Harmonic Estimator Basic

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Harmonic Estimator Report - One Line

Project Name Project #1 Prepared byEnd User Date preparedDistributor email of preparernotesversion 031001P Notes:

PCC is a Point of Common CouplingA "buffered drive" is one that has a DC Link ChokeA "xfmr" is a transformerAll of the values are recalculated when cell data is entered

Source60 Hz Linear Load 1 on utility xfmr (hp+kW)

0 total hp motor loadPCC1 PCC2 PCC3 + 0 total kW resistive loadPCC at utility xfmr PCC at user xfmr PCC at distribution panel

Linear Load 2 on user xfmr (hp+kW)100 feet 1 50 feet 2 0 total hp motor load

Utility feet between User feet between Distribution + 0 total kW resistive loadTransformer utility xfmr Transformer user xfmr and Panelor Generator and user xfmr distribution panel 6 pulse unbuffered drive without line reactor

50000 kVA 1 1500 kVA 2 0 total hp8.00 %Z 1 5.75 %Z 2 0 feet to panel

13800 Vsec 1 460 Vsec 2 460 Vsec 3 6 pulse buffered drive without line reactor- OR - 0 Isc 1 - OR - 0 Isc 2 0 total hp

at PCC1 at PCC2 at PCC3 0 feet to panel2092 Irated 1 1883 Irated 2 6 pulse buffered drive with 3% line reactor

26149 Isc 1 32743 Isc 2 26237 Isc 3 0 total hp808.3 L, uH 1 21.5 L, uH 2 5.3 L, uH 3 0 feet to panel

1.0 K-factor 1.0 K-factor 6 pulse buffered drive with 5% line reactor0.0 % thermal rating 0.0 % thermal rating 0 total hp0.0 Irms harmonics 0.0 Irms harmonics 0.0 Irms harmonics 0 feet to panel0.0 Irms fundamental 0.0 Irms fundamental 0.0 Irms fundamental 6 pulse buffered drive with basic harmonic filter0.0 Irms total 0.0 Irms total 0.0 Irms total Requires additional engineering 0 total hp

0 feet to panel26148.9 Isc/Iload 32742.9 Isc/Iload 26236.9 Isc/Iload 12 pulse buffered drive with auto xfmr

0.0 % V(THD) 0.0 % V(THD) 0.0 % V(THD) 0 total hp0.0 % I(TDD) 0.0 % I(TDD) 0.0 % I(TDD) 0 feet to panel

YES IEEE special YES IEEE special YES IEEE special 12 pulse buffered drive with iso xfmrYES IEEE general YES IEEE general YES IEEE general 0 total hpYES IEEE dedicated YES IEEE dedicated YES IEEE dedicated 0 feet to panelYES IEC YES IEC YES IEC 18 pulse buffered drive with auto xfmr

0 total hpCell Key: 0 feet to panel

data entry 18 pulse buffered drive with iso xfmr0 total hp

intermediate calc 0 feet to panel

harmonic results

Design Checks: (blank if no issues)

M

M

M

M

Mfilter

MIso

MAuto

MIso

MAuto

M

M

No

n-L

ine

ar

Dri

ve

Lo

ad

Please note that the information shown here is typical and does not constitute any guarantee of performance or measurement. Several outside factors can influence the harmonics measured on a power system, including other equipment within the plant and other equipment in neighboring plants. This can include, but is not limited to, drives, varying loads and/or other factory equipment. The calculated current and voltage harmonics shown in this report are for estimation purposes only.

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Harmonic Estimator Report - Tutorial

version 031001P

Welcome to the Rockwell Automation Harmonic Estimator Report program.

Below you will find the information you need to start using this program. There are three goals to this program:

1. To estimate the harmonics created by adjustable speed AC motor drivesoperating at a user's facility.2. To perform “what if” scenarios to determine what harmonic mitigation method needs to be used in order to meet the IEEE Std 519 recommended limits or other specific requirements.3. To provide a report to your customer showing the results of the analysis.

You will find that the program is easy to use, with an intuitive interface for filling in the required information.

Table of Contents for Worksheet Tabs:

One-LineThe main worksheet for inputting data and analyzing results.

Tutorial (You are reviewing this tab right now.)An introduction to this Harmonic Estimator Report program with a typical example.

Notes & ToolsThis worksheet has additional information on each of the data entry cells, with notes and useful tools to help handle unique situations.

Report SummaryThis worksheet is a summary of the source, load and results data. It can be printed out as a single page summary for contractors, customers, and others.

Report TableA single page report that can be printed out, detailing theindividual harmonics at each of the Points of Common Coupling.

Report SpectrumA single page report that can be printed out, detailing the current and voltage spectrums at each of the Points of Common Coupling.

An Example

Following along with an example is always helpful to start.(You may want to print this worksheet out in order to more easily follow along.)

The diagram above is a simple one-line of this Harmonic Estimator Report.The items in green are the input data, and the items in yellow are the outputs.

Obtain the DataFirst, you need to obtain the needed data from your customer in order tofill in the green cells on the One-Line worksheet.

kV A%ZV sec

M

hpkW

usertrans former

linear loadson user

trans former

M

Drive

hp

A C

A C

non-linearload

kV A%ZV sec

utilitytrans former

P C C 1I(T H D)V (T H D)



d is tr ibutionpanel

c ab lelength

c ab lelength

c ab lelength

M

hpkW

linear loadson utility

trans former

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Any analysis is only as good as the data entered.

Suppose your customer is operating on a 60Hz power grid system.He has a plant fed by the utility with 4160Vac at 3600Asc.This feed travels 300 feet to a panel. 1000kW of linear type load equipment is connected at this panel.It also feeds the primary of a 500kVA, 4%, 480Vac transformer.Three 125hp 6-pulse buffered drives are connected to the secondary of this transformer, along with five 20hp motors that are running across the line.

What harmonics can be expected at the connection point to the utility?What harmonics can be expected at the secondary of the 500kVA transformer?Will the customer meet IEEE 519 at either transformer secondary? If not, what can be done to meet IEEE 519 at both transformer secondaries?When operating from a 1750kW generator, will it meet IEEE 519?

To work out this example, go to the worksheet tab "One-Line" and open it.Then, type the following information in the green cells.

Enter the DataNow, fill in the customer information in cells C6 to C9 and J6 to J8.This helps you keep track of what situation is being analyzed.You will see that defaults exist in the green cells.

At cell B17, fill in 60 for the system frequency. 60 Hz

At cell B26, fill in 0 since the bottom three lines of data will be filled in. 0 kVA 1At cell B27, fill in 8 for a typical impedance at this voltage level from the utility. 8.00 %Z 1At cell B28, fill in 4160 for the secondary voltage from the utility. 4160 Vsec 1At cell B29, fill in 3600 for the short circuit current available from the utility. 3600 Isc 1

At cell D22, fill in 300 for the distance between the first and second transformer. 300 feet 1

At cell F26, fill in 500 for the kVA of the second transformer. 500 kVA 2At cell F27, fill in 4 for the impedance of the second transformer. 4.00 %Z 2At cell F28, fill in 480 for the secondary voltage of the second transformer. 480 Vsec 2At cell F29, keep this blank since the top three lines of data are filled in. 0 Isc 2

At cell H22, keep this at 0 since we don't have any information on this. 0 feet 2

At cell P18, keep this at 0 since we don't have any information on this. 0 total hp motor loadAt cell P19, fill in 1000 for the 1000kW of linear load on the first transformer. 1000 total kW resistive load

At cell P22, fill in 100 for the 5x20hp motors on the second transformer. 100 total hp motor loadAt cell P23, keep this at 0 since we don't have any information on this. 0 total kW resistive load

At cell S29, fill in 375 for the 3x125hp 6-pulse buffered drives also on the second transformer. 375 total hpAt cell S30, keep this at 0 since we don't have any information on this. 0 feet to panel

All of the other "Non-Linear Drive Load" green cells should have 0 in them or are blanksince we don't have any information on any other drives in the system.

That's all you have to enter!

Analyze the ResultsNow, lets analyze what the results are.

First, notice that the data in the blue and yellow cells for PCC2 and PCC3 are the same except for F33 and J33 (the circuit inductance) since J33 is calculated fromcell H22 which is the distance between PCC2 and PCC3.

Next, notice that there are no red messages under the "Design Checks" area (cell B48)indicating that there are no overloads or other problems. See Notes & Tools section A4 for more detail.

At PCC1, the secondary of the utility feed or transformer, we have the following information: (cells B31 to B46)at PCC1

288 Irated 1 rated current for the transformer3600 Isc 1 short-circuit current for the transformer

1769.8 L, uH 1 equivalent inductance for the transformer1.2 K-factor the required K-factor rating for the transformer if it is not to be derated

69.1 % thermal rating present % thermal rating, if transformer is rated at K-114.4 Irms harmonics Iharm, or harmonic current

197.1 Irms fundamental Ifund, or fundamental current197.6 Irms total Itotal, or total rms current

18.3 Isc/Iload ratio of Isc to Ifund

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2.8 % V(THD) total harmonic distortion in the voltage7.3 % I(TDD) total harmonic distortion in the current

NO IEEE special does not meet IEEE 519 for special circuitsNO IEEE general does not meet IEEE 519 for general circuitsNO IEEE dedicated does not meet IEEE 519 for circuits dedicated to non-linear loadsYES IEC meets IEC for harmonic content

So, in answer to our question, NO, it does not meet IEEE 519 at PCC1.

How about at PCC2, the secondary of the second transformer? (cells F31 to F46)at PCC2

601 Irated 2 rated current for the transformer15036 Isc 2 short-circuit current for the transformer

48.9 L, uH 2 equivalent inductance for the transformer3.7 K-factor the required K-factor rating for the transformer if it is not to be derated

92.0 % thermal rating present % thermal rating, if transformer is rated at K-1124.4 Irms harmonics Iharm, or harmonic current 505.6 Irms fundamental Ifund, or fundamental current520.7 Irms total Itotal, or total rms current

29.7 Isc/Iload ratio of Isc to Ifund8.5 % V(THD) total harmonic distortion in the voltage

24.6 % I(TDD) total harmonic distortion in the currentNO IEEE special does not meet IEEE 519 for special circuitsNO IEEE general does not meet IEEE 519 for general circuitsNO IEEE dedicated does not meet IEEE 519 for circuits dedicated to non-linear loadsNO IEC does not meet IEC for harmonic content

Similar information. Again, NO, it does not meet IEEE 519 at PCC2.

Going to Report Table and to Report Spectrum worksheet tabs, you will see the harmonics thatwould be present in tabular and graphical form for this system configuration.

What-if ScenariosNow, you can perform some "what-if" scenarios, trying different types of drives, or combination of drives,in order to be able to meet IEEE 519 at PCC1 and PCC2.

What if we changed the 3x125hp 6-pulse buffered drives to 18-pulse drives using an auto-transformer?Return to the One-Line worksheet tab and do the following.

At cell S29, fill in 0 to remove the 6-pulse buffered drives.At cell S47, fill in 375 for the 3x125hp 18-pulse drives.

Now, at PCC1, we have:at PCC1

288 Irated 1 This is the same3600 Isc 1 This is the same

1769.8 L, uH 1 This is the same1.0 K-factor The K-factor dropped due to the drop in Iharm

68.5 % thermal rating There is less loading on the transformer due to the drop in Iharm2.1 Irms harmonics Note how the harmonic current dropped from 14.4A to 2.1A!

197.1 Irms fundamental The fundamental current remained the same for the same load.197.1 Irms total The total current dropped due to the drop in Iharm

18.3 Isc/Iload This is the same0.6 % V(THD) V(THD) dropped from 2.8% to 0.6%1.1 % I(TDD) I(TDD) dropped from 7.3% to 1.1%

YES IEEE special It meets IEEE 519 for special circuitsYES IEEE general It meets IEEE 519 for general circuitsYES IEEE dedicated It meets IEEE 519 for dedicated circuitsYES IEC It meets IEC for harmonic content

This time, we do meet IEEE 519 at this point of common coupling.

And at PCC2 we have:at PCC2

601 Irated 2 This is the same15036 Isc 2 This is the same

48.9 L, uH 2 This is the same1.1 K-factor The K-factor dropped due to the drop in Iharm

84.5 % thermal rating There is less loading on the transformer due to the drop in Iharm18.4 Irms harmonics Note how the harmonic current dropped from 124.4A to 18.4A!

505.6 Irms fundamental The fundamental current remained the same for the same load.505.9 Irms total The total current dropped due to the drop in Iharm

29.7 Isc/Iload This is the same1.9 % V(THD) V(THD) dropped from 8.5% to 1.9%3.6 % I(TDD) I(TDD) dropped from 24.6% to 3.6%

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YES IEEE special It meets IEEE 519 for special circuitsYES IEEE general It meets IEEE 519 for general circuitsYES IEEE dedicated It meets IEEE 519 for dedicated circuitsYES IEC It meets IEC for harmonic content

We now meet IEEE 519 at this location.IEEE 519 is met in this configuration because the linear loads were included in the calculations.

The next scenario is with power being supplied by a generator.

Go to the "Notes & Tools" worksheet tab and follow the instructions in section A2f.Fill in 1750 for the kW rating of the generatorFill in 0.80 as a typical pf rating for the generatorFind 2188 as the calculated kVA rating of the generator.

Now, go to the One-Line worksheet tab.At cell B26, fill in 2188 for the kVA of the generator 2188 kVA 1At cell B27, fill in 16 as a typical subtransient reactance for a generator 16.00 %Z 1

Normally this information is on the nameplate of the generator. 4160 Vsec 1At cell B28, keep 4160 as the voltage - OR - 0 Isc 1At cell B29, fill in 0 for the short circuit current of the generator.

What has changed at PCC1?at PCC1

304 Irated 1 Changed due to generator parameters1898 Isc 1 Changed due to generator parameters

3356.8 L, uH 1 Changed due to generator parameters1.0 K-factor No change

65.0 % thermal rating Changed due to generator parameters2.1 Irms harmonics No change

197.1 Irms fundamental No change197.1 Irms total No change

9.6 Isc/Iload Changed due to generator parameters1.2 % V(THD) Slight increase from 0.6% to 1.2%1.1 % I(TDD) No change

YES IEEE special No changeYES IEEE general No changeYES IEEE dedicated No changeYES IEC No change

So, it still meets IEEE 519 for all cases at PCC1.

What has changed at PCC2?at PCC2

601 Irated 2 No change15036 Isc 2 No change

48.9 L, uH 2 No change1.1 K-factor No change

84.5 % thermal rating No change18.4 Irms harmonics No change

505.6 Irms fundamental No change505.9 Irms total No change

29.7 Isc/Iload No change2.5 % V(THD) Slight increase from 1.9% to 2.5%3.6 % I(TDD) No change

YES IEEE special No changeYES IEEE general No changeYES IEEE dedicated No changeYES IEC No change

It still meets IEEE 519 for special, general and dedicated circuits.

If this is acceptable, you can print copies of the reports for the different scenarios.If not, simply go back and change the type of drives being used in order to obtain the results needed.

Print the ReportsBefore you print the Report Summary, you can add some other notes in cell B55 of that report, if needed.

If the results are acceptable, print out a copy of the following worksheets for your records and for your customer:One-lineReport SummaryReport TableReport Spectrum

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Also, go back and change the numbers in cells B26 to B29 from the Generator to the data on theutility feed, and print another copy of the same worksheets for comparison purposes.

Most consultants only require a copy of the Report Summary sheet.

To make an electronic version of the reports:1 Hold Ctrl while you click on the tabs of the reports you want2 Go to Edit, select "Move or Copy Sheet…"3 In the "Move or Copy" window, for "To book", select "(new book)"4 Check the box at the bottom for "Create a copy"5 Click "OK"6 Save the new workbook under a new name7 You can then email that workbook to whoever needs an electronic version of the reports

The file size is about 73KB.

That's all there is to it!

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Harmonic Estimator Report - Notes & Tools

version 031001P

It is recommended that you first create and print a baseline of the existing installation system before additional drivesare added to it. You may find significant harmonics may exist even without the new drives.

This worksheet contains additional information on the data used in the One-Line, as well as various tools(mini spreadsheets) to help with calculations.

You may want to print a copy of these notes & tools for reference as you work through your first few systems.

NOTE:A green cell allows you to input information. All other cells are locked. You may tab from input cell to input cell.

A blue cell gives you calculated intermediate results, useful in an analysis.

A yellow cell gives you calculated harmonic results and harmonic compliance information

SectionA Go to the worksheet tab labeled "One-Line".

A1 Fill in the following information for the report header.Project Name name of project or order numberEnd User name of end userDistributor name of distributor working with end usernotes useful for naming various trial runs

Prepared by your nameDate prepared The date you worked on this. This date will not change when printed.email of preparer your email address for the customerversion The version number of this program is shown for reference.

NOTE: you may want to have your computer video monitor set for 1024 x 768, and set the excelsheet to 75% in order to see all of the sources and loads on the screen.The report header information will be off the screen.If you want an entry to be blank, enter a single quote '.

A2 Fill in the information on the Utility Transformer feeding the user system.

60 Hz "Hz" is the line frequency of the power system, typically 50 or 60Hz

A2a If there is a Utility Transformer ahead of the User Transformer, fill in the data about the Utility Transformer:

4000 kVA 1 "kVA 1" is the kVA rating of the utility transformer8.00 %Z 14160 Vsec 1 "Vsec 1" is the secondary line-to-line voltage out of the utility transformer or source

- OR - 0 Isc 1 keep this at 0

A2b If the system does not have a Utility Transformer, use the following defaults:

50000 kVA 18.00 %Z 1

13800 Vsec 1- OR - 0 Isc 1

A2c If the utility supplied only Vsec 1 and Isc 1 information for the feed to the user, use the following to fill in for the Utility Transformer:

0 kVA 1 keep this at 08.00 %Z 1 default = 6.00 for voltages less than 600v, 8.00 for voltages greater than 600v

4160 Vsec 1 information supplied- OR - 3600 Isc 1 information supplied

"%Z 1" is the % impedance rating of the utility transformer, and it must be >0


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If data other than 0 is in the box for kVA 1, there will be design check problems showing up, and the message of "make kVA1=0" will appear in the box for "L, uH 1".

1500 kVA 18.00 %Z 12300 Vsec 1

- OR - 0 Isc 1

If Isc1 is filled in, that Isc will also be seen in blue cell C32.

A2d Here is a tool to determine kVA if you know the other three parameters:

2075 kVA 18.00 %Z 1 default = 6.00 for voltages less than 600v, 8.00 for voltages greater than 600v

4160 Vsec 13600 Isc 1

NOTE: some value for %Z is needed, and it must be >0

A2e Here is a tool to determine %Z if you know the other three parameters:

1500 kVA 15.78 %Z 14160 Vsec 13600 Isc 1

A2f If the feed is from a generator, use the kW rating of the generator, its pf, impedance and its output voltage to fill in the following information. If the kVA rating of the generator is given,use that number for kVA1.

1750 kW (from generator nameplate data)0.80 pf of generator (typically 0.80)2188 kVA of generator

Now, fill in the following for the Utility Transformer that is simulating a generator:

2188 kVA 1 (from the calculation above)16.00 %Z 1 (typical subtransient reactance, unless you have nameplate data)

xxx Vsec 1 (use output voltage from generator nameplate data)- OR - 0 Isc 1 keep this at 0

A3 Fill in the information on the User Transformer feeding the drives.

"feet to xfmr 1" is the approximate length of cable connecting the user transformer to the utility transformer

The user transformer is the transformer closest to the drive system.

A3a If there is a User Transformer ahead of the drive system, fill in the data about the user transformer:

4000 kVA 2 "kVA 2" is the kVA rating of the user transformer8.00 %Z 24160 Vsec 2 "Vsec 2" is the secondary line-to-line voltage out of the user transformer


A3b If the drive is powered directly by a generator, use the kW rating of the generator, its pf, impedance and its output voltage to fill in the following information

1000 kW (from generator nameplate data)0.80 pf of generator (typically 0.80)1250 kVA of generator

Now, fill in the following for the User Transformer that is simulating a generator:

1250 kVA 2 (from the calculation above)16.00 %Z 2 (typical subtransient reactance, unless you have nameplate data)

xxx Vsec 2 (use output voltage from generator nameplate data)

This means that data should be filled in either the top three boxes or in the bottom three boxes.Do not enter data in both kVA 1 and in Isc 1.

"%Z 2" is the % impedance rating of the user transformer, and it must be >0

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And, for the Utility Transformer data, fill in the following:

50000 kVA 18.00 %Z 1

13800 Vsec 1- OR - 0 Isc 1

A3c

A4 NOTE: Design checks are located in the One-Line diagram in the lower left of the screen, below B48.They refer to the following conditions that need to be corrected or known:

a. The kVA of the utility xfmr must be greater than the kVA of the user xfmr.b. If the Isc of user xfmr is greater than 65,000A,

c. If the total Irms or Ipk load on the utility xfmr is greater than its rating,

d. If the total Irms or Ipk load on the user xfmr is greater than its rating,

e. If the voltage at the distribution panel is less than 90% of Vsec 2,

A5 Fill in the information on each type of non-linear drive load connected to the distribution panelUse the following tools to make conversions of data.

"total hp" is the total horsepower load on the drive(s). 460 is the line voltage used by these drives (from One-Line F28)

144 A 300 kW 100 hp 100 hp124.4 hp 374.0 hp 80.2 kW 92.2 kVA

(see section E2 for the parameters used in these conversions)

To convert meters to feet: To convert feet to meters:200.0 meters 328.0 feet656.0 feet 100.0 meters

A6 For the 6 pulse buffered drive with basic harmonic filter, please realize that the impedance feedingthis filter must be between 1.5% and 6%. If the user transformer and cable has an impedance thatis less than this, additional line reactors need to be added in front of the filter in order for it to

0 hp of drive (from the One-Line worksheet tab)0.0 uH, for minimum of 1.5% impedance0.0 uH, for maximum of 6.0% impedance

26.9 uH, total impedance of drive transformer plus cable to panel and to drive

Note: impedance needs to be reduced

A7 Fill in the information on the linear loads connected to the utility and user transformer secondariesa. The hp load and the kW load are summed by the program.b. These loads are expected to be balanced three-phase loads.c. "hp" is the horsepower load, at 93% efficiency, 0.87 power factor. d. "kW" is the kilowatt load, at 100% efficiency, 1.00 power factor.

Use this for lighting loads.

If only the amp load is known the kW can be figured from:

"feet between user xfmr and distribution panel" is the approximate length of cable connecting the distribution panel to the user transformer

the user xfmr kVA rating must be reduced or the % Z must be increased to limit the short circuit current to 65,000A.

the load must be reduced or the kVA of the transformer must be increased.

the load must be reduced or the kVA of the user transformer must be increased.

the distance between the user xfmr and the distribution panel must be decreased or the load must be reduced.

To convert motor FLA to hp:

To convert kW to hp:

To convert hp to kW:

To convert hp to kVA:

"feet to panel" is the approximate length of cable connecting the drive to the distribution panel. If several drives of the same type have more than one length of cable, use the shortest cable as worst case.

perform as designed. NOTE: Additional engineering is required before this filter is used.

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Linear Load on utility xfmr Linear Load on user xfmr300 Aac 500 Aac

13800 Vsec 1 460 Vsec 27170 kW 398 kW

A8 The One-Line shows in the blue and yellow cells the results of the calculations on transformer information and harmonic distortion levels.

At PCC1and PCC2, given are Irated rated rms current of the xfmrIsc rated short circuit current of the xfmrL, uH inductance of the xfmr secondary, uH (resistance of transformer winding is considered to be 0)K factor K-factor rating for the transformer% thermal rating Itotal vs derated based on K-factor, if xfmr is rated K-1Irms harmonics the harmonic rms current in the secondaryIrms fundamental the fundamental rms current in the secondaryIrms total the total rms current in the secondary

Isc/Iload ratio of Isc to Irms fundamental at the xfmr% V(THD) voltage total harmonic distortion% I(TDD) current total demand distortionIEEE special if IEEE special current and voltage criteria are metIEEE general if IEEE general current and voltage criteria are metIEEE dedicated if IEEE dedicated current and voltage criteria are metIEC if IEC current criteria are met

A9 Note that I(TDD) = Irms harmonics / Irms fundamental (max)and that Irms total = sqrt((Irms harmonics)^2 + (Irms fundamental)^2))

If you know Itotal and the % I(TDD), you can find Iharm and Ifund from:1000 Itotal, A38.0 % I(TDD) or % I(THD)

355.2 Iharm, A934.8 Ifund, A

A10 At PCC3, given are Vsec 3 fundamental voltage at the distribution panel due to load

Isc rated short circuit current of the xfmrL, uH inductance of the xfmr secondary, uH

Irms harmonics the harmonic rms current at the panelIrms fundamental the fundamental rms current at the panelIrms total the total rms current at the panel

Isc/Iload ratio of Isc to Irms fundamental at the xfmr% V(THD) voltage total harmonic distortion% I(TDD) current total demand distortionIEEE special if IEEE special current and voltage criteria are metIEEE general if IEEE general current and voltage criteria are metIEEE dedicated if IEEE dedicated current and voltage criteria are metIEC if IEC current criteria are met

A11 Typically, the Point of Common Coupling (PCC) is at the point where the power into the plantis metered and where other customers are connected to the power grid.This is the location where the IEEE 519-1992 calls the PCC.

In this program, this could be at PCC1 or it could be to the left of the Utility Transformer.

The goal of clean power at the PCC is that one customer should not affect the powerthat another customer is also using due to processes or equipment connected within thefirst customer's plant.

If there is only one transformer between the drives and the meter to the plant, then use theUser Transformer for that, and then the PCC is at PCC1. The Utility Transformer wouldthen be the transformer that feeds power to multiple customers.If information on the Utility Transformer in unknown, use the defaults noted above in section A2b.

If there are two transformers between the drives and the meter to the plant, then use the User Transformer to feed the drives, and the Utility Transformer to feed the User Transformer. The PCC would then be located to the left of the Utility Transformer. The I(TDD) at the PCC would be equivalent to the I(TDD) at PCC1 for the Utility xfmr. The V(THD) at the PCC is unknown since the impedance of the feed to the Utility Transformer is unknown.

At times, a customer is interested in what harmonics exist within his own plant,

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harmonics that could affect other equipment running off of the same line. This is the reasonfor showing PCC1, PCC2 and PCC3.

A12 A single sheet printout of this worksheet can be made.

B Go to the tab labeled "Report Summary".This worksheet shows what a printout copy of the Report Summary will look like.

C Go to the tab labeled "Report Table".This worksheet shows what a printout copy of Report Table will look like.

D Go to the tab labeled "Report Spectrum".This worksheet shows what a printout copy of Report Spectrum will look like.

E Basic assumptions and terms used in the program

E1 The power lines are balanced, and do not contain pre-existing harmonics.The loads are balanced.

E2 These parameters can be modified by the preparer (fill in different data if known)Power factor of motors = 0.87 default = 0.87

Efficiency of motors = 0.93 default = 0.93

Power factor of drives = 0.95 default = 0.95

Efficiency of drives = 0.965 default = 0.965

Inductance/meter of cable = 0.35 uH/m default = 0.35

Power factor of kW linear loads = 1.00 default = 1.00

E3 A 75hp CT / 100hp VT drive was used as the basis for the harmonic simulations.The transformer secondaries and cables are considered to have zero resistance.

E4 Buffered DriveA "buffered" drive is one that has a DC Link Choke between the converter and DC bus caps.An "unbuffered" drive does not have a DC Link Choke.

E5 IEEE criteria (per IEEE Std 519-1992)In order to meet the IEEE criteria, there are voltage and current limits that must be met.The voltage limits can fall into one of three categories:

Special applications, that include hospitals and airportsGeneral systems, where typical industrial equipment is connectedDedicated systems, that is exclusively dedicated to the converter load

For each of these categories, the %V(THD) limits are as follows: (table 10.2 of the standard)Category max %V(THD)Special systems = 3%General systems = 5%Dedicated systems = 10%

The current limits fall into one of five categories based on the Isc/Iload ratio at the point of common coupling.

For each of these categories, the maximum harmonic currents in % of Ifund are as follows: (table 10.3 of the standard)Isc/Iload 2 to 10 11 to 16 17 to 22 23 to 34 35 to … I(TDD)<20 4.0 2.0 1.5 0.6 0.3 5.020 to <50 7.0 3.5 2.5 1.0 0.5 8.050 to <100 10.0 4.5 4.0 1.5 0.7 12.0100 to <1000 12.0 5.5 5.0 2.0 1.0 15.01000 and higher 15.0 7.0 6.0 2.5 1.4 20.0

The Isc/Iload ratio, also known as the SCR for short-circuit ratio, is the ratio of the rated short-circuit current of the feedto the fundamental current of the load on that feed.

Even harmonics are limited to 25% of the odd harmonic limits above.The calculations check these limits at PCC1, PCC2 and PCC3.For the IEEE calculations, harmonics from the 2nd to the 50th are used.

E6 In order to determine whether the drive configuration meets IEEE 519, this program can compare the individual harmonics to the above table in addition to the Current Total Demand Distortion, I(TDD), and the Voltage Total Harmonic Distortion, V(THD), or it cando only the I(TDD) and (V(THD) comparisons to determine pass/fail based upon the following flag being set:

IEEE test flag 0 default = 00 means comparisons of I(TDD) and V(THD) only1 means comparisons of the individual harmonic currents, I(TDD) and V(THD)

E7 IEC criteria (per IEC 61000-3-12)

Typically, drives rated <5hp are unbuffered.

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This standard limits the harmonic currents produced by equipment connected to the public low-voltagesystems with input current less than or equal to 75A per phase and subject to restricted connection.At this point in time (March 2002), this is not released and is subject to change.

The current limits for balanced three-phase equipment is based on the Rsce ratio(Rsce is the same as the Isc/Iload ratio used by IEEE, the short circuit to load current ratio)at the point of common coupling, and looks at the harmonic currents at the5th, 7th, 11th, 13th as well as the THD and the PWHD.

max %Rsce 5th 7th 11th 13th THD PWHD33 to <66 10.7 7.2 3.1 2 13 2266 to <120 14 9 5 3 16 25120 to <250 19 12 7 4 22 28250 to <350 31 20 12 7 37 38350 and higher 40 25 15 10 48 45

For the IEC calculations, harmonics from the 2nd to the 40th are used.Voltage harmonics are not limited by IEC.Linear interpolation between successive Rsce values is permitted.

E8 THDThe Total Harmonic Distortion (THD) number is the square root of the sum of the squares of the harmonics being measured, from the 2nd harmonic to the highest harmonic of interest, divided by the fundamental value.This calculation is the same for currents and for voltages.

I(THD) = (sqrt(sumsq(In))/(Ifund) n = 2 to 50 for IEEEn = 2 to 40 for IECIn = nth current harmonicIfund = fundamental current

V(THD) = (sqrt(sumsq(Vn))/(Vfund) n = 2 to 50 for IEEEVn = nth voltage harmonicVfund = fundamental voltage

note that:Iharm = sqrt(sumsq(In))I(THD) = Iharm / IfundIrms total = sqrt((Iharm)^2 + (Ifund)^2)

E9 TDDThe calculation for the Total Demand Distortion (TDD) is the same as for the THD,however, this measurement takes into account the maximum load expected overa 15 minute to 30 minute window instead of a simple snapshot in time. Typically, this takes into account any linear loads attached to the system.This is used for the calculations for meeting the IEEE criteria.

So, in this program, I(TDD) = I(THD).

E10 PWHDThe Partial Weighted Harmonic Distortion (PWHD) number is the square root of the sumof the harmonic number times the square of the harmonic current divided by the fundamental current,from the 14th to the 40th harmonic.This is used for the IEC criteria.

PWHD = (sqrt(sum(n*(In/Ifund)^2))) n = 14 to 40 for IECIn = nth current harmonicIfund = fundamental current

E11 PCCThe Point of Common Coupling. See discussion above under A11

E12 K-FactorThe K-factor is a term used to help determine the additional eddy current heating a transformerwill have due to harmonic currents.

K-Factor = (sum of (n*In)^2) / (sum of (In)^2)

A transformer needs to be derated to the following level:

derating = Irated *sqrt((1+Rec-r) / (1+k*Rec-r))

This gives the maximum current rating of the transformer feeding a load containing the harmonics used to calculate the K-Factor.

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Harmonic Estimator Report - Summary

Project Name Project #1 Prepared by 0End User 0 Date prepared ###Distributor 0 email of preparer 0notes 0version 031001P

IECPCC location Voltage THD, % Current TDD, % Isc/Iload special general dedicated compliancePCC1 0.0 0.0 26148.9 YES YES YES YESPCC2 0.0 0.0 32742.9 YES YES YES YESPCC3 0.0 0.0 26236.9 YES YES YES YES

DataSources Hz kVA %Z Vsec Isc K-factor Irated, rms Iharm Ifund ItotalUtility xfmr 60 50000 8.00 13800 1.0 2092 0 0 0User xfmr 1500 5.75 460 1.0 1883 0 0 0

feetdistance between utility xfmr and user xfmr 100distance between user xfmr and distribution panel 50

Total hp Total kW feet to panelLinear Load 1 0 0.0Linear Load 2 0 0.06p unbuffered 0 0.0 06p buffered 0 0.0 06p 3% line react 0 0.0 06p 5% line react 0 0.0 06p w/ filter 0 0.0 012p auto parallel 0 0.0 012p iso series 0 0.0 018p auto parallel 0 0.0 018p iso series 0 0.0 0

Footnotes1.

2. Use the compliance information only for the category of interest required for the application.3. Unless described as "unbuffered", all of the drives have a DC Link Choke.

Additional Notes(additional notes as required)

Results 1 IEEE compliance 2

Load Types 3

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Harmonic Estimator Report - Table

Project Name Project #1 Prepared by 0End User 0 Date prepared ###Distributor 0 email of preparer 0notes 0version 031001P Total Irms at PCC1 = 0 Arms

Total Irms at PCC2 and PCC3 = 0 Arms

Harmonic Spectrum

1 60 0.000 100.000 0.000 100.000 0.000 100.0002 120 0.000 0.000 0.000 0.000 0.000 0.0003 180 0.000 0.000 0.000 0.000 0.000 0.0004 240 0.000 0.000 0.000 0.000 0.000 0.0005 300 0.000 0.000 0.000 0.000 0.000 0.0006 360 0.000 0.000 0.000 0.000 0.000 0.0007 420 0.000 0.000 0.000 0.000 0.000 0.0008 480 0.000 0.000 0.000 0.000 0.000 0.0009 540 0.000 0.000 0.000 0.000 0.000 0.000

10 600 0.000 0.000 0.000 0.000 0.000 0.00011 660 0.000 0.000 0.000 0.000 0.000 0.00012 720 0.000 0.000 0.000 0.000 0.000 0.00013 780 0.000 0.000 0.000 0.000 0.000 0.00014 840 0.000 0.000 0.000 0.000 0.000 0.00015 900 0.000 0.000 0.000 0.000 0.000 0.00016 960 0.000 0.000 0.000 0.000 0.000 0.00017 1020 0.000 0.000 0.000 0.000 0.000 0.00018 1080 0.000 0.000 0.000 0.000 0.000 0.00019 1140 0.000 0.000 0.000 0.000 0.000 0.00020 1200 0.000 0.000 0.000 0.000 0.000 0.00021 1260 0.000 0.000 0.000 0.000 0.000 0.00022 1320 0.000 0.000 0.000 0.000 0.000 0.00023 1380 0.000 0.000 0.000 0.000 0.000 0.00024 1440 0.000 0.000 0.000 0.000 0.000 0.00025 1500 0.000 0.000 0.000 0.000 0.000 0.00026 1560 0.000 0.000 0.000 0.000 0.000 0.00027 1620 0.000 0.000 0.000 0.000 0.000 0.00028 1680 0.000 0.000 0.000 0.000 0.000 0.00029 1740 0.000 0.000 0.000 0.000 0.000 0.00030 1800 0.000 0.000 0.000 0.000 0.000 0.00031 1860 0.000 0.000 0.000 0.000 0.000 0.00032 1920 0.000 0.000 0.000 0.000 0.000 0.00033 1980 0.000 0.000 0.000 0.000 0.000 0.00034 2040 0.000 0.000 0.000 0.000 0.000 0.00035 2100 0.000 0.000 0.000 0.000 0.000 0.00036 2160 0.000 0.000 0.000 0.000 0.000 0.00037 2220 0.000 0.000 0.000 0.000 0.000 0.00038 2280 0.000 0.000 0.000 0.000 0.000 0.00039 2340 0.000 0.000 0.000 0.000 0.000 0.00040 2400 0.000 0.000 0.000 0.000 0.000 0.00041 2460 0.000 0.000 0.000 0.000 0.000 0.00042 2520 0.000 0.000 0.000 0.000 0.000 0.00043 2580 0.000 0.000 0.000 0.000 0.000 0.00044 2640 0.000 0.000 0.000 0.000 0.000 0.00045 2700 0.000 0.000 0.000 0.000 0.000 0.00046 2760 0.000 0.000 0.000 0.000 0.000 0.00047 2820 0.000 0.000 0.000 0.000 0.000 0.00048 2880 0.000 0.000 0.000 0.000 0.000 0.00049 2940 0.000 0.000 0.000 0.000 0.000 0.00050 3000 0.000 0.000 0.000 0.000 0.000 0.000

% THD 0.00 0.00 0.00 0.00 0.00 0.00

Harmonic Number

Frequency, Hz

% Irms at PCC1

% Vrms at PCC1

% Irms at PCC2

% Vrms at PCC2

% Irms at PCC3

% Vrms at PCC3

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Harmonic Estimator Report - Spectrum

Project Name Project #1 Prepared by 0End User 0 Date prepared ###Distributor 0 email of preparer 0notes 0version 031001P

Harmonic Data

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Harmonic Estimator Basic

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