Advanced Power Quality Analysis

Transcription

1 Advanced Power Quality Analysis Using PC s to Solve Harmonic Problems Our Circuit Source Transmission Line 4 1

2 Our Transmission Line... TRANSMISSION LINE: 500 kv 50 miles (2) - "CHUKAR" - 1,780 MCM 84/19 ACSR per phase 98.5' S 19.6' (+Y) 12.9' 12.9' B 1.5' 19.6' S 77.5' 50.0' A C (-X) LINE PHYSICAL CONFIGURATION (+X) 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. 2

3 Define Feeder Library... 3

4 Define the Harmonic Source Library Define Transmission Lines 4

5 Create Transformer Records text Create the Feeders... 5

6 Create the Utility Source... text Create the Motor Contribution Source... 6

7 Specify the Harmonic Sources... Specify the Capacitor Bank 7

8 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 8

9 Execute the Frequency Scan For Resonance Study... The impedance shown in the calculation is the Thevenin impedance looking into the selected bus to ground. 9

10 View the Graphical Output of the Frequency Scan Report 10

11 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. 11

12 View Graphical Output of the Voltage Distortion 12

13 View Graphical Output of the Current Distortion 13

14 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 14

15 Tune the Bus 5 Capacitor Bank into a Single-tuned Filter 15

16 Comparing Results... Now that the filters have been designed and applied to the system, the harmonic studies must be reexecuted to determine how the changes have affected the system resonance and distortion. 16

17 Compare the Frequency Scan Plots at Bus 4 17

18 Compare the Current Distortion Plots at Branches 2-3 and

19 Compare the Voltage Distortion Plots at Bus 3 19

20 Have a nice day! 20

21 Advanced Power Quality Analysis Using PC s to Solve Harmonic Problems Section X&A Basic Tools and Methods of Harmonic Analysis We will Analyze the current and voltage wave forms using the Fourier SIN or COS method 1

22 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. 2

23 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. 3

24 Basics of a Computer Analysis. 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. Basics of a Computer Analysis. 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. 4

25 Basics of a Computer Analysis. D. Execute Studies D1. 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. Basics of a Computer Analysis. E. Evaluate and Modify System E1. Make system improvements. E2. Comparing results. 5

26 X1. Our Transmission Line Source Transmission Line 4 X1. Our Transmission Line... TRANSMISSION LINE: 500 kv 50 miles (2) - "CHUKAR" - 1,780 MCM 84/19 ACSR per phase 98.5' S 19.6' (+Y) 12.9' 12.9' B 1.5' 19.6' S 77.5' 50.0' A C (-X) LINE PHYSICAL CONFIGURATION (+X) 6

27 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 cable 1000 circuit feet in 3.5 inch non-metallic conduit Feeder Feeder 4 7

28 X3. Our Capacitor Banks and Harmonic Source Harmonic Source 1 2 Capacitor Bank #5 4 Capacitor Bank #4 X3. Our Capacitor Banks and Harmonic Source... Capacitor Bank - BUS 5: 400 kvar 13.8 kv rated WYE Connected Capacitor Bank - BUS 4: 1000 kvar 13.8 kv rated WYE connected Harmonic Source: 1000 HP (kva) VFD drive Measured CURRENT DISTORTION per SKM "TUTORIAL" 5th = 37.6% 7th = 12.55% 11th = 7.11% 13th = 3.35% 17th = 2.93% 19th = 1.67% 8

29 X4. Our Utility Source and Transformers... Source: 500 kv 1000 mva (Avail. short ckt.) X/R = 30 Transformer: 500 kv Delta primary 13.8 kv WYE (grounded) secondary 5000/5500 kva 0A/FA Z = 8% X/R = Z = 8% Fault Duty 1000 MVA X/R = 10 4 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. 9

30 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 10

31 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 11

32 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. 12

33 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 13

34 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 14

35 Select F10:Continue and make sure the Menu data matches the data below Press Esc-Abort to return to the menu below 15

36 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 16

37 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. 17

38 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. Modeling The Harmonic Source 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 entire curve in time domain. 18

39 Modeling The Harmonic Source 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. Modeling The Harmonic Source 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. 19

40 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. 20

41 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. 21

42 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 to the HI Wave library menu. 22

43 Goto Section B 23

44 Advanced Power Quality Analysis Using PC s to Solve Harmonic Problems Section B&C B1. Create the Transmission Line... Return to the Main menu. Press F10: Exit 1

45 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: 2

46 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. 3

47 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. 4

48 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. 5

49 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 From Bus 3 (TRX Sec) to Bus 4 (Filter). Then press Return to get the Menu as shown below. 6

50 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 7

51 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 Return to get the Menu as shown below. 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 be specified as an induction motor contribution. 8

52 text Press F10: Exit to return to the Branch Record Editor. 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 Return to get the Menu as shown below. 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. 9

53 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 Record Editor 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. 10

54 C1. Specify the Source Bus... All of the branches have now been defined; the next task will be to enter data for the bus records. To exit the Branch Record Editor, press F10: Exit, and the program will return to the HI_WAVE Main Menu. From the HI_WAVE Main Menu select F3: Bus Records as illustrated above, and the HI_WAVE Bus Records screen below will appear. Note that the bus names and numbers already exist in the bus record editor. These buses were defined automatically when the connecting branches were created. Your task in the bus record editor is to define end use loads, special bus loads, harmonic source data and/or filter data for the buses. 11

55 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. 12

56 C2. Specify the Harmonic Sources... To specify the harmonic source at Bus 5, position the marker bar over 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 13

57 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 sure that 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 may be defined. Press F6: Filter or Capacitor to access the Interactive Designer for Filters and Capacitor Banks window shown below. 14

58 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 Data window, as shown below. 15

59 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. 16

60 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 control to the Harmonic Filter Data window, as shown below. 17

61 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. 18

62 Advanced Power Quality Analysis Using PC s to Solve Harmonic Problems Section 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. 1

63 For most cases, four studies will be executed using the power 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). 2

64 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. 3

65 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 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. 4

66 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. 5

67 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. 6

68 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. 7

69 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 8

70 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 sequ: sequ: HARM SOURC sequ: sequ: 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 MI IMPEDANCE: J PER UNIT B/2: PER UNIT % SERIES COMP:.0 TO SHUNT(KVAR): 200. FROM SHUNT(KVAR): TRX SEC 4 FILTER FT 250 C N XLP IMPEDANCE: J.0396 OHMS/M FEET 3 TRX SEC 5 HARM SOURC FT 250 C N XLP IMPEDANCE: J.0396 OHMS/M FEET STATUS: EXISTING ============================================================================== SOURCE BUS THEVENIN EQUIVALENT IMPEDANCE: J OHMS Calculated From Largest 3-PHASE Fault Contribution ============================================================================== 9

71 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 TRX SEC IMPEDANCE: J 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. 10

72 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 CONSTANT Z LOAD 5 HARM SOURC CONSTANT Z LOAD 5 HARM SOURC CONSTANT I LOAD *** SOLUTION COMMENTS *** SOLUTION PARAMETERS PER UNIT DRIVING VOLTAGE : 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>> 11

73 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 = LOAD BUS: 1 UTILITY DESIGN VOLTAGE: LOAD VOLTAGE: %VD: VOLTAGE ANGLE:.0 DEGREES LOAD TO: 2 TRX PRI FEEDER AMPS: 2 VOLTAGE DROP: %VD: -.07 PROJECTED POWER FLOW: 814. KW KVAR KVA PF:.56 LEADING LOSSES THRU FEEDER: 1. KW KVAR 400. KVA LOAD FROM: **** SOURCE FEEDER AMPS: 2 VOLTAGE DROP: 0. %VD:.00 PROJECTED POWER FLOW: 814. KW KVAR KVA PF:.56 LEADING LOSSES THRU FEEDER: 0. KW 0. KVAR 0. KVA LOAD BUS: 5 HARM SOURC DESIGN VOLTAGE: LOAD VOLTAGE: %VD: 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 KVAR 12

74 To exit the viewing mode and return to the Main Menu, press F10 and the program will ask whether or not you want to exit. Press D(on't), then Enter, and the program will return to the Main Menu. D3. Execute the Frequency Scan For Resonance Study... The next study to be performed is the frequency scan for resonance which does not rely on the data generated in the two previous studies. This study does not take harmonic sources into consideration, rather it injects a 1 per unit current into the system in order to reveal the system's characteristic resonance points. 13

75 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. 14

76 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. 15

77 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. 16

78 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. 17

79 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. 18

80 Enter the data for this screen as shown below. Notice that in the Define 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. 19

81 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. 20

82 Press F1: Continue to view the frequency scan for resonance report below. Frequency Scan Criteria Text Output 21

83 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 22

84 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 P A S S I V E F I L T E R D A T A BUS VOLTAGE R (OHM) JXL (OHM) -JXC (OHM) ============================================================================== 4 FILTER POS SEQ ZERO SEQ HARM SOURC POS SEQ ZERO SEQ

85 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 P-KA: TYPE: UTILITY 1P-KA: POS SEQUENCE IMPEDANCE (100 MVA BASE) J PER UNIT MOTOR 5 HARM SOURC TYPE: IND. MOTOR KW/HP: RPM: POS SEQUENCE IMPEDANCE (100 MVA BASE) J 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 IMPEDANCE: J PER UNIT B/2: PER UNIT % SERIES COMP: TO SHUNT(KVAR): 200. FROM SHUNT(KVAR): 0. 3 TRX SEC 4 FILTER C N XLP POS seq Z J.0396 OHMS/M FEET J PU 24

86 T R A N S F O R M E R D A T A 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 TRX SEC YG POS SEQ Z J PERCENT J 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 userdefined steps, up to and including the maximum selected frequency. For the purposes of this illustration, the middle frequencies are omitted. 25

87 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 illustrated below. 26

88 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. 27

89 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. 28

90 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. 29

91 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. 30

92 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. 31

93 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. 32

94 Advanced Power Quality Analysis Using PC s to Solve Harmonic Problems Section 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: Distortion Calculations(386). 1

95 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. 2

96 Press F1: Continue and the Enter Project Title Lines window will appear. Enter title lines for the distortion calculation report as shown below. 3

97 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. 4

98 When all of the buses are selected, press F9: Execute, and the Select Branch Flow Records screen illustrated below will appear. 5

99 In this screen, you select the branches to be included in graphical output 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. 6

100 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. 7

101 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 8

102 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 shown below. Select F1: Continue to continue. Important Features of the Distortion Calculation Report 9

103 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 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 10

104 H A R M O N I C S O U R C E BUS: 5 HARM SOURC VOLTAGE: ID:SKM SIX PULSE KVA: ORDER MAGNITUDE ANGLE ORDER MAGNITUDE ANGLE ORDER MAGNITUDE ANGLE ============================================================================== H A R M O N I C S O U R C E I N D E X T A B L E HARMONIC SOURCES HAVE BEEN FOUND AND INJECTED FOR EACH OF THE FOLLOWING HARMONIC ORDERS

105 P A S S I V E F I L T E R D A T A BUS VOLTAGE R (OHM) JWL (OHM) -JWC (OHM) ============================================================================== 4 FILTER POS SEQ ZERO SEQ HARM SOURC POS SEQ ZERO SEQ 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 P-KA: TYPE: UTILITY 1P-KA: POS SEQUENCE IMPEDANCE (100 MVA BASE) J PER UNIT MOTOR 5 HARM SOURC TYPE: IND. MOTOR KW/HP: RPM: POS SEQUENCE IMPEDANCE (100 MVA BASE) J PER UNIT 12

106 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 IMPEDANCE: J PER UNIT B/2: PER UNIT % SERIES COMP: TO SHUNT(KVAR): 200. FROM SHUNT(KVAR): 0. 3 TRX SEC 4 FILTER C N XLP POS seq Z J.0396 OHMS/M FEET J PU 3 TRX SEC 5 HARM SOURC C N XLP POS seq Z J.0396 OHMS/M FEET J PU T R A N S F O R M E R D A T A 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 TRX SEC YG POS SEQ Z J PERCENT J PER UNIT 13

107 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 TRX PRI $ TRX SEC $ FILTER $ HARM SOURC $ 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 $ TRX SEC $ FILTER $ HARM SOURC $

108 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 TRX PRI 3 TRX SEC TRX SEC 4 FILTER TRX SEC 5 HARM SOURC Harmonic Voltage Spectrum Report 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: ============================================================================== HARMONIC HARMONIC PHASE DISTORTION IEEE-519 ORDER VOLT ANGLE PERCENT LIMIT ============================================================================== $ $

109 ++SUMMARY VOLTAGE V_RMS V_TIF V_THD(%) IEEE-519 LIMIT $ 5.0 $ INDICATES A VIOLATION OF IEEE STD 519 LIMITS FOR VOLTAGE Harmonic Current Spectrum Report 16

110 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 ============================================================================== SUMMARY VOLTAGE: I_RMS: 1.97 IT: K: I_THD(%): $ INDICATES A VIOLATION OF IEEE STD 519 LIMITS FOR CURRENT 17

111 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 ==============================================================================

112 ++SUMMARY CAPACITOR RATED VOLTAGE: (L-N) V_RMS: V_CREST: I_RMS: KVA: % V_RMS: %V CREST: % I: % KVA: LIMIT: 110.0% LIMIT: 169.7% LIMIT: 180.0% LIMIT: 135.0% Warning Message $ INDICATES A VIOLATION OF IEEE STD 519 LIMITS FOR CURRENT 19

113 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. 20

114 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. 21

115 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. 22

116 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. 23

117 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. 24

118 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. 25

119 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. 26

120 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 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. 27

121 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. 28

122 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. 29

123 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 data in this window to match that below. 30

124 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. 31

125 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. 32

126 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. 33

127 Press F6: Filter or Capacitor to access the interactive filter design screen, and edit the capacitor data to match the singletuned filter data shown below. 34

128 The capacitor is now tuned into a 5th harmonic order singletuned 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. 35

129 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. 36

130 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 reexecuted 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 frequency scan report name SCAN becomes SCAN_FLT in the new case, and so on for the other studies. 37

131 Compare Old and New Graphical Output Results 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. 38

132 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. 39

133 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. 40

134 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. 41

135 Notice that the large resonance peak at the sixth harmonic order has been reduced from 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. 42

136 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. 43

137 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. 44

138 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. 45

139 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. 46

140 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. 47

141 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. 48