1

Transient Stability Method to D t i M i I t itt tDetermine Maximum Intermittent Power Plant Penetration to SmallPower Plant Penetration to Small

Island Isolated System

S.Sasmono, .J.A Alwie, A.Wijaya, N.HariyantoIEEE M b #92352179 d @ d i idIEEE Member #92352179, udar@quadranenergi.id

Quadran Energi RekayasaJln Gelap Nyawang 4 Bandung, Indonesia

http //www quadranenergi id/http://www.quadranenergi.id/

Structure of Presentation2

Structure of Presentation

• IntroductionM d lli• Modelling

• Case Study– Solar PV Farm Only– Solar PV Farm + Batteries– Solar PV Farm + Batteries

• Conclusion

Introduction3

Introductionhi l i i ll i f i l d ll i l d h f h• Archipelagic countries generally consist of isolated small islands where a part of such

islands have inhabitants even in large numbers• The electrical power system on such small islands is isolated (not connected to main

grid in main land) and use middle voltage for electricity distribution.• Limited primary energy on such isolated small islands causes renewable energy to be

one of favorite the primary energy options for electricity generation• One of favorite energy primary type especially in tropical areas is solar energy• Solar energy convert to electricity through Solar PV Farm as one of popular

implemented technologyp gy• Solar PV Farm are non-dispatchable and intermittent power plant.• The maximum capacity of such intermittent power plant should be determined in

planning phase to maintain perform of middle voltage electricity distribution systemplanning phase to maintain perform of middle voltage electricity distribution system.

Modelling4

Modellingl ( ) f

• The system frequency serves as a Single Line Diagram (SLD) of

connecting model in 20 kV Electricity System

controller between load and generation.

• If the generation exceeds the load then the frequency will increase beyond its nominal frequency and vice versa.

• Frequency control is carried out through the control of the active power flow by regulating the governor.

• The system frequency change is given by following equation:

Modelling (2)5

Modelling (2)• Where the symbol in equation are following :y q g

– ΔL is magnitude of overload, – D is load damping constant applicable to area load,D is load damping constant applicable to area load, – M representing total rotational inertia of the generators in

the area. • Equations show that the system frequency change of the

nominal frequency is affected by the inertia of the system. • Solar PV Farm is power plant without inertia• Thus, injected Solar PV to grid has the potential to cause

system frequency to become unstable during intermittent and disturbance conditions.

Modelling (3)6

Modelling (3)

• The propose method to determine the maximum capacity ofsolar PV can injected to system is using the transient stability ofsolar PV can injected to system is using the transient stability ofthe system during disturbance and intermittent conditionwhen the system already receive Solar PV Farm

• The capacity where the system can keep its performance duringdisturbance/intermittent condition will be maximum capacity.

• The transient stability will be carried out after load flow andshort circuit analysis find no problem in system performance

Case Study7

yDefinition

• Case study carried out in one of small island inIndonesia which have used 20 kV system in itsdi ib i kdistribution network

• The Solar PV Farm will be connected to system in 2019• Since peak load demand forecasting will be 43.68 MW

then the almost 10% of peak load is 4.8 MW ascapacity of Solar PV Farm which is planning injected tosystem

• Simulations carried out in “must run”, just to meettechnical considerations

Case Study8

Case StudyModelling of System

PLTG PT. Wahana2 x 0,7 MW

PLTD/G M a K4 x 2,54 MW

PLTD B&W2 x 1,03 MW

PLTD Kutilang Paksi Mas7 x 0,5 MW

PLTMG PT. Max Power III2 X 3 MW

PLTG WARTSILA5,5 + 3,8MW

PLTD/G MAN B&W2 x 2,77 MW

PLTD MAN/G9V 1 x 1,46 MW

PLTMG PT. ATAMORA 4 x 0,58 MW

PLTD Agreko6 x 0,83 MW

Feed

er 1

Feed

er 3

Feed

er 4

Feed

er 5

Feed

er 6

Feed

er 8

Feed

er 2

Feed

er 7

Feed

er 9

Feed

er 10

LBS-M SIMPANG INTRACA

PLTU PT IDEC AWI I 5 MW

GH IndoorPT.KMS

PLTMG PT. Max Power I2 MW

PLTMG PT Sewatama II

4 X 1 MW

PLTS 4,8 MW

PLTG Perusda2 x 4,5 MW

PLTMG PT. Max Power I

2 x 2 MW

PLTMG Perusda2 x 1,5 MW

PLTMG PT. Max Power IV

3 MW

PLTU PT IDEC AWI II2 MW

PLTMG PT. Max Power II

2 x 3 MW

N t

PLTMG PT. Sewatama I PLTMG Kerta Bumi

Note• PLTD = Diesel Power Plant• PLTG/PLTMG = Gas Engine Power

Plant• PLTU = Coal Fire Power Plant

PLTS S l PV F2 x 1,4 MW

PLTMG PT.Arena Maju Bersama3 x 1 MW

Teknindo4 x 0,45 MW

• PLTS = Solar PV Farm

Case Study9

Case StudyModel Validation

Measurement The Model isMeasurement21 Oct 2016, 14.00 Simulation ResultsThe Model is

valid

Case Study 10

yLoad flow before Solar PV Farm Injected to system

Note1. Load = 43.68 MW2. Load in Feeder 4 = 12.46 MW3. End-Voltage = 16.8 kV (0.84 p.u.)4 Th i l d i k4. There is no overload in system network

Case Study 11

yLoad flow after Solar PV Farm Injected to system

Note1. Supply from PLN to feeder 4, decrease to

7.4 MW2. Voltage at the end of feeder 4 is improve

(from 16.8 kV to 17.5 kV)3. There is no overload in system network

Case Study12

yShort Circuit Analysis

BUSBefore Interconnection 2019 After Interconnection 2019Ik” ip Ib Ik Ik” ip Ib IkkA kA kA kA kA kA kA kAkA kA kA kA kA kA kA kA

Gunung Belah 7.50 18.64 6.62 7.50 7.93 19.55 6.94 7.76

Point of Interconnection

(feeder)1.30 2.63 1.30 1.30 1.50 3.13 1.50 1.50

( )PV Farm MV side (20

kV)- - - - 1.50 3.12 1.50 1.50

The level of breaking capacity in 20 kV system in Indonesia have been 16 kV

Case Study13

yTransient Stability Analysis

Case Study14

yTransient Simulation (4.8 MW)

Loss of PV Generation from 100% to 0% instantly

Case StudyyTransient Simulation (4.8 MW)

Intermittent Condition Due to Cloud Movement Power Output decrease from 100% to 25%from 100% to 25%

4.8 MW (6 MWp) Solar PV Farm is not acceptable.The perform of system become worst during disturbance and/or

intermittent conditionintermittent condition

Case Study16

ySolution Model

Si h iff f i b• Since the stiffness of system is about3.87 MW/Hz then if the systemfrequency reduction during intermittent

diti i t t d t t t h thcondition is targeted not to touch theUFR setting for automatic loadshedding phase 1 (49.60 Hz), then themaximum capacity of Solar PV can bemaximum capacity of Solar PV can beconnected to the system withoutdisturbance performance of the systemshould be smaller than 1 55 MWshould be smaller than 1.55 MW.

• It will be only smaller than 0.4 Hzsystem frequency drop from its nominalfrequency Thus in the secondfrequency. Thus, in the secondsimulation, Solar PV capacity can beconnected to system 1.5 MW orequivalent to 1.875 MWp.equivalent to 1.875 MWp.

Case StudyCase StudyTransient Simulation (1.5 MW/1.875 MWp)

Loss of PV Generation from 100% to 0% instantly

Intermittent condition due to cloud movement cover Solar PV panel in 2 s

1.5 MW (1.875 MWp) Solar PV Farm is acceptable.The perform of system can keep in good condition during disturbance

and/or intermittent conditionand/or intermittent condition

Case StudyCase StudyTransient Simulation (Solar PV Farm 4.8 MW/6 MWp + Batteries 1 MWh/142.85 Ah )

Loss of PV Generation from 100% to 0% instantly

Intermittent condition due to cloud movement cover Solar PV panel in 2 s

4.8 MW (6 MWp) Solar PV Farm + Batteries 1 MWh/142.85 Ah is acceptable.

The perform of system can keep in good condition during disturbanceThe perform of system can keep in good condition during disturbance and/or intermittent condition

Discussion and ConclusionDiscussion and Conclusion• In the archipelagic country that lies around the equatorial line, cloudIn the archipelagic country that lies around the equatorial line, cloud

formation is relatively rapid. Such condition leads to the possibility ofrepetitive intermittent conditions every day. Transient stability methodwith system frequency as a criterion can help to understand performancewith system frequency as a criterion can help to understand performanceof the system during the intermittent condition.

• to strengthen the conclusions of system performance as the basis fordetermining the maximum capacity of Solar PV that can be connected tosystem, then the system frequency dynamics in case of Solar PV pull outfrom the system suddenly need to consider.

• The combination of both simulations helps assure conclusions ofmaximum Solar PV capacity that the system can accept without causingany system performance disruptionany system performance disruption.

• Adding batteries can keep installed capacity of Solar PV Farm injected tosystem

ReferencesReferences and About Quadran Energi Rekayasa

1. Indonesia Presidential Decree No 22/2017 on National Energy Planning, 2017.

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Station based on the “Box” Set Robust Optimization”, The International Conference on Advanced System Automation and Protection, 2011, pp 507-511.

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Consultant in Electrical Power SystemQuadran Energi Rekayasa was founded by thosewho had studied in the Laboratory of ElectricalPower and Distribution Systems, School ofElectrical Engineering and Informatics inMethod to Evaluate Maximum Capacity of Photovoltaic

Integration Considering Network Topology Reconfiguration”, IEEE Power and Energy General Meeting, 2016, pp 1-5.

4. Tao Ding, Yu Kou, Yongheng Yang, Yiyang Zhang, Huan Yan, Blaabjerg, Frede, “Evaluating Maximum Photovoltaic

Electrical Engineering and Informatics inBandung Institute of Technology.Quadran Energi Rekayasa establish since 2014.Quadran Energi Rekayasa based in Bandung,

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