 15 0959 152 0960 15 0984 15 0970 153 0964 15 0988 15 0979 154 0966 15 0990 15 0987 15

Bus 13

1 0954 15 0979 15 0961 152 0961 15 0987 13 0973 153 0965 15 0989 12 0982 104 0965 15 0989 12 0986 9

Bus 15

1 0955 14 0977 11 0962 132 0959 13 0981 11 0972 123 0959 13 0982 10 0977 114 0948 13 0979 10 0978 10





(1)(2)

(3)

(4)

(5)

(6)

07

075

08

085

09

095

1

Volta

ge o

f bus

13

(pu)

10 12 14 16 18 20 22 248Time (sec)

(1) No DG(2) FSIG


(3) DFIG (VC)





Connection bus ofDG


UPF


13 0713 0739 0724 0753 0734

11 0714 0735 0723 0746 0729

9 0715 0731 0722 0739 0725


13 904 729 822 732 878

11 908 748 836 747 881

9 914 769 851 766 888



















0

02

04

06

08

1Vo

ltage

(pu)

05 1 2 25 3 4 50Time (sec)

FSIGDFIG

PMSGSynch


0

02

04

06

0809

1

Volta

ge (p

u)

05 1 2 25 3 4 50Time (sec)

No DGFSIGDFIG

PMSGSynch


0

02

04

06

0809

111

Volta

ge (p

u)

0 1 2 25 3 4 505Time (sec)

1

11

0605

No DGFSIGDFIG

PMSGSynch


DFIGPMSG

09

1

11

12

13

14

DC-

link

volta

ge (p

u)

05 1 15 2 25 3 35 40Time (sec)









interpolation

band-passfilter


low-pass filter


mean filter

Uin

Pst

005 35 Hz( UinUref

)2 S(t)

Calculate Pst by


89

101112131415

Win

d sp

eed

(ms

ec)

11 12 13 14 15 16 17 18 19 21Time (min)




DFIG (UPF) FSIG

040608

112141618

22224

Activ

e pow

er (M

W)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)

DFIG (VC)


DFIG (UPF)

FSIGminus04

minus02

0

02

04

06

08

Reac

tive p

ower

(MVA

R)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)


DFIG (UPF)FSIG

0950955

0960965

0970975

0980985

099

PCC

volta

ge (p

u)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)




FSIG DFIG PMSG119881119862119881

119862UPF

0464 0322 0368 0328












0

005

01

015

02

025

03

Inst

anta

neou

s flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(a) FSIG as a DG

DFIG with UPF mode

0

001

002

003

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

0

001

002

003

004

005

006

Insta

ntan

eous

flic

ker

2 4 6 8 100Time (min)

DFIG with VC mode

(b) DFIG as a DG

0001002003004005006007008009

01

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(c) PMSG as a DG











Synch 119881119862

119881119862


9 0938 0687 0727 0753 0745 048711 1289 0990 1017 1051 1041 072613 1736 1385 1391 1433 1421 104515 1735 1384 1390 1432 1420 1044




04

05

06

07

08

09

1

11

Load

activ

e pow

er (M

W)

6 7 8 9 105Time (min)





50 50


9

10

11

12

13

14

Win

d sp

eed

(ms

ec)

10 12 14 16 18 20 22 248Time (sec)








FSIG

0

05

1

15

2

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

08

09

1

11

12

13

10 12 14 16 18 20 22 248Time (sec)

PMSG DG

10 12 14 16 18 20 22 248Time (sec)

06065

07075

08085

09095

1105

11




119881119862


1 01855 01445 01491 01501 017282 02342 01737 01787 01803 020163 03817 02939 03015 03037 031664 06367 05007 05129 05159 05183




PMSG DG

085

09

095

10 12 14 16 18 20 22 248Time (sec)

FSIG DG

0

01

02

0

01

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

104

106

108

11

112

114

116

118

10 12 14 16 18 20 22 248Time (sec)


V

I

minus15

minus1

minus05

0

05

1

15

Load

V an

d I a

t bus

13

(pu)

1001 1002 1003 1004 100510Time (sec)





PMSG DG

(2)(6)

(1)

(3)

(4) (5)

01234567

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

DFIG DG(1) (6)

(3)(2)(5)(4)

0

1

2

3

4

5

6

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

(2)

FSIG DG

(4)

(1)

(6)(3)

(5)

0

1

2

3

4

5

6TH

D (

)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no














8 Conclusions







No DG(1)(2)

(3)

(4)

0

01

02

03

04

05

06

07Po

wer

loss

es (M

W)




(1)(2)

(3)

(4)

No DG


0

01

02

03

04

05

Pow

er lo

sses

(MW

)



(1)(2)(3)

(4)

No DG

0

01

02

03

04

05

Pow

er lo

sses

(MW

)

















Appendix


1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616




8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s


119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840





119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests



References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















PM synchronous

generator PWM-VSC

GB


Network

Generatorcontrol













PMSG+Network

PIPI

PIPI

+++

++

+


PWM

calculation

PIPI +

+IL


PWM

DR diode rectifier

DRNSC

Vlowastdc

BC boost converter

BC

Vdc IdNVdN

VdN

VdN1

QN

QN

IqN

VqN1 VqN



120596r

minus

minus

minus

minusminus

minus

minus

minus

minus

minus

QlowastN

IlowastdN

IlowastqN

120596lowastref

ILlowastref









(3)

(6)

(2)(1)

(7)(5)

(8)

(4)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus number

095096

098

1

102

104105

Bus v

olta

ge (p

u)


(5) PMSG (UPF)


(6) PMSG (VC)

(4) DFIG (VC)


(2)

(7)

(8)

(6)

(4)

(1)

(3)

(5)

1011015

1021025

1031035

1041045

1051055

106

Bus v

olta

ge (p

u)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus number

(1)(2)(3)(4)

(5)(6)(7)(8)





FSIG 0043 0642DFIG





VI =sum119899119887

119894=1

1003817100381710038171003817119881119892

119894minus 119881119899

119894

1003817100381710038171003817 times 100

sum119899119887

119894=1119881119899

119894

(1)


119881119892






(1)(2)

(3)(5) (7)

(8)

(4)

(6)095

0955096

0965097

0975098

0985099

09951

Volta

ge o

f bus

15

(pu)



(5) PMSG (UPF)


(6) PMSG (VC)

(4) DFIG (VC)








































Bus 3

1 0948 15 0947 15 0949 152 0950 15 0948 15 0953 153 0952 15 0948 15 0956 154 0954 15 0948 15 0959 15

Bus 5

1 0951 15 0961 15 0954 152 0955 15 0968 15 0961 153 0959 15 0971 15 0968 154 0962 15 0973 15 0973 15

Bus 7

1 0951 15 0966 15 0955 152 0956 15 0973 15 0963 153 0960 15 0977 15 0971 154 0963 15 0979 15 0977 15

Bus 9

1 0952 15 0970 15 0957 152 0959 15 0979 15 0966 153 0962 15 0983 15 0975 154 0965 15 0985 15 0982 15

Bus 11

1 0953 15 0975 15 0959 152 0960 15 0984 15 0970 153 0964 15 0988 15 0979 154 0966 15 0990 15 0987 15

Bus 13

1 0954 15 0979 15 0961 152 0961 15 0987 13 0973 153 0965 15 0989 12 0982 104 0965 15 0989 12 0986 9

Bus 15

1 0955 14 0977 11 0962 132 0959 13 0981 11 0972 123 0959 13 0982 10 0977 114 0948 13 0979 10 0978 10





(1)(2)

(3)

(4)

(5)

(6)

07

075

08

085

09

095

1

Volta

ge o

f bus

13

(pu)

10 12 14 16 18 20 22 248Time (sec)

(1) No DG(2) FSIG


(3) DFIG (VC)





Connection bus ofDG


UPF


13 0713 0739 0724 0753 0734

11 0714 0735 0723 0746 0729

9 0715 0731 0722 0739 0725


13 904 729 822 732 878

11 908 748 836 747 881

9 914 769 851 766 888



















0

02

04

06

08

1Vo

ltage

(pu)

05 1 2 25 3 4 50Time (sec)

FSIGDFIG

PMSGSynch


0

02

04

06

0809

1

Volta

ge (p

u)

05 1 2 25 3 4 50Time (sec)

No DGFSIGDFIG

PMSGSynch


0

02

04

06

0809

111

Volta

ge (p

u)

0 1 2 25 3 4 505Time (sec)

1

11

0605

No DGFSIGDFIG

PMSGSynch


DFIGPMSG

09

1

11

12

13

14

DC-

link

volta

ge (p

u)

05 1 15 2 25 3 35 40Time (sec)









interpolation

band-passfilter


low-pass filter


mean filter

Uin

Pst

005 35 Hz( UinUref

)2 S(t)

Calculate Pst by


89

101112131415

Win

d sp

eed

(ms

ec)

11 12 13 14 15 16 17 18 19 21Time (min)




DFIG (UPF) FSIG

040608

112141618

22224

Activ

e pow

er (M

W)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)

DFIG (VC)


DFIG (UPF)

FSIGminus04

minus02

0

02

04

06

08

Reac

tive p

ower

(MVA

R)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)


DFIG (UPF)FSIG

0950955

0960965

0970975

0980985

099

PCC

volta

ge (p

u)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)




FSIG DFIG PMSG119881119862119881

119862UPF

0464 0322 0368 0328












0

005

01

015

02

025

03

Inst

anta

neou

s flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(a) FSIG as a DG

DFIG with UPF mode

0

001

002

003

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

0

001

002

003

004

005

006

Insta

ntan

eous

flic

ker

2 4 6 8 100Time (min)

DFIG with VC mode

(b) DFIG as a DG

0001002003004005006007008009

01

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(c) PMSG as a DG











Synch 119881119862

119881119862


9 0938 0687 0727 0753 0745 048711 1289 0990 1017 1051 1041 072613 1736 1385 1391 1433 1421 104515 1735 1384 1390 1432 1420 1044




04

05

06

07

08

09

1

11

Load

activ

e pow

er (M

W)

6 7 8 9 105Time (min)





50 50


9

10

11

12

13

14

Win

d sp

eed

(ms

ec)

10 12 14 16 18 20 22 248Time (sec)








FSIG

0

05

1

15

2

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

08

09

1

11

12

13

10 12 14 16 18 20 22 248Time (sec)

PMSG DG

10 12 14 16 18 20 22 248Time (sec)

06065

07075

08085

09095

1105

11




119881119862


1 01855 01445 01491 01501 017282 02342 01737 01787 01803 020163 03817 02939 03015 03037 031664 06367 05007 05129 05159 05183




PMSG DG

085

09

095

10 12 14 16 18 20 22 248Time (sec)

FSIG DG

0

01

02

0

01

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

104

106

108

11

112

114

116

118

10 12 14 16 18 20 22 248Time (sec)


V

I

minus15

minus1

minus05

0

05

1

15

Load

V an

d I a

t bus

13

(pu)

1001 1002 1003 1004 100510Time (sec)





PMSG DG

(2)(6)

(1)

(3)

(4) (5)

01234567

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

DFIG DG(1) (6)

(3)(2)(5)(4)

0

1

2

3

4

5

6

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

(2)

FSIG DG

(4)

(1)

(6)(3)

(5)

0

1

2

3

4

5

6TH

D (

)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no














8 Conclusions







No DG(1)(2)

(3)

(4)

0

01

02

03

04

05

06

07Po

wer

loss

es (M

W)




(1)(2)

(3)

(4)

No DG


0

01

02

03

04

05

Pow

er lo

sses

(MW

)



(1)(2)(3)

(4)

No DG

0

01

02

03

04

05

Pow

er lo

sses

(MW

)

















Appendix


1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616




8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s


119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840





119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests



References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















(3)

(6)

(2)(1)

(7)(5)

(8)

(4)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus number

095096

098

1

102

104105

Bus v

olta

ge (p

u)


(5) PMSG (UPF)


(6) PMSG (VC)

(4) DFIG (VC)


(2)

(7)

(8)

(6)

(4)

(1)

(3)

(5)

1011015

1021025

1031035

1041045

1051055

106

Bus v

olta

ge (p

u)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus number

(1)(2)(3)(4)

(5)(6)(7)(8)





FSIG 0043 0642DFIG





VI =sum119899119887

119894=1

1003817100381710038171003817119881119892

119894minus 119881119899

119894

1003817100381710038171003817 times 100

sum119899119887

119894=1119881119899

119894

(1)


119881119892






(1)(2)

(3)(5) (7)

(8)

(4)

(6)095

0955096

0965097

0975098

0985099

09951

Volta

ge o

f bus

15

(pu)



(5) PMSG (UPF)


(6) PMSG (VC)

(4) DFIG (VC)








































Bus 3

1 0948 15 0947 15 0949 152 0950 15 0948 15 0953 153 0952 15 0948 15 0956 154 0954 15 0948 15 0959 15

Bus 5

1 0951 15 0961 15 0954 152 0955 15 0968 15 0961 153 0959 15 0971 15 0968 154 0962 15 0973 15 0973 15

Bus 7

1 0951 15 0966 15 0955 152 0956 15 0973 15 0963 153 0960 15 0977 15 0971 154 0963 15 0979 15 0977 15

Bus 9

1 0952 15 0970 15 0957 152 0959 15 0979 15 0966 153 0962 15 0983 15 0975 154 0965 15 0985 15 0982 15

Bus 11

1 0953 15 0975 15 0959 152 0960 15 0984 15 0970 153 0964 15 0988 15 0979 154 0966 15 0990 15 0987 15

Bus 13

1 0954 15 0979 15 0961 152 0961 15 0987 13 0973 153 0965 15 0989 12 0982 104 0965 15 0989 12 0986 9

Bus 15

1 0955 14 0977 11 0962 132 0959 13 0981 11 0972 123 0959 13 0982 10 0977 114 0948 13 0979 10 0978 10





(1)(2)

(3)

(4)

(5)

(6)

07

075

08

085

09

095

1

Volta

ge o

f bus

13

(pu)

10 12 14 16 18 20 22 248Time (sec)

(1) No DG(2) FSIG


(3) DFIG (VC)





Connection bus ofDG


UPF


13 0713 0739 0724 0753 0734

11 0714 0735 0723 0746 0729

9 0715 0731 0722 0739 0725


13 904 729 822 732 878

11 908 748 836 747 881

9 914 769 851 766 888



















0

02

04

06

08

1Vo

ltage

(pu)

05 1 2 25 3 4 50Time (sec)

FSIGDFIG

PMSGSynch


0

02

04

06

0809

1

Volta

ge (p

u)

05 1 2 25 3 4 50Time (sec)

No DGFSIGDFIG

PMSGSynch


0

02

04

06

0809

111

Volta

ge (p

u)

0 1 2 25 3 4 505Time (sec)

1

11

0605

No DGFSIGDFIG

PMSGSynch


DFIGPMSG

09

1

11

12

13

14

DC-

link

volta

ge (p

u)

05 1 15 2 25 3 35 40Time (sec)









interpolation

band-passfilter


low-pass filter


mean filter

Uin

Pst

005 35 Hz( UinUref

)2 S(t)

Calculate Pst by


89

101112131415

Win

d sp

eed

(ms

ec)

11 12 13 14 15 16 17 18 19 21Time (min)




DFIG (UPF) FSIG

040608

112141618

22224

Activ

e pow

er (M

W)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)

DFIG (VC)


DFIG (UPF)

FSIGminus04

minus02

0

02

04

06

08

Reac

tive p

ower

(MVA

R)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)


DFIG (UPF)FSIG

0950955

0960965

0970975

0980985

099

PCC

volta

ge (p

u)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)




FSIG DFIG PMSG119881119862119881

119862UPF

0464 0322 0368 0328












0

005

01

015

02

025

03

Inst

anta

neou

s flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(a) FSIG as a DG

DFIG with UPF mode

0

001

002

003

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

0

001

002

003

004

005

006

Insta

ntan

eous

flic

ker

2 4 6 8 100Time (min)

DFIG with VC mode

(b) DFIG as a DG

0001002003004005006007008009

01

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(c) PMSG as a DG











Synch 119881119862

119881119862


9 0938 0687 0727 0753 0745 048711 1289 0990 1017 1051 1041 072613 1736 1385 1391 1433 1421 104515 1735 1384 1390 1432 1420 1044




04

05

06

07

08

09

1

11

Load

activ

e pow

er (M

W)

6 7 8 9 105Time (min)





50 50


9

10

11

12

13

14

Win

d sp

eed

(ms

ec)

10 12 14 16 18 20 22 248Time (sec)








FSIG

0

05

1

15

2

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

08

09

1

11

12

13

10 12 14 16 18 20 22 248Time (sec)

PMSG DG

10 12 14 16 18 20 22 248Time (sec)

06065

07075

08085

09095

1105

11




119881119862


1 01855 01445 01491 01501 017282 02342 01737 01787 01803 020163 03817 02939 03015 03037 031664 06367 05007 05129 05159 05183




PMSG DG

085

09

095

10 12 14 16 18 20 22 248Time (sec)

FSIG DG

0

01

02

0

01

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

104

106

108

11

112

114

116

118

10 12 14 16 18 20 22 248Time (sec)


V

I

minus15

minus1

minus05

0

05

1

15

Load

V an

d I a

t bus

13

(pu)

1001 1002 1003 1004 100510Time (sec)





PMSG DG

(2)(6)

(1)

(3)

(4) (5)

01234567

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

DFIG DG(1) (6)

(3)(2)(5)(4)

0

1

2

3

4

5

6

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

(2)

FSIG DG

(4)

(1)

(6)(3)

(5)

0

1

2

3

4

5

6TH

D (

)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no














8 Conclusions







No DG(1)(2)

(3)

(4)

0

01

02

03

04

05

06

07Po

wer

loss

es (M

W)




(1)(2)

(3)

(4)

No DG


0

01

02

03

04

05

Pow

er lo

sses

(MW

)



(1)(2)(3)

(4)

No DG

0

01

02

03

04

05

Pow

er lo

sses

(MW

)

















Appendix


1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616




8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s


119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840





119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests



References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of















































Bus 3

1 0948 15 0947 15 0949 152 0950 15 0948 15 0953 153 0952 15 0948 15 0956 154 0954 15 0948 15 0959 15

Bus 5

1 0951 15 0961 15 0954 152 0955 15 0968 15 0961 153 0959 15 0971 15 0968 154 0962 15 0973 15 0973 15

Bus 7

1 0951 15 0966 15 0955 152 0956 15 0973 15 0963 153 0960 15 0977 15 0971 154 0963 15 0979 15 0977 15

Bus 9

1 0952 15 0970 15 0957 152 0959 15 0979 15 0966 153 0962 15 0983 15 0975 154 0965 15 0985 15 0982 15

Bus 11

1 0953 15 0975 15 0959 152 0960 15 0984 15 0970 153 0964 15 0988 15 0979 154 0966 15 0990 15 0987 15

Bus 13

1 0954 15 0979 15 0961 152 0961 15 0987 13 0973 153 0965 15 0989 12 0982 104 0965 15 0989 12 0986 9

Bus 15

1 0955 14 0977 11 0962 132 0959 13 0981 11 0972 123 0959 13 0982 10 0977 114 0948 13 0979 10 0978 10





(1)(2)

(3)

(4)

(5)

(6)

07

075

08

085

09

095

1

Volta

ge o

f bus

13

(pu)

10 12 14 16 18 20 22 248Time (sec)

(1) No DG(2) FSIG


(3) DFIG (VC)





Connection bus ofDG


UPF


13 0713 0739 0724 0753 0734

11 0714 0735 0723 0746 0729

9 0715 0731 0722 0739 0725


13 904 729 822 732 878

11 908 748 836 747 881

9 914 769 851 766 888



















0

02

04

06

08

1Vo

ltage

(pu)

05 1 2 25 3 4 50Time (sec)

FSIGDFIG

PMSGSynch


0

02

04

06

0809

1

Volta

ge (p

u)

05 1 2 25 3 4 50Time (sec)

No DGFSIGDFIG

PMSGSynch


0

02

04

06

0809

111

Volta

ge (p

u)

0 1 2 25 3 4 505Time (sec)

1

11

0605

No DGFSIGDFIG

PMSGSynch


DFIGPMSG

09

1

11

12

13

14

DC-

link

volta

ge (p

u)

05 1 15 2 25 3 35 40Time (sec)









interpolation

band-passfilter


low-pass filter


mean filter

Uin

Pst

005 35 Hz( UinUref

)2 S(t)

Calculate Pst by


89

101112131415

Win

d sp

eed

(ms

ec)

11 12 13 14 15 16 17 18 19 21Time (min)




DFIG (UPF) FSIG

040608

112141618

22224

Activ

e pow

er (M

W)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)

DFIG (VC)


DFIG (UPF)

FSIGminus04

minus02

0

02

04

06

08

Reac

tive p

ower

(MVA

R)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)


DFIG (UPF)FSIG

0950955

0960965

0970975

0980985

099

PCC

volta

ge (p

u)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)




FSIG DFIG PMSG119881119862119881

119862UPF

0464 0322 0368 0328












0

005

01

015

02

025

03

Inst

anta

neou

s flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(a) FSIG as a DG

DFIG with UPF mode

0

001

002

003

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

0

001

002

003

004

005

006

Insta

ntan

eous

flic

ker

2 4 6 8 100Time (min)

DFIG with VC mode

(b) DFIG as a DG

0001002003004005006007008009

01

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(c) PMSG as a DG











Synch 119881119862

119881119862


9 0938 0687 0727 0753 0745 048711 1289 0990 1017 1051 1041 072613 1736 1385 1391 1433 1421 104515 1735 1384 1390 1432 1420 1044




04

05

06

07

08

09

1

11

Load

activ

e pow

er (M

W)

6 7 8 9 105Time (min)





50 50


9

10

11

12

13

14

Win

d sp

eed

(ms

ec)

10 12 14 16 18 20 22 248Time (sec)








FSIG

0

05

1

15

2

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

08

09

1

11

12

13

10 12 14 16 18 20 22 248Time (sec)

PMSG DG

10 12 14 16 18 20 22 248Time (sec)

06065

07075

08085

09095

1105

11




119881119862


1 01855 01445 01491 01501 017282 02342 01737 01787 01803 020163 03817 02939 03015 03037 031664 06367 05007 05129 05159 05183




PMSG DG

085

09

095

10 12 14 16 18 20 22 248Time (sec)

FSIG DG

0

01

02

0

01

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

104

106

108

11

112

114

116

118

10 12 14 16 18 20 22 248Time (sec)


V

I

minus15

minus1

minus05

0

05

1

15

Load

V an

d I a

t bus

13

(pu)

1001 1002 1003 1004 100510Time (sec)





PMSG DG

(2)(6)

(1)

(3)

(4) (5)

01234567

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

DFIG DG(1) (6)

(3)(2)(5)(4)

0

1

2

3

4

5

6

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

(2)

FSIG DG

(4)

(1)

(6)(3)

(5)

0

1

2

3

4

5

6TH

D (

)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no














8 Conclusions







No DG(1)(2)

(3)

(4)

0

01

02

03

04

05

06

07Po

wer

loss

es (M

W)




(1)(2)

(3)

(4)

No DG


0

01

02

03

04

05

Pow

er lo

sses

(MW

)



(1)(2)(3)

(4)

No DG

0

01

02

03

04

05

Pow

er lo

sses

(MW

)

















Appendix


1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616




8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s


119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840





119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests



References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of



















Connection bus ofDG


UPF


13 0713 0739 0724 0753 0734

11 0714 0735 0723 0746 0729

9 0715 0731 0722 0739 0725


13 904 729 822 732 878

11 908 748 836 747 881

9 914 769 851 766 888



















0

02

04

06

08

1Vo

ltage

(pu)

05 1 2 25 3 4 50Time (sec)

FSIGDFIG

PMSGSynch


0

02

04

06

0809

1

Volta

ge (p

u)

05 1 2 25 3 4 50Time (sec)

No DGFSIGDFIG

PMSGSynch


0

02

04

06

0809

111

Volta

ge (p

u)

0 1 2 25 3 4 505Time (sec)

1

11

0605

No DGFSIGDFIG

PMSGSynch


DFIGPMSG

09

1

11

12

13

14

DC-

link

volta

ge (p

u)

05 1 15 2 25 3 35 40Time (sec)









interpolation

band-passfilter


low-pass filter


mean filter

Uin

Pst

005 35 Hz( UinUref

)2 S(t)

Calculate Pst by


89

101112131415

Win

d sp

eed

(ms

ec)

11 12 13 14 15 16 17 18 19 21Time (min)




DFIG (UPF) FSIG

040608

112141618

22224

Activ

e pow

er (M

W)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)

DFIG (VC)


DFIG (UPF)

FSIGminus04

minus02

0

02

04

06

08

Reac

tive p

ower

(MVA

R)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)


DFIG (UPF)FSIG

0950955

0960965

0970975

0980985

099

PCC

volta

ge (p

u)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)




FSIG DFIG PMSG119881119862119881

119862UPF

0464 0322 0368 0328












0

005

01

015

02

025

03

Inst

anta

neou

s flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(a) FSIG as a DG

DFIG with UPF mode

0

001

002

003

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

0

001

002

003

004

005

006

Insta

ntan

eous

flic

ker

2 4 6 8 100Time (min)

DFIG with VC mode

(b) DFIG as a DG

0001002003004005006007008009

01

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(c) PMSG as a DG











Synch 119881119862

119881119862


9 0938 0687 0727 0753 0745 048711 1289 0990 1017 1051 1041 072613 1736 1385 1391 1433 1421 104515 1735 1384 1390 1432 1420 1044




04

05

06

07

08

09

1

11

Load

activ

e pow

er (M

W)

6 7 8 9 105Time (min)





50 50


9

10

11

12

13

14

Win

d sp

eed

(ms

ec)

10 12 14 16 18 20 22 248Time (sec)








FSIG

0

05

1

15

2

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

08

09

1

11

12

13

10 12 14 16 18 20 22 248Time (sec)

PMSG DG

10 12 14 16 18 20 22 248Time (sec)

06065

07075

08085

09095

1105

11




119881119862


1 01855 01445 01491 01501 017282 02342 01737 01787 01803 020163 03817 02939 03015 03037 031664 06367 05007 05129 05159 05183




PMSG DG

085

09

095

10 12 14 16 18 20 22 248Time (sec)

FSIG DG

0

01

02

0

01

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

104

106

108

11

112

114

116

118

10 12 14 16 18 20 22 248Time (sec)


V

I

minus15

minus1

minus05

0

05

1

15

Load

V an

d I a

t bus

13

(pu)

1001 1002 1003 1004 100510Time (sec)





PMSG DG

(2)(6)

(1)

(3)

(4) (5)

01234567

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

DFIG DG(1) (6)

(3)(2)(5)(4)

0

1

2

3

4

5

6

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

(2)

FSIG DG

(4)

(1)

(6)(3)

(5)

0

1

2

3

4

5

6TH

D (

)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no














8 Conclusions







No DG(1)(2)

(3)

(4)

0

01

02

03

04

05

06

07Po

wer

loss

es (M

W)




(1)(2)

(3)

(4)

No DG


0

01

02

03

04

05

Pow

er lo

sses

(MW

)



(1)(2)(3)

(4)

No DG

0

01

02

03

04

05

Pow

er lo

sses

(MW

)

















Appendix


1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616




8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s


119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840





119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests



References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















0

02

04

06

08

1Vo

ltage

(pu)

05 1 2 25 3 4 50Time (sec)

FSIGDFIG

PMSGSynch


0

02

04

06

0809

1

Volta

ge (p

u)

05 1 2 25 3 4 50Time (sec)

No DGFSIGDFIG

PMSGSynch


0

02

04

06

0809

111

Volta

ge (p

u)

0 1 2 25 3 4 505Time (sec)

1

11

0605

No DGFSIGDFIG

PMSGSynch


DFIGPMSG

09

1

11

12

13

14

DC-

link

volta

ge (p

u)

05 1 15 2 25 3 35 40Time (sec)









interpolation

band-passfilter


low-pass filter


mean filter

Uin

Pst

005 35 Hz( UinUref

)2 S(t)

Calculate Pst by


89

101112131415

Win

d sp

eed

(ms

ec)

11 12 13 14 15 16 17 18 19 21Time (min)




DFIG (UPF) FSIG

040608

112141618

22224

Activ

e pow

er (M

W)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)

DFIG (VC)


DFIG (UPF)

FSIGminus04

minus02

0

02

04

06

08

Reac

tive p

ower

(MVA

R)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)


DFIG (UPF)FSIG

0950955

0960965

0970975

0980985

099

PCC

volta

ge (p

u)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)




FSIG DFIG PMSG119881119862119881

119862UPF

0464 0322 0368 0328












0

005

01

015

02

025

03

Inst

anta

neou

s flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(a) FSIG as a DG

DFIG with UPF mode

0

001

002

003

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

0

001

002

003

004

005

006

Insta

ntan

eous

flic

ker

2 4 6 8 100Time (min)

DFIG with VC mode

(b) DFIG as a DG

0001002003004005006007008009

01

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(c) PMSG as a DG











Synch 119881119862

119881119862


9 0938 0687 0727 0753 0745 048711 1289 0990 1017 1051 1041 072613 1736 1385 1391 1433 1421 104515 1735 1384 1390 1432 1420 1044




04

05

06

07

08

09

1

11

Load

activ

e pow

er (M

W)

6 7 8 9 105Time (min)





50 50


9

10

11

12

13

14

Win

d sp

eed

(ms

ec)

10 12 14 16 18 20 22 248Time (sec)








FSIG

0

05

1

15

2

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

08

09

1

11

12

13

10 12 14 16 18 20 22 248Time (sec)

PMSG DG

10 12 14 16 18 20 22 248Time (sec)

06065

07075

08085

09095

1105

11




119881119862


1 01855 01445 01491 01501 017282 02342 01737 01787 01803 020163 03817 02939 03015 03037 031664 06367 05007 05129 05159 05183




PMSG DG

085

09

095

10 12 14 16 18 20 22 248Time (sec)

FSIG DG

0

01

02

0

01

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

104

106

108

11

112

114

116

118

10 12 14 16 18 20 22 248Time (sec)


V

I

minus15

minus1

minus05

0

05

1

15

Load

V an

d I a

t bus

13

(pu)

1001 1002 1003 1004 100510Time (sec)





PMSG DG

(2)(6)

(1)

(3)

(4) (5)

01234567

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

DFIG DG(1) (6)

(3)(2)(5)(4)

0

1

2

3

4

5

6

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

(2)

FSIG DG

(4)

(1)

(6)(3)

(5)

0

1

2

3

4

5

6TH

D (

)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no














8 Conclusions







No DG(1)(2)

(3)

(4)

0

01

02

03

04

05

06

07Po

wer

loss

es (M

W)




(1)(2)

(3)

(4)

No DG


0

01

02

03

04

05

Pow

er lo

sses

(MW

)



(1)(2)(3)

(4)

No DG

0

01

02

03

04

05

Pow

er lo

sses

(MW

)

















Appendix


1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616




8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s


119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840





119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests



References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















DFIG (UPF) FSIG

040608

112141618

22224

Activ

e pow

er (M

W)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)

DFIG (VC)


DFIG (UPF)

FSIGminus04

minus02

0

02

04

06

08

Reac

tive p

ower

(MVA

R)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)


DFIG (UPF)FSIG

0950955

0960965

0970975

0980985

099

PCC

volta

ge (p

u)

11 12 13 14 15 16 17 18 19 21Time (min)

PMSG (VC)DFIG (VC)




FSIG DFIG PMSG119881119862119881

119862UPF

0464 0322 0368 0328












0

005

01

015

02

025

03

Inst

anta

neou

s flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(a) FSIG as a DG

DFIG with UPF mode

0

001

002

003

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

0

001

002

003

004

005

006

Insta

ntan

eous

flic

ker

2 4 6 8 100Time (min)

DFIG with VC mode

(b) DFIG as a DG

0001002003004005006007008009

01

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(c) PMSG as a DG











Synch 119881119862

119881119862


9 0938 0687 0727 0753 0745 048711 1289 0990 1017 1051 1041 072613 1736 1385 1391 1433 1421 104515 1735 1384 1390 1432 1420 1044




04

05

06

07

08

09

1

11

Load

activ

e pow

er (M

W)

6 7 8 9 105Time (min)





50 50


9

10

11

12

13

14

Win

d sp

eed

(ms

ec)

10 12 14 16 18 20 22 248Time (sec)








FSIG

0

05

1

15

2

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

08

09

1

11

12

13

10 12 14 16 18 20 22 248Time (sec)

PMSG DG

10 12 14 16 18 20 22 248Time (sec)

06065

07075

08085

09095

1105

11




119881119862


1 01855 01445 01491 01501 017282 02342 01737 01787 01803 020163 03817 02939 03015 03037 031664 06367 05007 05129 05159 05183




PMSG DG

085

09

095

10 12 14 16 18 20 22 248Time (sec)

FSIG DG

0

01

02

0

01

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

104

106

108

11

112

114

116

118

10 12 14 16 18 20 22 248Time (sec)


V

I

minus15

minus1

minus05

0

05

1

15

Load

V an

d I a

t bus

13

(pu)

1001 1002 1003 1004 100510Time (sec)





PMSG DG

(2)(6)

(1)

(3)

(4) (5)

01234567

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

DFIG DG(1) (6)

(3)(2)(5)(4)

0

1

2

3

4

5

6

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

(2)

FSIG DG

(4)

(1)

(6)(3)

(5)

0

1

2

3

4

5

6TH

D (

)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no














8 Conclusions







No DG(1)(2)

(3)

(4)

0

01

02

03

04

05

06

07Po

wer

loss

es (M

W)




(1)(2)

(3)

(4)

No DG


0

01

02

03

04

05

Pow

er lo

sses

(MW

)



(1)(2)(3)

(4)

No DG

0

01

02

03

04

05

Pow

er lo

sses

(MW

)

















Appendix


1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616




8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s


119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840





119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests



References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















0

005

01

015

02

025

03

Inst

anta

neou

s flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(a) FSIG as a DG

DFIG with UPF mode

0

001

002

003

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

0

001

002

003

004

005

006

Insta

ntan

eous

flic

ker

2 4 6 8 100Time (min)

DFIG with VC mode

(b) DFIG as a DG

0001002003004005006007008009

01

Insta

ntan

eous

flic

ker

2 4 6 8 10 0 2 4 6 80Time (min)

(c) PMSG as a DG











Synch 119881119862

119881119862


9 0938 0687 0727 0753 0745 048711 1289 0990 1017 1051 1041 072613 1736 1385 1391 1433 1421 104515 1735 1384 1390 1432 1420 1044




04

05

06

07

08

09

1

11

Load

activ

e pow

er (M

W)

6 7 8 9 105Time (min)





50 50


9

10

11

12

13

14

Win

d sp

eed

(ms

ec)

10 12 14 16 18 20 22 248Time (sec)








FSIG

0

05

1

15

2

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

08

09

1

11

12

13

10 12 14 16 18 20 22 248Time (sec)

PMSG DG

10 12 14 16 18 20 22 248Time (sec)

06065

07075

08085

09095

1105

11




119881119862


1 01855 01445 01491 01501 017282 02342 01737 01787 01803 020163 03817 02939 03015 03037 031664 06367 05007 05129 05159 05183




PMSG DG

085

09

095

10 12 14 16 18 20 22 248Time (sec)

FSIG DG

0

01

02

0

01

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

104

106

108

11

112

114

116

118

10 12 14 16 18 20 22 248Time (sec)


V

I

minus15

minus1

minus05

0

05

1

15

Load

V an

d I a

t bus

13

(pu)

1001 1002 1003 1004 100510Time (sec)





PMSG DG

(2)(6)

(1)

(3)

(4) (5)

01234567

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

DFIG DG(1) (6)

(3)(2)(5)(4)

0

1

2

3

4

5

6

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

(2)

FSIG DG

(4)

(1)

(6)(3)

(5)

0

1

2

3

4

5

6TH

D (

)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no














8 Conclusions







No DG(1)(2)

(3)

(4)

0

01

02

03

04

05

06

07Po

wer

loss

es (M

W)




(1)(2)

(3)

(4)

No DG


0

01

02

03

04

05

Pow

er lo

sses

(MW

)



(1)(2)(3)

(4)

No DG

0

01

02

03

04

05

Pow

er lo

sses

(MW

)

















Appendix


1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616




8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s


119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840





119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests



References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of




















Synch 119881119862

119881119862


9 0938 0687 0727 0753 0745 048711 1289 0990 1017 1051 1041 072613 1736 1385 1391 1433 1421 104515 1735 1384 1390 1432 1420 1044




04

05

06

07

08

09

1

11

Load

activ

e pow

er (M

W)

6 7 8 9 105Time (min)





50 50


9

10

11

12

13

14

Win

d sp

eed

(ms

ec)

10 12 14 16 18 20 22 248Time (sec)








FSIG

0

05

1

15

2

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

08

09

1

11

12

13

10 12 14 16 18 20 22 248Time (sec)

PMSG DG

10 12 14 16 18 20 22 248Time (sec)

06065

07075

08085

09095

1105

11




119881119862


1 01855 01445 01491 01501 017282 02342 01737 01787 01803 020163 03817 02939 03015 03037 031664 06367 05007 05129 05159 05183




PMSG DG

085

09

095

10 12 14 16 18 20 22 248Time (sec)

FSIG DG

0

01

02

0

01

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

104

106

108

11

112

114

116

118

10 12 14 16 18 20 22 248Time (sec)


V

I

minus15

minus1

minus05

0

05

1

15

Load

V an

d I a

t bus

13

(pu)

1001 1002 1003 1004 100510Time (sec)





PMSG DG

(2)(6)

(1)

(3)

(4) (5)

01234567

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

DFIG DG(1) (6)

(3)(2)(5)(4)

0

1

2

3

4

5

6

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

(2)

FSIG DG

(4)

(1)

(6)(3)

(5)

0

1

2

3

4

5

6TH

D (

)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no














8 Conclusions







No DG(1)(2)

(3)

(4)

0

01

02

03

04

05

06

07Po

wer

loss

es (M

W)




(1)(2)

(3)

(4)

No DG


0

01

02

03

04

05

Pow

er lo

sses

(MW

)



(1)(2)(3)

(4)

No DG

0

01

02

03

04

05

Pow

er lo

sses

(MW

)

















Appendix


1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616




8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s


119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840





119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests



References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















FSIG

0

05

1

15

2

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

08

09

1

11

12

13

10 12 14 16 18 20 22 248Time (sec)

PMSG DG

10 12 14 16 18 20 22 248Time (sec)

06065

07075

08085

09095

1105

11




119881119862


1 01855 01445 01491 01501 017282 02342 01737 01787 01803 020163 03817 02939 03015 03037 031664 06367 05007 05129 05159 05183




PMSG DG

085

09

095

10 12 14 16 18 20 22 248Time (sec)

FSIG DG

0

01

02

0

01

10 12 14 16 18 20 22 248Time (sec)

DFIG DG

104

106

108

11

112

114

116

118

10 12 14 16 18 20 22 248Time (sec)


V

I

minus15

minus1

minus05

0

05

1

15

Load

V an

d I a

t bus

13

(pu)

1001 1002 1003 1004 100510Time (sec)





PMSG DG

(2)(6)

(1)

(3)

(4) (5)

01234567

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

DFIG DG(1) (6)

(3)(2)(5)(4)

0

1

2

3

4

5

6

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

(2)

FSIG DG

(4)

(1)

(6)(3)

(5)

0

1

2

3

4

5

6TH

D (

)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no














8 Conclusions







No DG(1)(2)

(3)

(4)

0

01

02

03

04

05

06

07Po

wer

loss

es (M

W)




(1)(2)

(3)

(4)

No DG


0

01

02

03

04

05

Pow

er lo

sses

(MW

)



(1)(2)(3)

(4)

No DG

0

01

02

03

04

05

Pow

er lo

sses

(MW

)

















Appendix


1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616




8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s


119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840





119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests



References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















PMSG DG

(2)(6)

(1)

(3)

(4) (5)

01234567

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

DFIG DG(1) (6)

(3)(2)(5)(4)

0

1

2

3

4

5

6

THD

()

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no

(2)

FSIG DG

(4)

(1)

(6)(3)

(5)

0

1

2

3

4

5

6TH

D (

)

2 3 4 5 6 7 8 9 10 11 12 13 14 151Bus no














8 Conclusions







No DG(1)(2)

(3)

(4)

0

01

02

03

04

05

06

07Po

wer

loss

es (M

W)




(1)(2)

(3)

(4)

No DG


0

01

02

03

04

05

Pow

er lo

sses

(MW

)



(1)(2)(3)

(4)

No DG

0

01

02

03

04

05

Pow

er lo

sses

(MW

)

















Appendix


1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616




8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s


119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840





119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests



References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of



















No DG(1)(2)

(3)

(4)

0

01

02

03

04

05

06

07Po

wer

loss

es (M

W)




(1)(2)

(3)

(4)

No DG


0

01

02

03

04

05

Pow

er lo

sses

(MW

)



(1)(2)(3)

(4)

No DG

0

01

02

03

04

05

Pow

er lo

sses

(MW

)

















Appendix


1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616




8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s


119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840





119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests



References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of



















Appendix


1198851-2 01114 + 119895033401198852-3 01310 + 119895039301198853-4 01572 + 119895047161198854-5 01048 + 119895031441198855-6 00590 + 119895017691198856-7 00236 + 119895007071198857-8 00707 + 119895021221198858-9 00354 + 119895010611198859-10 00482 + 1198950144611988510-11 00844 + 1198950253011988511-12 00482 + 1198950144611988512-13 00985 + 1198950295411988513-14 01231 + 1198950369311988514-15 01539 + 11989504616




8MVA 6611 kV Δ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


22MVA 110575 kVΔ119884119892

1198771= 1198772= 0002 pu

1198831= 1198832= 002 pu

119877119898= 119883119898= 500 pu


119877119904= 0016 pu119871119897119904= 0060 pu1198771015840

119903= 0015 pu1198711015840

119897119903= 0060 pu119871119898= 350 pu119867119892= 0700 s119867119879= 4000 s


119877119904= 0023 pu119871119897119904= 0180 pu1198771015840

119903= 0016 pu1198711015840





119883119889= 1400 pu119883119902= 1372 pu1198831015840

119889= 0231 pu1198831015840

119902= 0800 pu11988310158401015840

119889= 0118 pu11988310158401015840

119902= 0118 pu119883119897= 0050 pu119877119886= 000014 pu1198791015840

119889119900= 5500 s

1198791015840

119902119900= 1250 s11987910158401015840

119889119900= 0050 s

11987910158401015840

119902119900= 0190 s119867 = 15 s

Competing Interests



References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















References































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of





















FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of

















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