caso estudio armonicos y correccion fp - fabrica

7/30/2019 Caso Estudio Armonicos y Correccion Fp - Fabrica

1/19

Harmonic Analysis and Power FactorHarmonic Analysis and Power Factor

Correction Evaluation Correction Evaluation

Plastic Creations Line 13Plastic Creations Line 13

Prepared by:

Electrotek Concepts, Inc.Knoxville, TNwww.electrotek.com

Wade EcklerPower Systems Engineer


2/19

Plastic Creations Line 13 Harmonics and Power Factor Correction Evaluation

ElectrotekConcepts, Inc. ii

- Table of Contents -

Executive Summary ______________________________________________________1

1.0 I ntroduction _________________________________________________________2

One Line Diagram ___________________________________________________________ 2

2.0 Field Measur ements at Newtown ________________________________________3

2.1 AC Drive Characteristics Roll 1 _________________________________________3

AC Drive Characteristics Roll 2 ______________________________________________ 4

2.2 AC Drive Characteristics Kneader B_____________________________________6

Overall Load Characteristics Line 13 __________________________________________ 7

2.3 Voltage Distortion Evaluations ___________________________________________ 9

3.0 Recommended Power Factor Correction _________________________________13

3.1 Summary of Reactive Power Requirements ________________________________ 13

4.0 Proposed F il ter Design _______________________________________________14

Appendix A: Low Vol tage Power Factor Correction Equipment Manuf acturers ____16


3/19


ElectrotekConcepts, Inc. 1

Executive Summary

The Plastic Creations in Newtown has a new Line 13 with ac variable frequency drives for

the calender line. The drives have high harmonic current levels but do not require the

level of power factor correction that dc drives require.

This evaluation characterizes the loads on Line 13. Power factor correction needs are

calculated and the impact of the existing capacitor bank (provides about 600 kvar of

compensation) is illustrated. The capacitor increases distortion levels at the 7th

and 11th

harmonics, resulting in overall voltage distortion levels exceeding 5% on the 480 volt

system. Although this should not cause problems for now, the distortion levels are likely

to be unacceptable with additional loading from Line 14. Also, the capacitor creates the

potential for magnified transient voltages if the utility switches capacitor banks on the

transmission system.

The capacitor should be converted into a tuned filter and it should be able to provide

power factor correction for the existing Line 13 (correction to a power factor of aboutunity) and should also be sufficient even after the addition of Line 14 (power factor

around 0.97). Specifications for the reactor to tune this bank are provided here.

480 Volt Bus

Tuned

Capacitor

Bank

Capacitor Bank:937.5 kvar600 volts

Inductors:0.046 mH per phaserms current rating = 15th harmonic current r775 amps

Circuit Brea480 Volt, 20

Proposed Filter Configuration for Line 13 and Line 14


4/19



1.0 Introduction

The Plastic Creations plant in Newtown has a new Line 13 with a dedicated transformer.

Line 13 includes ac variable frequency drives instead of the dc drives that are used onother Plastic Creations lines. This has a dramatic impact on the power factor

characteristics of the load. The ac drives have much better displacement power factor

(not as much compensation needed) but have significant harmonic distortion levels. The

measurements and recommendations presented in this report deal with the power factor

correction and filtering requirements for this line, including the impact of a future Line 14

with similar characteristics to Line 13.

One Line Diagram

Utility 13.8 kV Feeder

138 kV substation

3750 kVA, 7.0 %13.8 kV/480 volts

937.5 kvar600 volts

H110 Kneader13-2

Calender Controls(Protected by 24

UPS)

MCC7H22

H111Kneader

13-1

H112

Mixer

Grinders

CalenderHeaters

H113


5/19



2.0 Field Measurements at Newtown

Measurements were taken to characterize the ac drive loads and the overall load

characteristics for Line 13. The measurements also evaluated the impact of the existing

capacitor bank on distortion levels on the 480 volt system supplying Line 13.

2.1 AC Drive Characteristics Roll 1

The following waveforms and harmonic spectrums are typical for Roll 1. This is also

typical for Roll 3.

Event waveform/detail

Pre/Post-trigger at 02/25/98 11:32:34.312

CHA Amps

11:32:34.31 11:32:34.32 11:32:34.33 11:32:34.34 11:32:34.35 11:32:34.36 11:32:34.37 11:32:34.38

Amps

-150

-100

-50

0

50

100

150


Total RMS: 61.27 Amps

Total harmonic distortion: 32.52 Amps

Even contribution (H02-H50): 1.31 Amps

Odd contribution (H03-H49): 32.50 Amps

Pre/Post-trigger at 02/25/98 11:32:34.362

CHA Amps

THDabs H05 H10 H15 H20 H25 H30

Amps

0

10

20

30

40

50

60


6/19



AC Drive Characteristics Roll 2

The following waveforms and harmonic spectrums are typical for Roll 2. This is also

typical for Roll 4.


Timed event at 02/25/98 12:48:18.000

CHA A mps

12:48:18.000 12:48:18.005 12:48:18.010 12:48:18.015 12:48:18.020

Amps

-300

-200

-100

0

100

200

300






Timed event at 02/25/98 12:48:18.000

CHA A mpsTHDabs H05 H10 H15 H20 H25 H30

Amps

0

25

50

75

100

125


7/19



Example waveform and spectrum from BMI 3030

Roll 2 Current Waveform

0 10 20 30 40-200

-100

0

100

200

Time (mS)

Roll 2 Harmonic Characteristics

0 10 20 30 400

20

40

60

80

100

Frequency (H pu)

Freq :Fund :THD :TID :TD :

RMSh :RMSi :

RMSfh:

RMS :ASUM :TIF :IT :

189.578452.7698052.769847.27030101.286

101.286179.963454.67446051.9


8/19



2.2 AC Drive Characteristics Kneader B

The following waveforms and harmonic spectrums are typical for Kneader B. This is also

typical for Kneader A.


Snapshot event at 02/25/98 14:53:43.000

CHA A mps

14:53:43.000 14:53:43.005 14:53:43.010 14:53:43.015 14:53:43.020

Amps

-750

-500

-250

0

250

500

750







CHA A mps


Amps

0

50

100

150

200

250


9/19



Overall Load Characteristics Line 13

The following summarizes the overall load characteristics for Line 13. This includes the

ac drives characterized in the previous sections along with the calender heaters and other

loads that are part of the Line. This information can be used for evaluating harmonic filterand power factor correction requirements.

The table also illustrates the effect of the existing capacitor bank on the distortion levels

and the power factor. Note that the 7th

harmonic is significantly increased when the

capacitor bank is in service and the voltage distortion often exceeds 5%. The current

distortion increases to more than 30% with 20% at the 7th

harmonic. This is an indication

of the magnification at the 7th

harmonic component.

Current 1300-1800 amps 1300-1600 amps

Power 1.1-1.3 MVA 1.0-1.1 MVA

kvar 480-500 kvar 150-180 kvar lead

PF .88-.90 0.95

dPF .88-.91 0.99 lead

THDv 2.9-3.2 % 4.5-5.9 %

THDi 15-17 % 25-32 %

V5 1.9-2.0 % 2.5 %

I5 12-13 % 19 %

V7 1.8 % 3.2 %

I7 8-9 % 20 %

No Cap Bank with Cap Bank


10/19



The following waveform and harmonic spectrum represent typical load characteristics for

Line 13 (without the capacitor bank).

Line 13 Current Waveform

0 10 20 30 40-3000

-2000

-1000

0

1000

2000

3000

Time (mS)

Line 13 Current Harmonic Spectrum

0 3 6 9 12 150

250

500

750

1000

1250

1500

1750

Frequency (H pu)

Freq :Fund :THD :TID :TD :

RMSh :RMSi :

RMSfh:

RMS :ASUM :TIF :IT :

11529.8914.4941014.4941221.74401545.87

1545.871939.8985.7982132633


11/19



2.3 Voltage Distortion Evaluations

The following measurement results summarize the voltage distortion concerns at the 480

volt bus supplying Line 13.

Voltage Character ist ics withou t Capaci tor Bank

Typical voltage waveforms and spectrums are provided below without the capacitor bank

in service. The distortion is dominated by the 5th

harmonic component since that is the

highest current injection from the drive loads.


Total RMS: 464.93 Volts

Total harmonic distortion: 15.76 Volts

Even contribution (H02-H50): 2.68 Volts

Odd contribution (H03-H49): 15.54 Volts


CHA V olts


Volts

0

100

200

300

400

500



CHA Volts

15:48:40.00

15:48:40.01

15:48:40.02

15:48:40.03

15:48:40.04

15:48:40.05

15:48:40.06

15:48:40.07

Volts

-750

-500

-250

0

250

500

750


12/19



Voltage Character ist ics with Capaci tor Bank

Typical voltage waveforms and spectrums are provided below after the capacitor bank

was switched in. The capacitor creates a resonance between the 7th

and 11th

harmonics,magnifying both of these components. The voltage distortion levels are increased overall

and can exceed 5%. The highest distortion is typically at the 7th

harmonic with the

capacitor bank in due to the magnification.


Meter mode snapshot at 02/25/98 16:20:59.000

CHA V olts

16:20:59.000 16:20:59.005 16:20:59.010 16:20:59.015 16:20:59.020

Volts

-750

-500

-250

0

250

500

750


Total RMS: 473.33 Volts

Total harmonic distortion: 24.32 Volts

Even contribution (H02-H50): 0.59 Volts

Odd contribution (H03-H49): 24.33 Volts

Meter mode snapshot at 02/25/98 16:20:59.000

CHA V olts


Volts

0

100

200

300

400

500


13/19



Compar ison of Vol tage Character ist ics

The figure below shows the THD of the voltage on the Line 13 Main Bus and the values

of the 5th, 7

th, 11

th, and 13

thharmonic as percentages of the fundamental with the capacitor

bank on line and with it off line. The chart makes it easier to see how placing the

capacitor bank on line at the Line 13 Main Bus magnifies the 7th and 11th harmonics. The7

thharmonic is virtually non-existent, at 0.02% of the fundamental, with the capacitor

bank off line. The 11th

harmonic was measured at 0.75% without the capacitor banks.

After placing the capacitor banks on line, the 7th

increases to 3.73% and the 11th

increases

to 2.23% of the fundamental.

Line 13 Main Bus

0.00

1.00

2.00

3.00

4.00

5.00

6.00

THDv 5th 7th 11th 13th

Harmonic

VoltageDistortion(%)

No Caps

With Caps


14/19



Descr ipt ion of the Resonance Problem

The capacitor bank introduces a resonance between the 7th

and 11th

harmonics that

magnifies both of these components. The frequency scan below illustrates the voltage at

the 480 volt bus per amp injected by the drive loads with and without the capacitor bankin service.

Frequency Scan with and Without Capacitor Bank

0.00 3.00 6.00 9.00 12.00 15.00 18.00 21.00 24.00 27.000.0

0.1

0.2

0.3

0.4

Frequency (H pu)

This problem can be avoided by converting the capacitor bank into a tuned filter. The

frequency scan plots below show the effect of the tuned filter in preventing resonances

close to the characteristic harmonics of the drive loads (5th

and 7th).

Frequency Scan Showing Effect of Filter

0.00 3.00 6.00 9.00 12.00 15.00 18.00 21.00 24.00 27.000.0

0.1

0.2

0.3

0.4

Frequency (H pu)


15/19



3.0 Recommended Power Factor Correction

This section summarizes the power factor correction needs for the existing configuration

with Line 13 and estimates the impacts of a similar line (Line 14) in the future.

3.1 Summary of Reactive Power Requirements

The following table summarizes the load characteristics measured for Line 13 and shows

the impact of the 600 kvar of compensation on the power factor of the overall load. The

table also shows the effect of this capacitor bank if the load is doubled to include the effect

of Line 14 in the future.

The power factor with just Line 13 is corrected to unity with the existing capacitor bank.

With Line 14, the capacitor bank will correct the power factor to about 0.97 lagging when

both lines are running.

Line 13 Line 13 and Line 14

Transformer Size 3750 3750

Transformer Impedance 7% 7.00%

Peak Load (kVA) 1300 2600

Displacement Power Factor 0.9 0.9

Reactive Power (kvar) 567 1133

Real Power (kW) 1170 2340

Compensation (kvar) 600 600

Total Reactive Power with Compensation (kvar) -33 533

Power Factor with Compensation 1.00 0.97

Fifth Harmonic Current (%) 15% 15%

The capacitor should be configured as a tuned bank to prevent excessive distortion and

problems with magnification of capacitor switching transients. The next section gives

parameters for the tuning reactor.


16/19



4.0 Proposed Filter Design

Plastic Creations has already purchased a capacitor bank for power factor correction. The

capacitor is rated 600 volts so it can easily be used as part of a tuned filter. The proposed

filter design is illustrated in the one line diagram below. The following page gives the

specifications for the filter reactor that should be purchased.

480 Volt Bus

Tuned

Capacitor

Bank

Capacitor Bank:937.5 kvar

600 volts

Inductors:

0.046 mH per phase

rms current rating = 1100 amps

5th harmonic current rating =

775 amps

Circuit Breaker:480 Volt, 2000 A

Proposed Filter Configuration for Lines 13 and 14


17/19



Low Voltage Filter Calculations: 600 kvar 480 Volt Filter

SYSTEM INFORMATION:

Filter Specification: 5 th Power System Frequency: 60 Hz

Capacitor Bank Rating: 937.5 kVAr Capacitor Rating: 600 Volts

Rated Bank Current: 902 Amps 60 Hz

Nominal Bus Voltage: 480 Volts Derated Capacitor: 600 kVAr

Capacitor Current (actual): 721.7 Amps Total Harmonic Load: 2500 kVA

Filter Tuning Harmonic: 4.7 th Filter Tuning Frequency: 282 Hz

Cap Impedance (wye equivalent): 0.3840 Cap Value (wye equivalent): 6907.8 uF

Reactor Impedance: 0.0174 Reactor Rating: 0.0461 mH

Filter Full Load Current (actual): 755.9 Amps Supplied Compensation: 628 kVArFilter Full Load Current (rated): 944.9 Amps

Transformer Nameplate: 3750 kVA Utility Side Vh: 2.00 % THD

(Rating and Impedance) 7.00 % (Utility Harmonic Voltage Source)

Load Harmonic Current: 20.00 % Fund Load Harmonic Current: 601.4 Amps

Utility Harmonic Current: 175.5 Amps Max Total Harm. Current: 776.9 Amps

CAPACITOR DUTY CALCULATIONS:

Filter RMS Current: 1084.0 Amps Fundamental Cap Voltage: 502.8 Volts

Harmonic Cap Voltage: 103.3 Volts Maximum Peak Voltage: 606.1 Volts

RMS Capacitor Voltage: 513.3 Volts Maximum Peak Current: 1532.8 Amps

CAPACITOR LIMITS: (IEEE Std 18-1980) FILTER CONFIGURATION:

Limit Actual

Peak Voltage: 120 % 101%

Current: 180% 120%

KVAr: 135% 103%

RMS Voltage: 110% 86 %

FILTER REACTOR DESIGN SPECIFICATIONS:

Reactor Impedance: 0.0174 Reactor Rating: 0.0461 mH

Fundamental Current: 755.9 Amps Harmonic Current: 776.9 Amps

4 8 0 V o l t B u s

6 0 0 k V A r @

6 0 0 V o l t s

X l = 0 . 0 27 2


18/19



Appendix A: Low Voltage Power Factor Correction Equipment

Manufacturers

ABBSteve Colvin

1206 Hatton RoadWichita Falls, TX 76302

817-761-3232 / 817-761-3202

Aerovox Group

John Childs

740 Belleville Ave.

New Bedford, MA 02745-6194

508-994-9661 / 508-990-8696

ASC Industr ial

Bruce Marzley / Larry Burch / Chuck Gougler

8967 Pleasantwood Ave NW

North Canton, OH 44720216-499-1210 / 216-499-1213

Commonwealth Sprague

Frank Smith

Brown Street

North Adams, MA 01247

413-664-4466 / 413-664-4465

Control l ix

Paul Griesmer

21415 Alexander Road

Walton Hills, OH 44146

216-232-8757 / 216-232-1893

Freeborn IndustriesRudy Wodrich / Kevin Simpson

6675 Rexwood Road

Mississauga, Ontario

L4V 1V1 Canada

905-677-9272 / 905-677-5448

General ElectricPeter Baltz

14131 Midway Road, Suite 500

Dallas, TX 75244

214-702-5274 / 214-702-5283

Gilbert/K&M

Neal Ciurro / Jess Hancock

P.O. Box 1141

Beckly, WV 25802

304-252-6243 / 304-252-6292


19/19


Electrotek C t I 17

Macroamp LesatBob Stuefen / Allan Freebury

P.O. 1512

Ukiah, CA 95482

707-462-2222 / 707-462-3068

Myron ZuckerJim Holley315 East Parent Street

Royal Oak, MI 48067

810-543-2277 / 810-543-1529

RobiconDennis Lorenzi

100 Sagamore Hill Road

Pittsburgh, PA 15239-2982

412-325-7260 / 412-733-8093

TCI

J. P. Thorpe7878 North 86th St.

Milwaukee, WI 53224

414-357-4480 / 414-357-4480

Tech-Tran Corp

Ted Furst / Charles Roney

50 Indel Avenue

Rancocas, NJ 08703

800-257-9420 / 609-267-6751

VAR+ Controls

Bill McConnellMail Box 585

Whitmore Lake, MI 48189

800-KILOVAR / 313-449-8710

Versatex Indus tries

Ted Noutko

P.O. Box 354

Brighton, MI 48116

810-229-5751 / 810-229-7863

caso estudio armonicos y correccion fp - fabrica

Documents