power qualkity analysis

7/27/2019 Power Qualkity Analysis

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Advanced Power Quality

Analysis

Using PCs to Solve

Harmonic Problems

Our Circuit

Transmission Line

Source

21

5

4

3


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Our

Transmission

Line....

(-X) (+X)

50.0'

77.5'

98.5'

(+Y)

1.5'

12.9'12.9'

19.6' 19.6'

LINE PHYSICAL CONFIGURATION

TRANSMISSION LINE:

500 kV50 miles

(2) - "CHUKAR" - 1,780 MCM 84/19 ACSR per phase

SS

A

B

C

Our Goal......Our goal is to modify the power system to

reduce voltage and current distortion.

Later we will do this by converting the

power factor correction capacitors into tuned

filters.


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Define the Harmonic Source Library

Define Transmission Lines


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Create Transformer Records

text

Create the Feeders........


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Create the Utility Source........

text

Create the Motor Contribution Source........


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Specify the Harmonic Sources........

Specify the Capacitor Bank


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Execute Studies........

For most cases, four studies will be executed using the power

system configuration defined by you, typically in this

sequence:

1. Harmonic Load Flow.

2. Frequency Scan for Resonance.

3. Distortion Calculations (current and voltage).

Harmonic Load Flow


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Execute the Frequency ScanFor Resonance Study........

The impedance shown in the calculation is the

Thevenin impedance looking into the selected bus

to ground.


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View Graphical Output of the Voltage

Distortion


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View Graphical Output of the Current

Distortion


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Make System Improvements........

The next phase of the tutorial deals with modifying the

power system to compensate for the harmonic distortion

that the reports and graphics indicate.

The capacitors at Buses 4 and 5 will be tuned into

single-tuned filters.

Tune the Capacitor at Bus 4 into a Single-

Tuned Filter


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Tune the Bus 5 Capacitor Bank into a

Single-tuned Filter


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Comparing Results........

Now that the filters have been designed and applied

to the system, the harmonic studies must be re-

executed to determine how the changes have affected

the system resonance and distortion.


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Compare the Frequency Scan Plots at Bus 4


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Compare the Current Distortion Plots at

Branches 2-3 and 3-4


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Compare the Voltage Distortion Plots

at Bus 3


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Have a nice day!


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1


Analysis

Using PCs to Solve

Harmonic ProblemsSection X&A

Basic Tools and Methods ofHarmonic Analysis

We will

Analyze the current and voltage

wave forms using the Fourier

SIN or COS method


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Basic Tools and Methods of Harmonic Analysis.

Harmonic Analysis Techniques Available:

1. Symmetrical Components

Limited to balanced 3 phase systems

with balanced or unbalanced events

2. Eigen Value Method

Can be applied to four conductor,

DC or multi-phase systems

Basic Tools and Methods of Harmonic Analysis.

HI_WAVE uses

the Eigen Value

Method.


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Basics of a Computer Analysis

X. Prepare a One-Line Diagram

X1. Define transmission line.

X2. Define feeders.

X3. Define capacitors and harmonic sources.

X4. Define source and transformers.

Basics of a Computer Analysis.

A. Define Component Library

A1. Define feeder library.

A2. Define harmonic source library.

A3. Define transmission line library.


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B. Define System Topology

(Branch records that connect buses)

B1. Create the transmission lines.

B2. Create the transformers.

B3. Create the feeders.

B4. Create the Utility sources.

B5. Create motor contribution sources.


C. Define System Topology

(Loads and Devices at Buses)

C1. Specify the source bus.

C2. Specify the harmonic sources.

C3. Specify the capacitor banks/filters.


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D. Execute Studies

D1. Execute demand load analysis (if reqd).

D 2. Execute harmonic load flow analysis.

D 3. Execute freq. scan for system resonance.

D 4. Execute voltage and current dist. calcs.


E. Evaluate and Modify System

E1. Make system improvements.

E2. Comparing results.


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X1. Our Transmission Line

Transmission Line

Source

21

5

4

3

X1. Our

Transmission

Line....

(-X) (+X)

50.0'

77.5'

98.5'

(+Y)

1.5'

12.9'12.9'

19.6' 19.6'

LINE PHYSICAL CONFIGURATION

TRANSMISSION LINE:

500 kV50 miles(2) - "CHUKAR" - 1,780 MCM 84/19 ACSR per phase

SS

A

B

C


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Cable or Transmission Line Modeling

In a low voltage system non-linear modeling is

usually not required.

Cables and lines can be modeled by Cascaded PI

modeling or Distributed Equivalent PI modeling.

The Distributed Equivalent PI method is used in

HI_WAVE for increased accuracy.

HI_WAVE allows for modeling of line charging,series compensation, and shunt compensation.

X2. Our Feeders....Feeder from BUS 3 to 4:Feeder from BUS 3 to 5:

250 MCM - Copper - XLP - 15 kV rated cabl1000 circuit feetin 3.5 inch non-metallic conduit

21

5

4

3

Feeder

Feeder


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X3. Our Capacitor Banks and

Harmonic Source....

21

5

4

3HarmonicSource

Capacitor Bank #5

Capacitor Bank #4

X3. Our

Capacitor

Banks

and

Harmonic

Source....

Capacitor Bank - BUS 5:

Capacitor Bank - BUS 4:

Harmonic Source:

400 kVAR13.8 kV ratedWYE Connected

1000 kVAR13.8 kV ratedWYE connected

1000 HP (kVA) VFD driveMeasured CURRENT DISTORTIONper SKM "TUTORIAL"

5th = 37.6%7th = 12.55%11th = 7.11%13th = 3.35%17th = 2.93%19th = 1.67%


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X4. Our Utility Source and

Transformers....

Z = 8%

X/R = 10Fault Duty1000 MVA

21

5

4

3

Source:

500 kV1000 mVA (Avail. short ckt.)X/R = 30

Transformer:

500 kV Delta primary13.8 kV WYE (grounded) secondary5000/5500 kVA 0A/FAZ = 8%X/R = 10

Our Goal......Our goal is to modify the power system to

reduce voltage and current distortion.

Later we will do this by converting the

power factor correction capacitors into tuned

filters.

Let's go to the computer lab.


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About HI_WAVE.....

Minimum System Operation requires:

HI_WAVE 386 needs EXTENDED memory

Free ram must be greater than 575 k

MEM = 2 megs or greater of XMS Memory

5 megs of hard drive to install program

To start HI_WAVE


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Press F1, and the HI_WAVE Project Manager will list all of the

available project files. Select the TUTORIAL project.

Press F5: Execute, and the HI_WAVE Main Menu will appear


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Press F2: Libraries. Press Enter to access the HI_WAVE library

A1. Define Feeder Library........Press F1: Feeder & Raceway;

Make sure the menu data matches the menu below.


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Press F1: Fetch to access the cable data

To enter the non-linear data required for this project, press F9:

Frequency Dependent, and the window shown below will appear


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To view the existing model, position the marker bar over the

250 EXISTING and press Enter

Resistivity = 1/volume conductivity

Relative Permeability is a relationship between

magnetic induction and magnetic force

Relative Permittivity is related to the dielectric

constant


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Select F10:Continue and make sure the Menu data

matches the data below

Press Esc-Abort to return to the menu below


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Press Esc-Abort until you return to the menu below

Press F5: Harmonic Sources

A2. Define the Harmonic Source Library

From the HI_Wave

Libraries menu select

F5:Harmonic Sources


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Press Enter then press F5: Enter/Edit Detailed Model

Load Types

Constant Impedance = incandescent lights

or resistance heaters - loads that vary with

the square of the voltage applied.

Constant kVA = motors, constant wattage

ballast's - loads that attempt to remain at

the same kW input regardless of voltage

applied.

Constant Current = load whose current is

affected by fluctuations in bus voltage

phase angle.


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Modeling The Harmonic Source

Six pulse (Classical method)

Pros: Can model commutation reactance and phase angles.

Cons: Cannot accurately model ripples of the wave form.

Six pulse (Dobinson method)

Pros: Allows ripples in the direct current to be modeled.

Pros: Particularly accurate for 5th and 7th harmonics .

Cons: Cannot model commutation reactance and phase angles.


Six pulse (Graham-Schonholzer / G-S method)

Pros: Models direct current and higher order

harmonics.

Six pulse (Rice FFT method)

Pros: Samples the direct current wave form

considering commutation and firing angles.

Pros: Produces an accurate description of entirecurve in time domain.


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Twelve pulse (Classical method)

Twelve pulse (Dobinson method)

Twelve pulse (Graham-Schonholzer method)

Twelve pulse (Rice FFT method)

Twelve pulse converters are modeled as two six pulse units

with a 30 degree phase shift.


kVA field is the converter kVA nameplate rating.

PF must be estimated since it changes with load.

Max Order is up to your discretion.

Alpha data field is up to your discretion (0-90)

Lower value implies more power to the load.

Xc usually is reactance in p.u. of the series reactor.

L(mh) is the motor load converted to an inductance.


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When the data for the first screen is checked, use F2: Next Page to

move to screen two.

When all the data has been checked, press F1: Return with Data

and then F1: Save to exit the screen and save the source in the

library.

The source name will appear on

the left-hand side of the screen

at the bottom of the source list

as shown below.


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When the harmonic source has been created and saved, press F10:

Exit until you return to the HI_WAVE Libraries Menu.

A3. Define the Transmission Line Library........

From the HI_WAVE

Libraries Menu, select F8:

Transmission Lines and

the Transmission Line

Library shown will appear.


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Press Enter This library allows you to enter detailed

frequency dependent transmission line data.

After the data has been checked, press F10: Exit to return tothe HI Wave library menu.


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Goto Section B


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Analysis

Using PCs to Solve

Harmonic ProblemsSection B&C

B1. Create the Transmission Line.....

Return to the Main menu. Press F10: Exit


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Press F1: Branch Records to obtain the menu SIMILAR to the

menu below. Hit F9 to turn scan on.

text

On the left side of the menu, highlight the record line that says

From Bus 1 (Utility) to Bus 2 (TRX Pri). Then press Return to get

the Menu as shown below:


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When all of the above data is correct, press F9: Freq. Dep. Ln.

This will call up a list of the non-linear transmission line models in

the transmission line library, as illustrated below.

Position the marker bar over the Transmission Line ID name, and

press Enter. This will automatically enter the model into the

branch record.


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The name of the selected model Transmission will appear in the

Frequency Dep. Model data field as shown in the figure below.

This is important!

The transmission line branch record is now complete and may be

saved by pressing F1: Save.

Press F10: Exit to return to the left hand portion of the screen.

Note that the branch name is now visible in this portion of the

screen, verifying that the branch record has been created and

saved.


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B2. Create the Transformer........

Transformer Modeling

Program considers non-linearity caused by over

excitation or overloading.

Transformer connections and phase shifting are modeled.

Phase shifting is important when more than one source

of harmonics exists.

Program considers impedance versus frequency using a

Laplace transformation. This modeling is automatic.

Consider using EXISTING vs. DESIGN when modeling

transformers.


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The transformer branch record is now complete. Press F1: Save

to save the record and F10: Exit to return to the left-hand

window of the Branch Record Editor.

B3. Create the Feeders........

On the left side of the menu, highlight the record line that says FromBus 3 (TRX Sec) to Bus 4 (Filter). Then press Return to get the

Menu as shown below.


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Press F1: Save to save the record and F10: Exit to return to the

left-hand window of the Branch Record Editor.

On the left side of the menu, highlight the record line that says

From Bus 3 (TRX Sec) to Bus 5 (Harm Source). Then press

Return to get the Menu as shown below.

text


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Press F1: Save to save the record and F10: Exit to return

to the left-hand window of the Branch Record Editor.

B4. Create the Utility Source........

On the left side of the menu, highlight the record line that

says From C UTILITY to 1 UTILITY. Then press


Note that the fault duty contribution record is displayed on a

line different than the specified branch, and is identified

with a "C" to the left of contribution type, as shown below.

For the purposes of this tutorial, a utility fault duty will be

defined for Bus 1, and the harmonic source at Bus 5 will bespecified as an induction motor contribution.


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Press F10: Exit to return to the Branch Record Editor.

text

B5. Create the Motor Contribution Source........

On the left side of the menu, highlight the record line that

says From C MOTOR to 5 HARM SOURC. Then press


Note that the fault duty contribution record is displayed on a

line different than the specified branch, and is identified

with a "C" to the left of contribution type, as shown below.


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We define the induction motor contribution record in the same

manner as the utility fault duty, specifying the contribution data

as shown below. Press F10: Exit to return to the Branch RecordEditor

Notes On Inputting Data:

Co-generation - Do not model as a source bus, use the

special co-generator model.

Generators operating in parallel with the Utility may be

defined as special bus generation load in the bus records.


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To specify a source bus, press F7: Source Bus from the figure

above, and the Define Source Bus Records window will appear as

shown below.

Specify Bus 1 as the source bus, as shown

above. When the source bus has been

specified, press F10: Exit to return to the

list of bus records on the left side of the

screen.


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C2. Specify the Harmonic Sources........

To specify the harmonic source at Bus 5, position the marker barover Bus 5, and press F9: Load/Filter. The Harmonic Filter Data

screen shown below will appear. Press Enter to access the screen.

When the screen is accessed, a harmonic source may be selected by

pressing F5: Harmonic Source Library; the list of sources in the

harmonic source library will appear as shown below


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Position the marker bar on the Tutorial Source and press Enter to

select it. HI_WAVE returns to the Harmonic Source/Filter Data

screen, automatically inserting the source into the bus record. To

verify that the source has been added to the bus record, make surethat the source name appears in the Library Source data field.

Specify a 1000 kVA rating in the kVA data field, as illustrated

below.

C3. Specify the Capacitor Bank and Filter........

While you are in this window, the capacitor bank data maybe defined. Press F6: Filter or Capacitor to access the

Interactive Designer for Filters and Capacitor Banks

window shown below.


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Enter the capacitor data for Bus 5 shown below.

Press F6: Calculate Filter or Capacitor & Return Data;

HI_WAVE calculates the capacitor data, inserts the data into the

branch record, and returns control to the Harmonic Filter Datawindow, as shown below.


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Press F1: Save to save the capacitor data with

Bus 5 and return to the list of bus records on the

left where the capacitor data for Bus 4 will now

be specified.

Position the marker bar over Bus 4 and press Enter to access the

Harmonic Source/Filter Data entry window shown below. Make

sure that Bus 4 has been selected by checking the bus record

number in the upper left-hand portion of this window.


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Press F6: Filter or Capacitor to access the Filter/Capacitor design

window. Enter the capacitor data shown below.

When this data has been entered, press F6: Calculate Filter or

Capacitor & Return Data. HI_WAVE will calculate the

capacitor data, insert the data into the bus record, and return controlto the Harmonic Filter Data window, as shown below.


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Bus 4 is now defined and the bus records are complete. Press F1:

Save to save the filter data, and press F10: Exit until the

HI_WAVE Main Menu appears. You have now configured the

network topology for the entire tutorial project, and can begin to

execute HI_WAVE studies to scan the system for resonance and

harmonic distortion.


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Analysis

Using PCs to Solve

Harmonic ProblemsSection D1-D2-D3

D. Execute Studies........

You have now configured the network

topology for the entire tutorial project, and can

begin to execute HI_WAVE studies to scan the

system for resonance and harmonic distortion.


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For most cases, four studies will be executed using thepower system configuration defined by you, typically in this

sequence:

1. Demand Load Analysis.

2. Harmonic Load Flow.

3. Frequency Scan for Resonance.

4. Distortion Calculations (current and voltage).


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In the case of the Tutorial, executing a Demand Load Analysis is

not necessary. The reasons for executing the studies in this

sequence will be explained during the course of the analysis

sections.

D1. Execute Demand Load Analysis........

Normally, you would have specified end use load and/or

special bus loads in a project in which case a Demand Load

Analysis would be executed.

Since the only loads in this project are harmonic sources, a

Demand Load Analysis is not necessary; the Harmonic Load

Flow Program models all harmonic source load data. Had you

specified end use loads or special bus loads, the Demand Load

Analysis would have been the first study executed.


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Demand Load Analysis

Connected Load - Sum of:

End Use Loads + Loads on feeders to that bus.

Demand Load - Sum of:

End Use Loads + Loads on feeders to that bus,

except that diversity factors are applied at EACH bus.

Design Load - Sum of:

DEMAND Loads times applicable code or designer safetyfactors.

Demand load analysis does not allow loops, only radial

feeders.

If all the loads are entered as special bus loads,

there is no need to run the DLA.

The Harmonic Load Analysis allows looped feeders.


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D2. Execute Harmonic Load Flow Analysis........

From the main menu select F8: Execute Studies, and the

Harmonic Investigation Studies screen will appear.

Select F2: Harmonic Load Flow from this screen, and the

report name window will be called up.

Enter the report name as shown below.


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Harmonic Load Flow Study

Does not evaluate feeder or transformer capacity.

Automatically includes all passive elements

including filters.

Harmonic load flow can have looped system.

Press F1: Continue, and enter title lines for the study as

shown below or any text you like.


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After the title lines have been entered, press F1: Continue,and the HI_WAVE Load Flow Criteria screen will appear.

In this screen, you set the criteria for the solution method, the

system modeling requirements and the solution criteria.

These criterion categories should be reviewed to discover the

available options.

For the purposes of the tutorial, enter the criteria options

shown below.

Press F1: Continue, and HI_WAVE will execute the

harmonic load flow study.


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Review the Harmonic Load Flow Report

After executing the harmonic load flow study, the

program will return to the HI_WAVE Main Menu.

To review the harmonic load flow report, select

F7: Edit Scan Files. Enter the harmonic load

report file name in response to the HI_WAVE

prompt, as shown below or select F3: to view all

available files.

Press F1: Continue, and the report shown below will be

displayed.

Important Features of the Harmonic Load Flow Report


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P A S S I V E F I L T E R D A T A

BUS VOLTAGE FILTER PARAMETERS FILTER LOAD

R JWL JWC KVA PF

==============================================================================

4 FILTER 13800.

+ sequ: .00 .00 190.44 1000.0 .0000

0 sequ: .00 .00 .00

5 HARM SOURC 13800.

+ sequ: .00 .00 476.10 400.0 .0000

0 sequ: .00 .00 .00

F E E D E R D A T A

FEEDER FROM FEEDER TO QTY VOLTS LENGTH FEEDER DESCRIPTION

NO NAME NO NAME /PH L-L SIZE TYPE DUCT INSUL

==============================================================================

1 UTILITY 2 TRX PRI 1 500000. 50. MI

IMPEDANCE: .0300000 + J .0900000 PER UNIT

B/2: .004000 PER UNIT % SERIES COMP: .0

TO SHUNT(KVAR): 200. FROM SHUNT(KVAR): 200.

3 TRX SEC 4 FILTER 1 13800. 1000. FT 250 C N XLP

IMPEDANCE: .0891 + J .0396 OHMS/M FEET

3 TRX SEC 5 HARM SOURC 1 13800. 1000. FT 250 C N XLP

IMPEDANCE: .0891 + J .0396 OHMS/M FEET STATUS: EXISTING

==============================================================================

SOURCE BUS THEVENIN EQUIVALENT IMPEDANCE: 8.329 + J 249.861 OHMS

Calculated From Largest 3-PHASE Fault Contribution

==============================================================================


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T R A N S F O R M E R D A T A

PRIMARY RECORD VOLTS PRI * SECONDARY RECORD VOLTS SEC NOMINAL

NO NAME L-L FLA NO NAME L-L FLA KVA

==============================================================================

2 TRX PRI 500000. 6. 3 TRX SEC 13800. 209. 5000.

IMPEDANCE: .7960 + J 7.9603 PERCENT

B R A N C H L O A D D A T A

=============================================================================F R O M / T O BR. CONSTANT KVA CONSTANT Z CONSTANT I FLOW

B U S / B U S TYPE KVA %PF KVA %PF KVA %PF DIR.

=============================================================================

The Harmonic Load Flow Program reports end use load data

under the Branch Load Data heading. Since there is no such

data in the Tutorial project, this heading is empty.


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B U S S P E C I A L S T U D Y D A T A

==============================================================================

* NO * NAME * KW * KVAR * LOAD/GENERATION

==============================================================================

4 FILTER 0. -1000. CONSTANT Z LOAD

5 HARM SOURC 0. -400. CONSTANT Z LOAD

5 HARM SOURC 800. 600. CONSTANT I LOAD

*** SOLUTION COMMENTS ***

SOLUTION PARAMETERS

PER UNIT DRIVING VOLTAGE : 1.0000

BRANCH VOLTAGE CRITERIA : 4.00 %

BUS VOLTAGE CRITERIA : 5.00 %

EXACT(ITERATIVE) SOLUTION : YES

TRANSFORMERS MODELED : YES


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BALANCED VOLTAGE DROP AND LOAD

FLOW ANALYSIS (SPECIAL BUS LOAD

REPORT

VOLTAGE EFFECT ON LOADS MODELED TRANSFORMER VOLTAGE DROP MODELED

VOLTAGE DROP CRITERIA: BRANCH = 4.00 % BUS = 5.00

PER UNIT DRIVING VOLTAGE = 1.0000

LOAD BUS: 1 UTILITY DESIGN VOLTAGE:500000 LOAD VOLTAGE:500590 %VD: -.1

------------------------- VOLTAGE ANGLE: .0 DEGREES

LOAD TO: 2 TRX PRI FEEDER AMPS: 2 VOLTAGE DROP: -332. %VD: -.07

PROJECTED POWER FLOW: 814. KW -1209. KVAR 1457. KVA PF: .56 LEADING

LOSSES THRU FEEDER: 1. KW -400. KVAR 400. KVA

LOAD FROM: **** SOURCE FEEDER AMPS: 2 VOLTAGE DROP: 0. %VD: .00

PROJECTED POWER FLOW: 814. KW -1209. KVAR 1457. KVA PF: .56 LEADING

LOSSES THRU FEEDER: 0. KW 0. KVAR 0. KVA

LOAD BUS: 5 HARM SOURC DESIGN VOLTAGE: 13800 LOAD VOLTAGE: 13981 %VD: -1.3------------------------- VOLTAGE ANGLE: -.9 DEGREES

PROJECTED SPECIAL BUS LOAD: 810. KW 197. KVAR

LOAD FROM: 3 TRX SEC FEEDER AMPS: 34 VOLTAGE DROP: 6. %VD: .04

PROJECTED POWER FLOW: 810. KW 197. KVAR 834. KVA PF: .97 LAGGING

LOSSES THRU FEEDER: 0. KW 0. KVAR 0. KVA

5 BUSES

*** T O T A L S Y S T E M L O S S E S ***

3. KW -378. KVAR


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Based on the frequency scan report results, you will be able to

decide if there is cause to execute a distortion calculation.

If there are large resonance points at frequencies where

harmonic sources exist at high magnitudes, then a distortion

calculation should be executed.

Frequency Scan

The frequency scan requires you to define all

harmonic sources, but is unaffected by the source

type or magnitude of harmonics.

The impedance shown in the calculation is the

Thevenin impedance looking into the selected

bus to ground.


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To execute a frequency scan, select F8: Execute Studies

from the Main Menu.

From the Harmonic Investigation Studies window, select F8:

Frequency Scan for Resonance(386).

Enter the file name for the Frequency Scan for Resonance

report as shown below.

After the report name has been entered, press F1: Continue.


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Enter the project title lines for the frequency scan for

resonance study as shown below.

After the project title lines have been entered, press

F1: Continue.


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A window listing of all the buses in the power system will

now appear. This screen allows you to select all of the buses

that will be included in the frequency scan. To select a bus,

position the marker bar over the desired bus using the choice

keys and press F5:

Select Buses for Display. Asterisk brackets will appear

around the bus, indicating that it has been selected.

Pressing F5 again will de-select the bus. For the purposes of

the tutorial, select all of the buses in the power system with

the exception of the utility source bus (Bus 1) as shown

below.

Notice also in this window the double arrow symbol to the

right of bus five; this indicates the presence of a harmonic

source at the indicated bus.


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Press F9: Execute after the buses have been selected, and the

Solution Criteria for HI_WAVE Frequency Scan window

will appear.

This window is similar to the solution criteria window for the

harmonic load flow study; it allows you to specify the

scanning range and the solution criteria for the frequency

scan.


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Enter the data for this screen as shown below.

Notice that in theDefine Scanning Range window the data

are entered manually, while in the Select the Solution Criteria

window the choice keys are used to toggle through a list of

options.


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When finished, press F1: Execute and HI_WAVE will

execute the frequency scan for resonance analysis. When the

analysis is complete, the program returns you to the

HI_WAVE Main Menu.

View the Frequency Scan Report

To view the report results, select F7: Edit/Scan

files from the HI_WAVE Main Menu.

Enter the frequency scan report name as shown

below.


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Press F1: Continue to view the frequency scan for resonance

report below.

Frequency Scan Criteria

Text Output


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C R I T E R I A O F F R E Q U E N C Y

S C A N

FUNDAMENTAL FREQUENCY: 60.HZ

START FREQUENCY: 60.HZ

SCAN STEP SIZE: 20.HZ

SCAN STEPS: 75

EQUIVALENT IMPEDANCE REPORTED IN PER UNIT

WITH ONE PER UNIT CURRENT

INJECTED AT SELECTED BUSES

BASED ON BUS NOMINAL VOLTAGE AND 100MVA POWER BASE

BOTH AERIAL AND GROUND MODES ARE SELECTED

NONLINEAR FREQUENCY DEPENDENT BRANCHES

ARE SELECTED

MOTORS ARE FROM CONTRIBUTION DATA

SPECIAL LOADS ARE INCLUDED IN THE STUDY


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L E G E N D O F T E R M I N O L O G Y

FREQUENCY SCAN: INJECTING 1 PER UNIT CURRENT ATTHE HARMONIC SOURCE LOCATIONS,

REPORTING SYSTEM BUS VOLTAGES

(EQUIVALENT IMPEDANCES)

FOR A RANGE OF FREQUENCIES

SET UP BY USER

BUS EQUIVALENT IMPEDANCE: THE IMPEDANCE SEEN FROM THE

USER SELECTED BUS

DRIVING BUS: ANY BUS WITH A HARMONIC

SOURCE

HARMONIC SOURCE: REPLACED BY CONSTANT ONE

PER UNIT CURRENT SOURCE

R PU: REAL PART OF COMPLEX IMPEDANCE

IN PER UNIT

JX PU: IMAGINARY PART OF COMPLEX IMPEDANCE

IN PER UNIT

Z PU: MAGNITUDE OF IMPEDANCE

IN PER UNIT


BUS VOLTAGE R (OHM) JXL (OHM) -JXC (OHM)==============================================================================

4 FILTER 13800.

POS SEQ. .00 .00 190.44

ZERO SEQ. .00 .00 .00

5 HARM SOURC 13800.

POS SEQ. .00 .00 476.10

ZERO SEQ. .00 .00 .00


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C O N T R I B U T I O N D A T A

CONTRIBUTION VOLTAGE BASE

FROM NAME TO NAME L-L MVA XD"(PU) X/R

==============================================================================

UTILITY 1 UTILITY 500000. 3P-KA: 1.155 30.0

TYPE: UTILITY 1P-KA:

POS SEQUENCE IMPEDANCE (100 MVA BASE) .00333 + J .09994 PER UNIT

MOTOR 5 HARM SOURC 13800. 1.000 .25000 15.0

TYPE: IND. MOTOR KW/HP: 1000. RPM: 1800.

POS SEQUENCE IMPEDANCE (100 MVA BASE) 1.66667 + J 25.00000 PER UNIT

F E E D E R D A T A

FEEDER FROM FEEDER TO QTY VOLTS LENGTH FEEDER DESCRIPTIONNo. NAME No. NAME /PH L-L FEET SIZE TYPE DUCT INSUL

==============================================================================

1 UTILITY 2 TRX PRI 1 500000. 264000.


B/2: .004000 PER UNIT % SERIES COMP: 200.0


3 TRX SEC 4 FILTER 1 13800. 1000. 250 C N XLP

POS seq Z .0891 + J .0396 OHMS/M FEET .04679 + J .02079 PU


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PRIMARY SIDE VOLTS PRI * SECONDARY SIDE VOLTS SEC NOMINALNo. NAME CONN L-L FLA * No. NAME CONN L-L FLA KVA

==============================================================================

2 TRX PRI D 500000. 6. 3 TRX SEC YG 13800. 209. 5000.

POS SEQ Z .7960 + J 7.9603 PERCENT .15921 + J 1.59206 PER UNIT

Equivalent Bus Impedance at Fundamental Frequency

B U S E Q U I V A L E N T

I M P E D A N C E AT 60 HZ AND ABOVE

HI_WAVE reports equivalent bus impedance for

all harmonic frequencies, according to user-

defined steps, up to and including the maximum

selected frequency. For the purposes of this

illustration, the middle frequencies are omitted.


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To exit the viewing mode press F10: and the program will ask

whether or not you want to exit. Press D(on't) and Enter in

response to the prompt, and the program will return to the

Main Menu.

View the Graphical Output of the

Frequency Scan Report

This step of the tutorial is required so that you can decide

whether or not distortion calculations need to be executed on

the project.

To view a drawing of the frequency report, from the

HI_WAVE Main Menu select F4: Graphics Output and the

HI_WAVE Graphing Utility window will appear. From this

window select F1: Frequency Scan Drawings as illustratedbelow.


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When F1: Frequency Scan Drawings is selected, the Select

Drawing Name window will appear. In this window, there

will be a list of frequency scan file names. Select the SCAN

file as shown below, and press Enter.


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When Enter is pressed, the buses that you selected for

inclusion in the frequency scan calculation will appear in a

window on the right side of the screen.

From this window select Bus 2 for graphical output by

positioning the marker bar over the bus name and pressing

F1: Select Data. Arrows will appear to the right of the bus

name to indicate that it has been selected.


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Next, access the Plot Data Choices data choice field and

select H Order V Z (harmonic order versus impedance) from

the list of provided options using the PgUp/PgDn keys.

Press F2: Plot Selected, and HI_WAVE will generate the

requested drawing, as shown below.


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Using the same process outlined above, de-select Bus 2,

select Buses 3, 4, and 5 for simultaneous output. The

drawing of the combined plots is illustrated below.


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To save this drawing to a plot file press F9: Save Plot File.

Pressing F10: Exit will not save the drawing into a plot file, it will

only save the screen data.

After pressing F9, the Save Plot File window will appear.

Enter the output file name and plot description as shown

below.


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Press F1: Continue/Save to save the plot file under

the entered report name, and HI_WAVE will return

to the drawing window.

Press F10: Exit to access the HI_WAVE

Graphing Utility window.

Press F10: Exit to Main Menu.


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1


Analysis

Using PCs to Solve

Harmonic ProblemsSection D4-E1-E2

D4. Execute Voltage and Current Distortion

Calculations........

The distortion calculations determine the system's total

voltage distortion at each selected bus, and the total

current distortion at each selected branch.

To perform the distortion calculations, from the

HI_WAVE Main Menu select F8: Execute Studies, and

the Harmonic Investigation Studies window will appear.

From this window select F7: DistortionCalculations(386).


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HI_WAVE will prompt you to enter a report name for the

distortion calculation. Enter the report name DIST as shown

below. The date and time will be entered automatically by

HI_WAVE.


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Press F1: Continue and the Enter Project

Title Lines window will appear.

Enter title lines for the distortion calculation

report as shown below.


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4

Press F1: Continue, and a window containing a list of all the

buses in the power system will appear. In this window you

specify the buses to be included for graphical output in the

voltage distortion calculation.

To select a bus, position the marker bar over the desired bus

record, and press F5: Select Buses For Display. When a bus

record is selected, asterisk brackets appear around the bus name.

Select all of the bus records except the utility bus (Bus 1) as

shown below.


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5

When all of the buses are selected, press F9: Execute, and the

Select Branch Flow Records screen illustrated below will appear.


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6

In this screen, you select the branches to be included in graphicaloutput of the current distortion calculation.

To select a branch, position the marker bar over the desired branch

and press F5: Toggle Select. When a branch is selected, asterisk

brackets appear around the branch name, and the branch name

appears in the Selected Records window on the right side of the

screen.

For the purposes of the tutorial, select ALL of the branches in the

system for inclusion in the current distortion calculation as shown

below.


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When the branches have been selected, press F9: Execute to

access the Solution Criteria for HI_WAVE Distortion

Calculation screen. In this screen, specify the solution

criteria for the distortion calculation as shown below.

Notice that in the Define the Distortion Calculation Range window,data are entered manually, while in the Select Solution Criteria

window, data options are toggled using the choice keys.


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When the solution criteria have been entered, press F1:

Execute, HI_WAVE executes the distortion calculations.

After the calculations are complete, the program will return

control to the Main Menu. You may now view the distortion

calculation text report.

View the Distortion Calculation Report


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To view the report results, select F7: Edit/Scan Files from

the Main Menu. HI_WAVE will prompt you for the report

name, Enter DIST in response to the prompt, as shownbelow.

Select F1: Continue to continue.

Important Features of the Distortion

Calculation Report


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C R I T E R I A O F D I S T O R T I O N

S T U D Y

FUNDAMENTAL FREQUENCY: 60.HZ

MAXIMUM ORDER OF HARMONICS: 25TH

TOTAL VOLTAGE AND CURRENT DISTORTION IS BASED ON THE LOAD FLOW STUDY

TOTAL VOLTAGE DISTORTION WILL BE REPORTED

HARMONIC RMS VOLTAGE WILL BE REPORTED

TOTAL CURRENT DISTORTION WILL BE REPORTED

HARMONIC RMS CURRENT WILL BE REPORTED

NONLINEAR FREQUENCY DEPENDENT BRANCHES ARE SELECTED

BOTH AERIAL AND GROUND MODES ARE SELECTED

MOTORS ARE FROM CONTRIBUTION DATA

SPECIAL LOADS ARE INCLUDED IN THE STUDY

IT FACTOR WILL BE REPORTEDTRANSFORMER PHASE SHIFT MODELED

L E G E N D O F T E R M I N O L O G Y

LF VOLTS: LOAD FLOW VOLTAGE RESULTS

V_THD: TOTAL HARMONIC VOLTAGE DISTORTION

V_RMS: ROOT-MEAN-SQUARE VOLTAGE MAGNITUDE INCLUDING

FUNDAMENTAL VOLTAGE AND HARMONIC VOLTAGES

V_TIF: VOLTAGE TELEPHONE INFLUENCE FACTOR

I_THD: TOTAL HARMONIC BRANCH CURRENT DISTORTION

I_RMS: ROOT-MEAN-SQUARE CURRENT MAGNITUDE INCLUDING

FUNDAMENTAL CURRENT AND HARMONIC CURRENTS

IT: INDUCTIVE INFLUENCE IN TERMS OF ROOT-MEAN-SQUARE OF

THE PRODUCT OF CURRENTS AND THE INFLUENCE WEIGHTING

FACTORS

K: K-FACTOR, TOTAL TRUE-RMS CURRENT REFERENCE


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H A R M O N I C S O U R C E

BUS: 5 HARM SOURC VOLTAGE: 13800. ID:SKM SIX PULSE KVA: 1000.0

ORDER MAGNITUDE ANGLE ORDER MAGNITUDE ANGLE ORDER MAGNITUDE ANGLE

==============================================================================

1 100.000 -12.6 5 37.660 107.4 7 12.550 -126.9

11 7.110 -93.2 13 3.350 -50.2 17 2.930 15.9

19 1.670 45.0

H A R M O N I C S O U R C E I N D E XT A B L E

HARMONIC SOURCES HAVE BEEN FOUND AND

INJECTED FOR EACH OF

THE FOLLOWING HARMONIC ORDERS

5 7 11 13 17 19


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BUS VOLTAGE R (OHM) JWL (OHM) -JWC (OHM)

==============================================================================

4 FILTER 13800.

POS SEQ. .00 .00 190.44

ZERO SEQ. .00 .00 .00

5 HARM SOURC 13800.

POS SEQ. .00 .00 476.10

ZERO SEQ. .00 .00 .00

C O N T R I B U T I O N D A T A

CONTRIBUTION VOLTAGE BASE

NAME No. NAME L-L MVA XD"(PU) X/R

==============================================================================

UTILITY 1 UTILITY 500000. 3P-KA: 1.155 30.0

TYPE: UTILITY 1P-KA:

POS SEQUENCE IMPEDANCE (100 MVA BASE) .00333 + J .09994 PER UNIT

MOTOR 5 HARM SOURC 13800. 1.000 .25000 15.0

TYPE: IND. MOTOR KW/HP: 1000. RPM: 1800.

POS SEQUENCE IMPEDANCE (100 MVA BASE) 1.66667 + J 25.00000 PER UNIT


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F E E D E R D A T A

FEEDER FROM FEEDER TO QTY VOLTS LENGTH FEEDER DESCRIPTION

No. NAME No. NAME /PH L-L FEET SIZE TYPE DUCT INSUL

==============================================================================

1 UTILITY 2 TRX PRI 1 500000. 264000.


B/2: .004000 PER UNIT % SERIES COMP: 200.0


3 TRX SEC 4 FILTER 1 13800. 1000. 250 C N XLP


3 TRX SEC 5 HARM SOURC 1 13800. 1000. 250 C N XLP



PRIMARY SIDE VOLTS PRI * SECONDARY SIDE VOLTS SEC NOMINAL

No. NAME CONN L-L FLA * No. NAME CONN L-L FLA KVA

==============================================================================

2 TRX PRI D 500000. 6. 3 TRX SEC YG 13800. 209. 5000.

POS SEQ Z .7960 + J 7.9603 PERCENT .15921 + J 1.59206 PER UNIT


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14

T O T A L V O L T A G E D I S T O R T I O NBUS NAME NOMINAL VOLTS V_RMS V_THD(%) V_TIF

==============================================================================

1 UTILITY 500000. 500589.60 .0003 .5003

2 TRX PRI 500000. 501026.60 2.0522 $ 11.6989

3 TRX SEC 13800. 14043.35 9.0340 $ 36.7486

4 FILTER 13800. 14046.98 9.0903 $ 37.2840

5 HARM SOURC 13800. 14038.08 9.0715 $ 36.5682

V O L T A G E D I S T. S U M M A R YTHERE ARE 4 VOLTAGE DISTORTION EXCEEDING IEEE STD 519 STANDARD

==============================================================================

BUS NAME NOMINAL VOLTS V_RMS V_TH(%) V_TIF

==============================================================================

2 TRX PRI 500000. 501026.60 2.0522 $ 11.6989

3 TRX SEC 13800. 14043.35 9.0340 $ 36.7486

4 FILTER 13800. 14046.98 9.0903 $ 37.2840

5 HARM SOURC 13800. 14038.08 9.0715 $ 36.5682


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15

T O T A L C U R R E N T D I S T O R T I O N

FROM/NAME TO/NAME VOLTAGE I_RMS(A) I_THD(%) K IT

==============================================================================

1 UTILITY 2 TRX PRI 500000. 1.68 .01 1.00 1.33

2 TRX PRI 3 TRX SEC 500000. 1.97 111.14 16.19 480.16

3 TRX SEC 4 FILTER 13800. 47.50 50.47 8.17 13356.21

3 TRX SEC 5 HARM SOURC 13800. 39.74 57.54 7.55 8852.18

Only the harmonic voltage spectrum report for Bus 3 is shown. When you view the

distortion report in HI_WAVE, every bus will be reported in the same format.

HARMONIC VOLTAGES FOR BUS 3 TRX SEC VOLTAGE: 13800.0

==============================================================================

HARMONIC HARMONIC PHASE DISTORTION IEEE-519

ORDER VOLT ANGLE PERCENT LIMIT

==============================================================================

1 13986.400 -.91

5 1115.062 -79.19 7.972$ 3.000

7 587.273 -78.49 4.199$ 3.000

11 82.987 175.88 .593 3.000

13 30.174 -40.28 .216 3.000

17 19.608 -131.83 .140 3.000

19 8.273 -3.71 .059 3.000

Harmonic Voltage Spectrum Report


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++SUMMARY+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

VOLTAGE V_RMS V_TIF V_THD(%) IEEE-519 LIMIT

13800.0 14043.3 36.74 9.03$ 5.0

$ INDICATES A VIOLATION OF IEEE STD 519 LIMITS FOR VOLTAGE

Harmonic Current Spectrum Report


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Only the harmonic current spectrum report for Branch 2-3 is shown. When you view

the distortion report in HI_WAVE, every branch will be reported in the same format.

HARMONIC CURRENT FOR BRANCH 2 TRX PRI 3 TRX SEC

IEEE-519 IS NOT APPLICABLE TO THIS BRANCH

==============================================================================

HARMONIC HARMONIC PHASE DISTORTION IEEE-519

ORDER AMPS ANGLE PERCENT LIMIT

==============================================================================

1 1.322

5 1.360 -162.09 102.823

7 .557 -160.11 42.137

11 .026 -110.92 1.986

13 .008 33.41 .622

17 .006 132.92 .426

19 .005 -98.04 .356

++SUMMARY+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

VOLTAGE:500000. I_RMS: 1.97 IT: 480.16 K: 16.19 I_THD(%): 111.14

$ INDICATES A VIOLATION OF IEEE STD 519 LIMITS FOR CURRENT


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18

Capacitor and Filter Spectrum Report

Only the capacitor/filter spectrum report for the

capacitor at Bus 4 is shown. When you view the

distortion report in HI_WAVE, every capacitor

bank and filter will be reported in the same format.

HARMONIC SPECTRUM FOR CAPACITOR BANK ON BUS 4 FILTER

==============================================================================

HARMONIC CURRENT

NUMBER (AMPS) KW KVAR KVA PF

==============================================================================

1 42.41 .0000 -1027.6320 1027.6320 .00

5 16.99 .0000 -32.9866 32.9866 .00

7 12.59 .0000 -12.9393 12.9393 .00

11 2.83 .0000 -.4185 .4185 .00

13 1.23 .0000 -.0667 .0667 .00

17 1.07 .0000 -.0388 .0388 .00

19 .51 .0000 -.0079 .0079 .00


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20

View Graphical Output of the Voltage

Distortion

From the HI_WAVE Main Menu, select F4:

Graphics Output, and the HI_WAVE Graphing

Utility window will appear. From this window,

select F2: Voltage Distortion, as shown below.


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As for the frequency scan, a list of the available distortion

report files will appear in a window on the right side of the

screen. Select the DIST file, as shown below.


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When the file has been selected, press F1: Select and

Return, and a list of the buses that were selected for

graphical output during the voltage distortion calculations

will appear in a window on the right side of the screen.

Select all of the buses for graphical output in the same

manner as for the frequency scan. In the Plot Data Choices

choice field, select Wave form in PU using the choice keys;

press F2: Plot Selected to generate the graph shown below.


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You will notice that there is moderate voltage distortion,

particularly at Buses 3 and 4.

Press F10: Exit/Save to return to the HI_WAVE Graphing

Utility Window.

View Graphical Output of the Current

Distortion

From the Graphing Utility Window, select F3:

Current Distortion as shown below.


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Select the DIST file, as shown below.

A list of all of the branches that were selected for inclusion in

the current distortion calculation will appear in a window on

the right side of the screen. Select Branches 2-3 and 3-4 for

graphical output.


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25

In the Plot Data Choices choice field, select Wave form in

PU using the choice keys; press F2: Plot Selected to generate

the graph shown below.


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26

As the figure above illustrates, there is extreme current

distortion in both branches.

When finished reviewing the current distortion graphical

results, press F10: Exit until the HI_WAVE Main Menu

appears.

E1. Make System Improvements........

The next phase of the tutorial deals with modifying the

power system to compensate for the harmonic distortion

that the reports and graphics indicate.

The capacitors at Buses 4 and 5 will be

tuned into single-tuned filters.


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How To Design a Filter:

1. Select base power frequency : 25, 50 or 60 Hz.

2. Select SF, HP or C

3. Select connection Y, D or YG

4. Select target harmonic number

5. Select capacitor can voltage rating

6. Select rated capacitor size in kVAR's

7. For SF filters specify Q

Q = X/R

X = filter resonant inductance

Q factor graph can be obtained from filter mfg.

Normal range of Q is 50-150

8. For HP filters specify an optimal factor:

M = L / (R*R*C)

9. This provides steady state data, see filter manufacturer for

transient and changing load limits.


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28

Filter Design

1. Target harmonic order can be a decimal value, usually

lower than the harmonic to be attenuated.

2. Select type of filter:

SF = single tuned low pass filter

C in series with

L in series with

R

HP = High pass or multiple order filter

C in series with

L R which are in parallel

C = Capacitor bank only

3. You can model up to five filters on each bus.

4. You can use the interactive filter designer.

5. See SKM page UG 6-17 for more details.


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29

Turn the Capacitor at Bus 4

into a Single-Tuned Filter

Now that the distortion has been calculated and

the system resonance points determined, a filter

can be effectively designed and applied at Bus 4.

Select F3: Bus Records from the HI_WAVE Main Menu;

the HI_WAVE Bus Record editor screen will appear.

Position the marker bar over the Bus 4 record; press F9:

Load/Filter and then Enter to access the Harmonic Filter

Data window shown below and begin filter design.


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30

Notice that the capacitor data has been saved in the bus record

and is available for editing. Access the capacitor record (any

data field associated with the capacitor) and press F6: Filter or

Capacitor.

This accesses the Interactive Filter Designer. The filter designer

screen with the capacitor data will appear.

Tune the capacitor into a single tuned filter by changing the datain this window to match that below.


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31

The capacitor is now tuned into a 3.6th harmonic order

single-tuned filter. Press F6: Calculate Filter or Capacitor

& Return Data, and HI_WAVE will return to the Harmonic

Filter Data window, automatically inserting the calculated

positive sequence filter data into the bus record, as shown

below.


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Press F1: Save to save the filter data and return to the list of

bus records. You are now ready to modify the capacitor at

the harmonic source bus.


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33

Tune the Bus 5 Capacitor Bank into a

Single-tuned Filter

You will now tune the capacitor at Bus 5 into a 5th order,

single-tuned filter.

The procedure is identical to that used for Bus 4. When you

return to the list of bus records, the load/filter data should still

be visible.

Position the marker bar over the Bus 5 record; press Enter to

access the Harmonic Filter Data window shown below.


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Press F6: Filter or Capacitor to access the interactive filter

design screen, and edit the capacitor data to match the single-

tuned filter data shown below.


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35

The capacitor is now tuned into a 5th harmonic order single-

tuned filter.

Press F6: Calculate Filter or Capacitor & Return Data,

and HI_WAVE will return to the Harmonic Filter Data

window, automatically inserting the calculated positive and

zero sequence filter data into the bus record, as shown below.


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Press F1: Save to save the data and return to the list of bus

records. The filters are now completed, and the harmonic

studies may be re-executed and the results compared to the

previous studies.

Press F10: Exit to return to the HI_WAVE main menu.


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E2. Comparing Results........

Re-execute HI_WAVE Studies

Now that the filters have been designed and applied

to the system, the harmonic studies must be re-

executed to determine how the changes have affected

the system resonance and distortion. Refer to

Sections D1 through D4 to execute the harmonic

studies and review the study results.

Since the aim is to compare the new study results with the old

ones, make certain that different report names are used for the

new studies so that the original reports are not overwritten.

In this project provided, the suffix _FLT has been

added to the report names, indicating that FiLTers

have been applied. Thus the original frequencyscan report name SCAN becomes SCAN_FLT in

the new case, and so on for the other studies.


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38

Compare Old and New Graphical OutputResults

When the HI_WAVE studies have been re-executed on

the new case and the report results reviewed, graphical

results may be compared by combining output from

both cases on a single graph.

From the HI_WAVE Main Menu, select F4:

Graphics Output, and the Graphing Utility

Window shown below will appear.


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39

Compare the Frequency Scan Plots at Bus 4

From the Graphing Utility window, select F1: Frequency

Scan Drawings. A list of scan files will appear on the right

of the screen. Position the marker bar over the SCAN_FLT

file, and press Enter.


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From the list of buses that appears in the right-hand window,

select Bus 4 by positioning the marker bar over the bus name

and pressing F1: Select Data.

Ensure that H Order V Z appears in the Plot Data Choices

data field, and press F2: Plot Selected. The drawing

illustrated below will appear.


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41

To compare these new results with the previous results,

combine the old and new frequency scan drawings on a single

graph by first pressing F5: Add New File.

HI_WAVE recalls the list of available frequency scan files.

Position the marker bar over the SCAN file and press Enter.

Ensuring that the Plot Data Choices field reads H Order V Z,

position the marker bar over Bus 4. Press F1: Select Data to

select the bus, and F2: Plot Selected to create the drawing.

HI_WAVE automatically combines the drawings, as shown

below. Notice that the Plot Legend shown on the graph is

also updated to include both buses and both file names.


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42

Notice that the large resonance peak at the sixth harmonic

order has been reduced from 69.29 ohms in the SCAN

report to less than 10 ohms in the SCAN_FLT report.

The 70 ohm peak in the SCAN_FLT curve at the 20th

harmonic order is not significant because the 20th harmonic

order is too high to cause serious distortion, and because the

SKM Six Pulse does not generate 20th order harmonics.


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43

Press F10: Exit/Save to return to the HI_WAVE Graphing

Utility Window.

Compare the Current Distortion Plots at

Branches 2-3 and 3-4

Select F3: Current Distortion from the Graphing Utility

Window. From the list of distortion report files, select

the DIST_FLT file and, using the same method

outlined above, produce a drawing of the current

distortion in Branches 2-3 and 3-4 as shown below.


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44

Ensure that the Plot Data Choices choice field

reads Wave form in PU.

For clarity in comparison, and since nearly all distortion

in Branch 2-3 has been eliminated, only Branch 3-4

results will be compared to the original.


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45

De-select Branch 2-3 by positioning the marker bar over the

branch name and pressing F1: Select Plot; the arrow

indicators will disappear indicating that Branch 2-3 has been

de-selected. Press F2: Plot Selected, and the graph will be

updated to exclude that branch.

Using the same procedure outlined above, create a

current distortion graph for Branch 3-4 from the original

distortion calculation report (DIST), and combine the two

drawings. The results are illustrated below.

Using the same procedure outlined above, create a current

distortion graph for Branch 3-4 from the original distortion

calculation report (DIST), and combine the two drawings.

The results are illustrated below.


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46

The current distortion has been reduced from 50.47% to

3.26%. After reviewing the results, press F10: Exit/Save to

return to the Graphing Utility window.


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47

Compare the Voltage Distortion Plots

at Bus 3

From the Graphing Utility window select F2:

Voltage Distortion. From the list of distortion

files, select DIST_FLT. Using the method

outlined above, create a voltage distortion graph

for Bus 3, as shown below.


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Ensure that the Plot Data choice field reads Wave form

in PU. Combine the voltage distortion graph for Bus 3

from the original distortion calculation report (DIST),

and the new distortion calculation report (DIST_FLT).

The results are illustrated below.


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As indicated above, the voltage distortion has been

reduced from 9.03% in the DIST report to 2.01% in

the DIST_FLT report.


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50

You have now completed this HI_WAVE project. Over the

course of executing the tutorial, you have seen the effects of

capacitor bank implementation on the level of harmonic

distortion in the power system.

Using the filter design and implementation techniques

outlined, you have significantly mitigated the harmful effects

of sinusoidal distortion. If so desired, you may continue to

use the completed project as a sample case on which to test

different scenarios or apply different harmonic sources and

filters.


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Have a nice day!

power qualkity analysis

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