advanced power quality analysis - stray voltage, phasor … · · 2011-04-16advanced power...

1

Advanced Power QualityAnalysis

Using PC’s to Solve

Harmonic Problems

Our Circuit

Transmission Line

Source

21

5

4

3

2

OurTransmissionLine....

(-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 toreduce voltage and current distortion.

Later we will do this by converting thepower factor correction capacitors into tunedfilters.

3

Define Feeder Library........

4

Define the Harmonic Source Library

Define Transmission Lines

5

Create Transformer Records

text

Create the Feeders........

6

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

text

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

7

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

Specify the Capacitor Bank

8

Execute Studies........

For most cases, four studies will be executed using the powersystem configuration defined by you, typically in thissequence:

1. Harmonic Load Flow.

2. Frequency Scan for Resonance.

3. Distortion Calculations (current and voltage).

Harmonic Load Flow

9

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

The impedance shown in the calculation is theThevenin impedance looking into the selected busto ground.

10

View the Graphical Output of theFrequency Scan Report

11

Execute Voltage and Current DistortionCalculations........

The distortion calculations determine the system's totalvoltage distortion at each selected bus, and the total

current distortion at each selected branch.

12

View Graphical Output of the VoltageDistortion

13

View Graphical Output of the CurrentDistortion

14

Make System Improvements........

The next phase of the tutorial deals with modifying thepower system to compensate for the harmonic distortion

that the reports and graphics indicate.

The capacitors at Buses 4 and 5 will be tuned intosingle-tuned filters.

Tune the Capacitor at Bus 4 into a Single-Tuned Filter

15

Tune the Bus 5 Capacitor Bank into aSingle-tuned Filter

16

Comparing Results........

Now that the filters have been designed and appliedto the system, the harmonic studies must be re-

executed to determine how the changes have affectedthe system resonance and distortion.

17

Compare the Frequency Scan Plots at Bus 4

18

Compare the Current Distortion Plots atBranches 2-3 and 3-4

19

Compare the Voltage Distortion Plotsat Bus 3

20

Have a nice day!

1



Harmonic ProblemsSection X&A

Basic Tools and Methods ofHarmonic Analysis

We will……

Analyze the current and voltagewave forms using the FourierSIN or COS method

2

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 usesthe Eigen Value

Method.

3

Basics of a Computer Analysis

X. Prepare a One-Line DiagramX1. 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 LibraryA1. 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.

5


D. Execute StudiesD1. Execute demand load analysis (if req’d).

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 SystemE1. Make system improvements.

E2. Comparing results.

6

X1. Our Transmission Line

Transmission Line

Source

21

5

4

3

X1. OurTransmissionLine....

(-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

7

Cable or Transmission Line Modeling

In a low voltage system non-linear modeling isusually not required.

Cables and lines can be modeled by Cascaded PImodeling or Distributed Equivalent PI modeling.

The Distributed Equivalent PI method is used inHI_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 cable1000 circuit feetin 3.5 inch non-metallic conduit

21

5

4

3

Feeder

Feeder

8

X3. Our Capacitor Banks andHarmonic Source....

21

5

4

3HarmonicSource

Capacitor Bank #5

Capacitor Bank #4

X3. OurCapacitorBanksandHarmonicSource....

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 andTransformers....

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 toreduce voltage and current distortion.

Later we will do this by converting thepower factor correction capacitors into tunedfilters.

Let's go to the computer lab.

10

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 theavailable 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

14

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 betweenmagnetic induction and magnetic force

Relative Permittivity is related to the dielectricconstant

15

Select F10:Continue and make sure the Menu datamatches 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_WaveLibraries menu select

F5:Harmonic Sources

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Press Enter then press F5: Enter/Edit Detailed Model

Load Types

Constant Impedance = incandescent lightsor resistance heaters - loads that vary with

the square of the voltage applied.

Constant kVA = motors, constant wattageballast's - loads that attempt to remain atthe same kW input regardless of voltage

applied.

Constant Current = load whose current isaffected 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 orderharmonics.

Six pulse (Rice FFT method)Pros: Samples the direct current wave formconsidering 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 unitswith 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 tomove to screen two.

When all the data has been checked, press F1: Return with Dataand then F1: Save to exit the screen and save the source in thelibrary.

The source name will appear onthe left-hand side of the screenat the bottom of the source listas 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_WAVELibraries Menu, select F8:Transmission Lines andthe Transmission LineLibrary shown will appear.

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Press Enter This library allows you to enter detailedfrequency 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

1



Harmonic ProblemsSection B&C

B1. Create the Transmission Line.....…

Return to the Main menu. Press F10: Exit

2

Press F1: Branch Records to obtain the menu SIMILAR to themenu below. Hit F9 to turn scan on.

text

On the left side of the menu, highlight the record line that saysFrom Bus 1 (Utility) to Bus 2 (TRX Pri). Then press Return to getthe Menu as shown below:

3

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 inthe transmission line library, as illustrated below.

Position the marker bar over the Transmission Line ID name, andpress Enter. This will automatically enter the model into the

branch record.

4

The name of the selected model Transmission will appear in theFrequency Dep. Model data field as shown in the figure below.This is important!

The transmission line branch record is now complete and may besaved 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 thescreen, verifying that the branch record has been created and

saved.

5

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

Transformer Modeling

Program considers non-linearity caused by overexcitation or overloading.

Transformer connections and phase shifting are modeled.

Phase shifting is important when more than one sourceof harmonics exists.

Program considers impedance versus frequency using aLaplace transformation. This modeling is automatic.

Consider using EXISTING vs. DESIGN when modelingtransformers.

6

The transformer branch record is now complete. Press F1: Saveto 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 theMenu as shown below.

7

Press F1: Save to save the record and F10: Exit to return to theleft-hand window of the Branch Record Editor.

On the left side of the menu, highlight the record line that saysFrom Bus 3 (TRX Sec) to Bus 5 (Harm Source). Then pressReturn to get the Menu as shown below.

text

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Press F1: Save to save the record and F10: Exit to returnto 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 thatsays From C UTILITY to 1 UTILITY. Then pressReturn to get the Menu as shown below.

Note that the fault duty contribution record is displayed on aline different than the specified branch, and is identifiedwith a "C" to the left of contribution type, as shown below.

For the purposes of this tutorial, a utility fault duty will bedefined 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 thatsays From C MOTOR to 5 HARM SOURC. Then pressReturn to get the Menu as shown below.

Note that the fault duty contribution record is displayed on aline 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 samemanner as the utility fault duty, specifying the contribution dataas 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 thespecial co-generator model.

Generators operating in parallel with the Utility may bedefined as special bus generation load in the bus records.

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C1. Specify the Source Bus ........

All of the branches have now been defined; the next taskwill be to enter data for the bus records. To exit the

Branch Record Editor, press F10: Exit, and the programwill return to the HI_WAVE Main Menu.

From the HI_WAVE Main Menu select F3: Bus Recordsas illustrated above, and the HI_WAVE Bus Records

screen below will appear.

Note that the bus names and numbers already exist in the bus recordeditor. These buses were defined automatically when the connectingbranches were created. Your task in the bus record editor is to defineend use loads, special bus loads, harmonic source data and/or filterdata for the buses.

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To specify a source bus, press F7: Source Bus from the figureabove, and the Define Source Bus Records window will appear asshown below.

Specify Bus 1 as the source bus, as shownabove. When the source bus has been

specified, press F10: Exit to return to thelist 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 Datascreen shown below will appear. Press Enter to access the screen.

When the screen is accessed, a harmonic source may be selected bypressing F5: Harmonic Source Library; the list of sources in theharmonic source library will appear as shown below

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Position the marker bar on the Tutorial Source and press Enter toselect it. HI_WAVE returns to the Harmonic Source/Filter Datascreen, automatically inserting the source into the bus record. Toverify 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 illustratedbelow.

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 theInteractive Designer for Filters and Capacitor Bankswindow shown below.

15

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

16

Press F1: Save to save the capacitor data withBus 5 and return to the list of bus records on theleft where the capacitor data for Bus 4 will now

be specified.

Position the marker bar over Bus 4 and press Enter to access theHarmonic Source/Filter Data entry window shown below. Makesure that Bus 4 has been selected by checking the bus recordnumber in the upper left-hand portion of this window.

17

Press F6: Filter or Capacitor to access the Filter/Capacitor designwindow. Enter the capacitor data shown below.

When this data has been entered, press F6: Calculate Filter orCapacitor & Return Data. HI_WAVE will calculate thecapacitor data, insert the data into the bus record, and return controlto the Harmonic Filter Data window, as shown below.

18

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 thenetwork topology for the entire tutorial project, and can begin toexecute HI_WAVE studies to scan the system for resonance and

harmonic distortion.

1



Harmonic ProblemsSection D1-D2-D3

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

You have now configured the networktopology for the entire tutorial project, and canbegin to execute HI_WAVE studies to scan thesystem for resonance and harmonic distortion.

2

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

1. Demand Load Analysis.

2. Harmonic Load Flow.

3. Frequency Scan for Resonance.

4. Distortion Calculations (current and voltage).

3

In the case of the Tutorial, executing a Demand Load Analysis isnot necessary. The reasons for executing the studies in thissequence will be explained during the course of the analysissections.

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

Normally, you would have specified end use load and/orspecial bus loads in a project in which case a Demand LoadAnalysis would be executed.

Since the only loads in this project are harmonic sources, aDemand Load Analysis is not necessary; the Harmonic LoadFlow Program models all harmonic source load data. Had youspecified end use loads or special bus loads, the Demand LoadAnalysis would have been the first study executed.

4

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 safety factors.

Demand load analysis does not allow loops, only radialfeeders.

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.

5

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

From the main menu select F8: Execute Studies, and theHarmonic Investigation Studies screen will appear.

Select F2: Harmonic Load Flow from this screen, and thereport 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 elementsincluding filters.

Harmonic load flow can have looped system.

Press F1: Continue, and enter title lines for the study asshown 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, thesystem modeling requirements and the solution criteria.

These criterion categories should be reviewed to discover theavailable options.

For the purposes of the tutorial, enter the criteria optionsshown below.

Press F1: Continue, and HI_WAVE will execute theharmonic load flow study.

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Review the Harmonic Load Flow Report

After executing the harmonic load flow study, theprogram will return to the HI_WAVE Main Menu.

To review the harmonic load flow report, selectF7: Edit Scan Files. Enter the harmonic loadreport file name in response to the HI_WAVEprompt, as shown below or select F3: to view allavailable files.

Press F1: Continue, and the report shown below will bedisplayed.

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 AFEEDER 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 dataunder the Branch Load Data heading. Since there is no suchdata 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

<<PERCENT VOLTAGE DROPS ARE BASED ON NOMINAL DESIGN VOLTAGES>>

12

BALANCED VOLTAGE DROP AND LOADFLOW ANALYSIS (SPECIAL BUS LOADREPORTVOLTAGE 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

13

To exit the viewing mode and return to the Main Menu, pressF10 and the program will ask whether or not you want to exit.Press D(on't), then Enter, and the program will return to theMain Menu.

D3. Execute the Frequency Scan ForResonance Study........

The next study to be performed is the frequency scan forresonance which does not rely on the data generated in thetwo previous studies.

This study does not take harmonic sources intoconsideration, rather it injects a 1 per unit current into thesystem in order to reveal the system's characteristicresonance points.

14

Based on the frequency scan report results, you will be able todecide if there is cause to execute a distortion calculation.

If there are large resonance points at frequencies whereharmonic sources exist at high magnitudes, then a distortioncalculation should be executed.

Frequency Scan

The frequency scan requires you to define allharmonic sources, but is unaffected by the sourcetype or magnitude of harmonics.

The impedance shown in the calculation is theThevenin impedance looking into the selectedbus to ground.

15

To execute a frequency scan, select F8: Execute Studiesfrom 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 Resonancereport as shown below.

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

16

Enter the project title lines for the frequency scan forresonance study as shown below.

After the project title lines have been entered, pressF1: Continue.

17

A window listing of all the buses in the power system willnow appear. This screen allows you to select all of the busesthat will be included in the frequency scan. To select a bus,

position the marker bar over the desired bus using the choicekeys and press F5:

Select Buses for Display. Asterisk brackets will appeararound the bus, indicating that it has been selected.

Pressing F5 again will de-select the bus. For the purposes ofthe tutorial, select all of the buses in the power system withthe exception of the utility source bus (Bus 1) as shownbelow.

Notice also in this window the double arrow symbol to theright of bus five; this indicates the presence of a harmonicsource at the indicated bus.

18

Press F9: Execute after the buses have been selected, and theSolution Criteria for HI_WAVE Frequency Scan windowwill appear.

This window is similar to the solution criteria window for theharmonic load flow study; it allows you to specify thescanning range and the solution criteria for the frequencyscan.

19

Enter the data for this screen as shown below.

Notice that in the Define Scanning Range window the dataare entered manually, while in the Select the Solution Criteriawindow the choice keys are used to toggle through a list ofoptions.

20

When finished, press F1: Execute and HI_WAVE willexecute the frequency scan for resonance analysis. When theanalysis is complete, the program returns you to theHI_WAVE Main Menu.

View the Frequency Scan Report

To view the report results, select F7: Edit/Scanfiles from the HI_WAVE Main Menu.

Enter the frequency scan report name as shownbelow.

21

Press F1: Continue to view the frequency scan for resonancereport 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 YS 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 BRANCHESARE 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 AT THE 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 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

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

25


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

Equivalent Bus Impedance at Fundamental Frequency

B U S E Q U I V A L E N TI M P E D A N C E AT 60 HZ AND ABOVE

HI_WAVE reports equivalent bus impedance forall harmonic frequencies, according to user-defined steps, up to and including the maximumselected frequency. For the purposes of thisillustration, the middle frequencies are omitted.

26

To exit the viewing mode press F10: and the program will askwhether or not you want to exit. Press D(on't) and Enter inresponse to the prompt, and the program will return to theMain Menu.

View the Graphical Output of theFrequency Scan Report

This step of the tutorial is required so that you can decidewhether or not distortion calculations need to be executed onthe project.

To view a drawing of the frequency report, from theHI_WAVE Main Menu select F4: Graphics Output and theHI_WAVE Graphing Utility window will appear. From thiswindow select F1: Frequency Scan Drawings as illustratedbelow.

27

When F1: Frequency Scan Drawings is selected, the SelectDrawing Name window will appear. In this window, therewill be a list of frequency scan file names. Select the SCANfile as shown below, and press Enter.

28

When Enter is pressed, the buses that you selected forinclusion in the frequency scan calculation will appear in awindow on the right side of the screen.

From this window select Bus 2 for graphical output bypositioning the marker bar over the bus name and pressingF1: Select Data. Arrows will appear to the right of the busname to indicate that it has been selected.

29

Next, access the Plot Data Choices data choice field andselect H Order V Z (harmonic order versus impedance) fromthe list of provided options using the PgUp/PgDn keys.

Press F2: Plot Selected, and HI_WAVE will generate therequested drawing, as shown below.

30

Using the same process outlined above, de-select Bus 2,select Buses 3, 4, and 5 for simultaneous output. Thedrawing of the combined plots is illustrated below.

31

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 shownbelow.

32

Press F1: Continue/Save to save the plot file underthe entered report name, and HI_WAVE will returnto the drawing window.

Press F10: Exit to access the HI_WAVEGraphing Utility window.

Press F10: Exit to Main Menu.

1



Harmonic ProblemsSection D4-E1-E2

D4. Execute Voltage and Current DistortionCalculations........

The distortion calculations determine the system's totalvoltage distortion at each selected bus, and the total

current distortion at each selected branch.

To perform the distortion calculations, from theHI_WAVE Main Menu select F8: Execute Studies, andthe Harmonic Investigation Studies window will appear.

From this window select F7: DistortionCalculations(386).

2

HI_WAVE will prompt you to enter a report name for thedistortion calculation. Enter the report name DIST as shownbelow. The date and time will be entered automatically by

HI_WAVE.

3

Press F1: Continue and the Enter ProjectTitle Lines window will appear.

Enter title lines for the distortion calculationreport as shown below.

4

Press F1: Continue, and a window containing a list of all thebuses in the power system will appear. In this window youspecify the buses to be included for graphical output in the

voltage distortion calculation.

To select a bus, position the marker bar over the desired busrecord, 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) asshown below.

5

When all of the buses are selected, press F9: Execute, and theSelect Branch Flow Records screen illustrated below will appear.

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 branchand press F5: Toggle Select. When a branch is selected, asteriskbrackets appear around the branch name, and the branch nameappears in the Selected Records window on the right side of thescreen.

For the purposes of the tutorial, select ALL of the branches in thesystem for inclusion in the current distortion calculation as shownbelow.

7

When the branches have been selected, press F9: Execute toaccess the Solution Criteria for HI_WAVE Distortion

Calculation screen. In this screen, specify the solutioncriteria 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.

8

When the solution criteria have been entered, press F1:Execute, HI_WAVE executes the distortion calculations.

After the calculations are complete, the program will returncontrol to the Main Menu. You may now view the distortion

calculation text report.

View the Distortion Calculation Report

9

To view the report results, select F7: Edit/Scan Files fromthe 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 DistortionCalculation Report

10

C R I T E R I A O F D I S T O R T I O NS 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 REPORTED

TRANSFORMER 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

11

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 ANDINJECTED FOR EACH OF

THE FOLLOWING HARMONIC ORDERS

5 7 11 13 17 19

12


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

13

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

14

T O T A L V O L T A G E D I S T O R T I O N

BUS 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 Y

THERE 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

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 thedistortion 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

16

++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

17

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

18

Capacitor and Filter Spectrum Report

Only the capacitor/filter spectrum report for thecapacitor at Bus 4 is shown. When you view thedistortion 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

20

View Graphical Output of the VoltageDistortion

From the HI_WAVE Main Menu, select F4:Graphics Output, and the HI_WAVE GraphingUtility window will appear. From this window,select F2: Voltage Distortion, as shown below.

21

As for the frequency scan, a list of the available distortionreport files will appear in a window on the right side of the

screen. Select the DIST file, as shown below.

22

When the file has been selected, press F1: Select andReturn, and a list of the buses that were selected for

graphical output during the voltage distortion calculationswill appear in a window on the right side of the screen.

Select all of the buses for graphical output in the samemanner 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.

23

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 GraphingUtility Window.

View Graphical Output of the CurrentDistortion

From the Graphing Utility Window, select F3:Current Distortion as shown below.

24

Select the DIST file, as shown below.

A list of all of the branches that were selected for inclusion inthe current distortion calculation will appear in a window onthe right side of the screen. Select Branches 2-3 and 3-4 forgraphical output.

25

In the Plot Data Choices choice field, select Wave form inPU using the choice keys; press F2: Plot Selected to generate

the graph shown below.

26

As the figure above illustrates, there is extreme currentdistortion in both branches.

When finished reviewing the current distortion graphicalresults, press F10: Exit until the HI_WAVE Main Menu

appears.

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

The next phase of the tutorial deals with modifying thepower system to compensate for the harmonic distortion

that the reports and graphics indicate.

The capacitors at Buses 4 and 5 will betuned into single-tuned filters.

27

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 QQ = X/RX = 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 fortransient and changing load limits.

28

Filter Design

1. Target harmonic order can be a decimal value, usuallylower 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 withL 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.

29

Turn the Capacitor at Bus 4into a Single-Tuned Filter

Now that the distortion has been calculated andthe system resonance points determined, a filtercan 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.

30

Notice that the capacitor data has been saved in the bus recordand is available for editing. Access the capacitor record (any

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

This accesses the Interactive Filter Designer. The filter designerscreen with the capacitor data will appear.

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

31

The capacitor is now tuned into a 3.6th harmonic ordersingle-tuned filter. Press F6: Calculate Filter or Capacitor& Return Data, and HI_WAVE will return to the Harmonic

Filter Data window, automatically inserting the calculatedpositive sequence filter data into the bus record, as shown

below.

32

Press F1: Save to save the filter data and return to the list ofbus records. You are now ready to modify the capacitor at

the harmonic source bus.

33

Tune the Bus 5 Capacitor Bank into aSingle-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 youreturn 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 toaccess the Harmonic Filter Data window shown below.

34

Press F6: Filter or Capacitor to access the interactive filterdesign screen, and edit the capacitor data to match the single-

tuned filter data shown below.

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

36

Press F1: Save to save the data and return to the list of busrecords. The filters are now completed, and the harmonicstudies may be re-executed and the results compared to the

previous studies.

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

37

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

Re-execute HI_WAVE Studies

Now that the filters have been designed and appliedto the system, the harmonic studies must be re-

executed to determine how the changes have affectedthe system resonance and distortion. Refer to

Sections D1 through D4 to execute the harmonicstudies and review the study results.

Since the aim is to compare the new study results with the oldones, 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 beenadded to the report names, indicating that FiLTershave been applied. Thus the original frequency

scan report name SCAN becomes SCAN_FLT inthe new case, and so on for the other studies.

38

Compare Old and New Graphical OutputResults

When the HI_WAVE studies have been re-executed onthe new case and the report results reviewed, graphical

results may be compared by combining output fromboth cases on a single graph.

From the HI_WAVE Main Menu, select F4:Graphics Output, and the Graphing Utility

Window shown below will appear.

39

Compare the Frequency Scan Plots at Bus 4

From the Graphing Utility window, select F1: FrequencyScan Drawings. A list of scan files will appear on the rightof the screen. Position the marker bar over the SCAN_FLT

file, and press Enter.

40

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

illustrated below will appear.

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

HI_WAVE automatically combines the drawings, as shownbelow. Notice that the Plot Legend shown on the graph is

also updated to include both buses and both file names.

42

Notice that the large resonance peak at the sixth harmonicorder has been reduced from 69.29 ohms in the SCANreport to less than 10 ohms in the SCAN_FLT report.

The 70 ohm peak in the SCAN_FLT curve at the 20thharmonic order is not significant because the 20th harmonicorder is too high to cause serious distortion, and because the

SKM Six Pulse does not generate 20th order harmonics.

43

Press F10: Exit/Save to return to the HI_WAVE GraphingUtility Window.

Compare the Current Distortion Plots atBranches 2-3 and 3-4

Select F3: Current Distortion from the Graphing UtilityWindow. From the list of distortion report files, select

the DIST_FLT file and, using the same methodoutlined above, produce a drawing of the current

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

44

Ensure that the Plot Data Choices choice fieldreads Wave form in PU.

For clarity in comparison, and since nearly all distortionin Branch 2-3 has been eliminated, only Branch 3-4

results will be compared to the original.

45

De-select Branch 2-3 by positioning the marker bar over thebranch name and pressing F1: Select Plot; the arrow

indicators will disappear indicating that Branch 2-3 has beende-selected. Press F2: Plot Selected, and the graph will be

updated to exclude that branch.

Using the same procedure outlined above, create acurrent distortion graph for Branch 3-4 from the originaldistortion calculation report (DIST), and combine the two

drawings. The results are illustrated below.

Using the same procedure outlined above, create a currentdistortion graph for Branch 3-4 from the original distortioncalculation report (DIST), and combine the two drawings.

The results are illustrated below.

46

The current distortion has been reduced from 50.47% to3.26%. After reviewing the results, press F10: Exit/Save to

return to the Graphing Utility window.

47

Compare the Voltage Distortion Plotsat Bus 3

From the Graphing Utility window select F2:Voltage Distortion. From the list of distortion

files, select DIST_FLT. Using the methodoutlined above, create a voltage distortion graph

for Bus 3, as shown below.

48

Ensure that the Plot Data choice field reads Wave formin PU. Combine the voltage distortion graph for Bus 3from the original distortion calculation report (DIST),and the new distortion calculation report (DIST_FLT).

The results are illustrated below.

49

As indicated above, the voltage distortion has beenreduced from 9.03% in the DIST report to 2.01% in

the DIST_FLT report.

50

You have now completed this HI_WAVE project. Over thecourse of executing the tutorial, you have seen the effects of

capacitor bank implementation on the level of harmonicdistortion in the power system.

Using the filter design and implementation techniquesoutlined, you have significantly mitigated the harmful effectsof sinusoidal distortion. If so desired, you may continue touse the completed project as a sample case on which to testdifferent scenarios or apply different harmonic sources and

filters.

51

Have a nice day!

advanced power quality analysis - stray voltage, phasor … · · 2011-04-16advanced power...

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