icaaet-960

Proceedings of International Conference on Advances in Applied Engineering and Technology 2015, May 14-16, 2015.

Organized by Syed Ammal Engineering College, Ramanathapuram, Tamilnadu, India.

Power Quality Analysis and Recommendations Based on Real

Field Measurement Datas

1P.K.Mani,

2Dr.K.Siddappa Naidu,

1Associate Professor, Department of Electrical and Electronics Engineering, VEL TECH MULTITECH, Chennai-600062.

2Professor, School of Electrical and Electronics Engineering, VEL TECH UNIVERSITY, Avadi, Chennai-600062.

Abstract

In years past, most electrical equipment operated on an ideal

voltage and current waveform. However, in the past couple

of decades there has been an explosion in the use of solid-

state electronic technology. This new, highly efficient,

electronic technology provides improved product quality

with increased productivity by the use of smaller and lighter

electrical components. Today we are able to produce

products that cost less than in years past, but this new

technology requires clean electric power and is highly

sensitive to power distortions.

Electronic equipment (switching power supplies) draws

current differently than non-electronic equipment. Instead of

a load having a constant impedance drawing current in

proportion to the sinusoidal voltage, electronic devices

change their impedance by switching on and off near the

peak of the voltage waveform. Switching loads on and off

during part of the waveform results in short, abrupt, non-

sinusoidal current pulses during a controlled portion of the

incoming peak voltage waveform. These abrupt pulsating

current pulses introduce unanticipated reflective currents

(harmonics) back into the power distribution system. The

currents operate at frequencies other than the fundamental 50

Hz. Harmonic currents can be likened to the vibration of

water in a water line when a valve is open and closed

suddenly. In this paper power quality analysis done based on

the real field measurements in a spinning mill reported and

the recommendations are suggested.

Keywords: Power Quality, Harmonics, AHF, THD,

Nonlinear loads.

1. Introduction The actual problems of any Project will vary, depending on

the types and number of installed harmonic producing loads.

Most Projects can withstand nonlinear loads of up to 15% of

the total electrical system capacity without concern, but,

when the nonlinear loads exceed 15% some non-apparent

negative consequences can be expected. For Projects that

have nonlinear loading of more than 25%, particular

problems can be become apparent. The following is a short

summary of most, but not all of the problems caused by

harmonics:

Capacitor Failure - Harmonic Resonance

Circuit Breakers Tripping - Inductive Heating and

Overload

Computer Malfunction or Lockup - Voltage

Distortion

Conductor Failure - Inductive Heating

Electronic Equipment Shutting down - Voltage

Distortion

Flickering of Fluorescent Lights - Transformer

Ballast Saturation

Fuses Blowing for No Apparent Reason - Inductive

Heating and Overload

Motor Failures (overheating) - Voltage Drop

Neutral Conductor and Terminal Failures - Additive

Currents

Overheating of Metal Enclosures - Inductive

Heating

Power Interference on Voice Communication -

Harmonic Noise

Transformer Failures - Inductive Heating

The heating effects of harmonic currents can cause

destruction of equipment, conductors, and fires. The results

can be unpredictable legal and financial ramifications.

Voltage distortions can lead to overheating of equipment,

electronic equipment failure, expensive downtime, and

maintenance difficulties. Harmonic currents and voltage

distortion are becoming the most severe and complex

electrical challenge for the electrical industry. The problems

associated with nonlinear loads were once limited to isolated

devices and computer rooms, but now the problem can

appear throughout the power and utility system.

Our work consists of the following:

Power Quality Audit

Graphical analysis

Recommendations

Conclusion.

2. Scope of Work

A. OBJECTIVE:

To conduct Reactive Power Flow study and Power Quality

Audit and measure the level of Harmonics and the reactive

power requirement.

To suggest a suitable solution to improve the Power Factor at

the correct location and maintain the Power Quality in the

Network as per International norms.

B. INSTRUMENTS USED:

METREL Power Quality Analyser Plus which displays and

stores Active Power, Reactive Power, Apparent Power,

Power factor, Displacement power factor, Total harmonic

distortion of voltage and current each individual phase wise,

Oscilloscope waveform of voltage and voltage harmonics,

current and current harmonics, etc.



C. MEASUREMENT CONDITIONS:

Measurements were carried out in the following locations:

1. 33 KV HT TOTAL INCOMER

2. TRANSFORMER -1, 2MVA

a) F1 BLOW ROOM.

b) F2 SPINNING G 5/1 M/C's 5-8.

c) F3 PREPORATORY -1.

d) F4 HUMIDIFICATION PLANT 1.

e) F5 SPINNING G 5/1 M/C's 1-4.

f) F6 COLONY LIGHTNING.

g) F7 NEW PREPORATORY.

h) F8 SPINNING G 5/1 M/C's 22-25.

I) F9 SPINNING G 5/1 M/C's 9-12.

j) F10 COMBER PLANT.

k) F11 DOUBLING & SPINNING.

l) F12 SPINNING 6/S M/C's 17-20.


a) F13 SPINNING G 5/1 M/C's 17-21.

b) F14 SPINNING G 5/1 M/C's 13-16.

c) F15 HUMIDIFICATION PLANT 2 & LR 6/S Plant

1&2.

d) F16 PREPORATORY -2.

e) F17 SPINNING LRD J/5 1-10(Pump House).

f) F18 FACTORY LIGHTNING.

g) F19 SPINNING LR 6/S M/C's 9-13.

h) F20 CONE WINDING.

i) F21 ACW 338-1-7.

j) F22 SPINNING LR 6/S M/C's 14-17.

k) F23 SPINNING LR 6/S M/C's 1-4.


a) F45 RETIRE BLOW ROOM.

b) F46 RETIRE PREPORATORY -1.

c) F47 RETIRE PREPORATORY -2&3.

d) F48 SPINNING LR 6 25-27 & H.PLANT.

e) F49 K441 SPINNING 9-12.

f) F50 SPINNING LR 6 22-24 & H.PLANT.

g) F51 NEW AUTO CONE WINDING.

h) F52 K441 SPINNING 5-8.

i) F53 K441 SPINNING 1-4.

j) F54 AUTO CONOR H.PLANT & RETIRE

PREPORATORY.


a) F37 LIGHTNING RETIRE PROJECT.

b) F38 DJ/S SPINNING H.PLANT.

c) F39 SPINNING LR 60 A 11-13.

d) F40 SPARE.

e) F41 SPINNING LR 60 A 1- 5.

f) F42 SPINNING LR 60 A 6-10.

D. MEASUREMENT TECHNIQUES:

Using high speed Power Quality Analyzer, various

instantaneous Power Parameters are recorded for Analysis &

Evaluation of opt System. The Parameters logged includes

Phase Voltage, Line Currents, Power Factor, Active Power,

Reactive Power, Apparent Power, THD, Voltage Harmonics,

THD Current Harmonics and Individual Voltage & Current

Harmonics.

These Parameters are logged on Individual Phase and 3

Phase for proper analysis. The high speed analyzer measures

128 Samples per cycle (20 milli seconds) and variations are

recorded. The recording interval is selected as appropriate to

the study, depending on the Loading pattern. We are

summarizing the parameters recorded in Graphical Pattern

for relevant parameters.

E. DATA LOGGING

For the above objective, data logging of Power, Waveform,

Harmonic Parameters were carried out at the following

locations:

Measurements were carried out at Three Transformer nodes

i.e., LV side of 2500 KVA. These transformers were being

operated in parallel with LV side Bus couplers closed.

Studies were carried out at all Incomers and major Feeders

connected of Transformers.

F. DATA REPRESENATION

The following Graphical and Tabulation Forms of the

Readings recorded are annexed which indicates the data

logged:

Load Flow Tables.

Trend Graphs.

Harmonic Spectrum Current.

Waveforms of Current & Voltage.

G. PATTERN OF RECOMMENDATION

The recommendations are on the following Pattern, taking

into consideration the Mandatory IEC Guidelines &

Statutory IEEE Guidelines for Voltage & Current

Harmonics. The Recommendations are grouped as given

below:

Group I Level of Harmonics:

Where the levels of Harmonics are lesser than IEEE / IEC

Guidelines for Harmonics and Capacitors having specific

guaranteed Harmonic Withstand Capability are

recommended.



Group II Level of Harmonics:

Where the levels of Harmonics are higher than the IEEE /

IEC limits, recommendation is to provide Automatic

Switched Harmonic Filter System which will consist of

Capacitors & Reactors. These Automatic Operation of

Capacitors and Harmonic Filters improve the power factor

and also the Harmonic Filters suppress the Current

Harmonics. Hence, the Average P.F will be maintained for

the Loads with the suppression of Harmonics.

3. Overall View of the plant

4. Analysis of the readings at the 33kV HT indoor

breaker (SAMPLE CASE)

POWER PARAMETERS

The KVA and KW are the

normal running loads during

the Time of study 3456 KW

and 3524 KVA.

The load currents are normal

during the Time of study.

800 amps VCB has been

used.

0.00

0.03

0.06

0.08

0.11

0.14

0.16

0.19

0.21

0.24

0.27

0.29

0.32

0.35

0.37

0.40

0.43

0.45

0.48

0.50

0.53

09.02.2013. 14:42:00 09.02.2013. 14:47:45Relation 1 : 1

St+ (MVA) Av g Pt+ (MW) Av g Qti+ (MVAr) Av g

Periodic s (PAKSHALA.PMD)



POWER FACTOR

The Reactive Power varies

with the Active Power

variation.

The system with appx. - 687

KVAR capacitors are

connected Excess.

The Power Factor are found

at Leading 0.98C at the time

of study.

CURRENT

WAVEFORM

The variations in current

harmonic levels are

recorded.

It is indicated that the

Current Harmonic levels

disturb the current

waveform.

Unbalance Current flows in

each Phase.

CURRENT

The load currents are

normal running loads

during the Time of study.

An Trms Current of 63

Amps is measured.

The Reactive Power varies

with the Active Power

variation.

HARMONIC CURRENT

The variations in current

harmonic levels are

recorded.

The average Current

Harmonic Distortion levels

are measured as 12%


Current Harmonic levels are

HIGHER the limits of

standards for Harmonics.

VOLTAGE

WAVEFORM

The variations in Voltage

harmonic levels are

recorded.


Voltage Harmonic levels

disturb the Voltage

waveform.

Unbalance in Voltage is

found each Phase.

LOAD PARAMETER:

KW

KVA

KV

AR

PF

Volt

-

ag

e

Curr

-ent

TH

D

Volt

age

(%)

TH

D

Cur

rent

(%)

Freq

-uency

Neu

tral

Cur

rent

3456

3524 -687 0.98

C

21.1

KV

63A 2 12 49.88

Hz

3.9

RECOMMENDATION:

Present P.F is in the range of 0.98

Voltage harmonics recorded is approximately 2%, which is

LOWER than the IEEE 519 Guidelines for Harmonics.

Current harmonics recorded is approximately 12%, which is

also MARGINALLY HIGHER than the IEEE 519 Guidelines

for Harmonics.

As per IEEE guidelines reading shows it is maintaining at

LEADING Power Factor and the level of Current Harmonic

is higher. As we having KVAH billing it is necessary to

maintain unity PF at all time. So it is required to install ASHF

at the Incomer of all Transformer secondary side.

5. Some sample cases of load parameter and

recommendations

A. F- 4, HUMIDIFICATION PLANT 1:

LOAD PARAMETER:

K

W

KV

A

K

V

A

R

PF

Volt

-age

Cu

rr

-

ent

TH

D

Vo

lta

ge

(%

)

T

H

D

Cu

rre

nt

(%

)

Freq

-

uency

Ne

utr

al

Cu

rre

nt

36 60 48 0.60 247 85 6.2 20 50.04 3

0.88

0.89

0.90

0.91

0.92

0.93

0.95

0.96

0.97

0.98

0.99

1.00

1.01

1.02

1.03

1.05

1.06

1.07

1.08

1.09

1.10

09.02.2013. 14:42:00 09.02.2013. 14:47:45Relation 1 : 1

Pftc + Av g Pfti+ Av g


05.0

10.015.020.025.030.035.040.045.050.055.060.065.070.075.080.085.090.095.0

100.0t r igg t im e: 25. 12. 10. 12: 06: 28. 25

%

X ax is range: 1280 point strigg - 6399 points trigg - 5120 points

12.55

12.60

12.65

12.70

12.75

12.80

12.85

12.91

12.96

13.01

13.06

13.11

13.16

13.22

13.27

13.32

13.37

13.42

13.47

13.52

13.58

09.02.2013. 14:42:00 09.02.2013. 14:47:45Relation 1 : 1

I1 (A) Av g I2 (A) Av g I3 (A) Av g


0

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

45.00

50.00

55.00

60.00

65.00

70.00

75.00

80.00

85.00

90.00

95.00

100.00

09.02.2013. 14:42:00 09.02.2013. 14:47:45Relation 1 : 1

thdI1 (%) Max thdI2 (%) Max thdI3 (%) Max

Periodic s (PAKSHALA.PMD) in %

05.0

10.015.020.025.030.035.040.045.050.055.060.065.070.075.080.085.090.095.0

100.0t r igg t im e: 25. 12. 10. 12: 06: 28. 25

%

X ax is range: 1280 point strigg - 6399 points trigg - 5120 points



RECOMMENDATION:

Present P.F is in the range of 0.6 lagging.

Voltage harmonics recorded is approximately 6.2%, which is

very much HIGHER than the IEEE 519 Guidelines for

Harmonics. Current harmonics recorded is approximately

20%, which is very much HIGHER than the IEEE 519

Guidelines for Harmonics. Neutral Current of 3 Amps has

been found flowing through Neutral.

As per IEEE guidelines plant should be maintaining at Unity

Power Factor. So it Necessary to add 60 KVAR Fixed Tuned

Filter to increase PF and Harmonic Amplification.

A. F2- SPINNING G 5/1 M/Cs 5-8:

LOAD PARAMETER:

K

W

KVA

KV

A

R

PF

Vo

lt

-

ag

e

Curr

-ent

T

H

D

Vo

lta

ge

(%

)

TH

D

Curr

ent

(%)

Freq

-

uenc

y

Ne

utr

al

Cu

rre

nt

8

0

108 72 0.7

4

24

3V

158

A

5 15 49.9

5Hz

0

RECOMMENDATION:

Present P.F is in the range of 0.74 LAGGING

Voltage harmonics recorded is approximately 5%, which is

very much MARGINALLY HIGHER than the limit IEEE

519 Guidelines for Harmonics. Current harmonics recorded

is approximately 15%, which is very much HIGHER than the

limit of IEEE 519 Guidelines for Harmonics. Neutral Current

of 0 Amps has been found flowing through Neutral.

As per IEEE guidelines plant should be maintaining at

LEADING Power Factor, while capacitor are in ON

condition. So it Necessary to add 100 KVAR Auto Switched

Harmonic Filter panel in this DB.

6. Things to be done for better power quality and

savings in the plant

1. AUTO SWITCHED HARMONIC FILTERS TO BE

INSTALLED AT ALL THE INCOMERS.

2. RING FRAME WITH INVERTER DRIVES SHOULD

BE PROTECTED WITH LINE.

3. BASED ON THE RECOMMENDATION, PASSIVE

FILTERS SHOULD BE INSTALLED AT LOAD END.

4. AFTER INSTALLING PASSIVE FILTERS,

FURTHER FOR FINE TUNING PURPOSE, ACTIVE

FILTERS SHOULD BE INSTALLED.

7. Conclusion

System has Higher Current Harmonic of 12% in 33KV, HT side.

Due to the transportation of low linear path, Effect of Harmonic is more in linear load.

By installing Filter in the Load end, improves the Lower PF and reduces cable losses. Our recommendation will help

to increase the PF, decrease the cable losses and some

percentage of Harmonic will be get filtered in load end itself.

B phase Voltage and Current recorded as Higher and phase unbalance is also found.

Excess Neutral Current is measured at the Incomer. Once three phase voltage and Current made balance, it will

get reduced.

Failure rate Electrical system will be reduced by installing tuned filters at the load end and default saving will

be achieved as per the recommendation.

REFERENCES

[1] Mauricio Aredes, Klemens Heumann, Edson H.

Watanabe, An Universal Active Power Line Conditioner,

IEEE Transactions on Power Delivery, Vol. 13, No. 2, April

1998.

[2] B. Singh, and K. Al-Haddad, A review of active filters

for power quality improvement,IEEE Transactions on

Industrial Electronics, vol. 46, no. 5, pp. 960-971, Oct. 1999.

[3] Charles. S, and G. Bhuvaneswari, Comparison of three

phase shunt active power filter algorithms, International

Journal of Computer and Electrical Engineering, vol. 2, no.

1, pp. 175- 180, Feb. 2010.

[4] S. P. Litran, P. Salmeron, J. R. Vazquez, and J. L.

Flores, Compensation of voltage unbalance and current

harmonics with a series active power filter, Renewable

Energy & Power Quality Journal, no. 3, Mar. 2005.

[5] L. Chen, and A. V. Jouanne, A comparison and

assessment of hybrid filter topologies and control

algorithms, IEEE/PESC Ann. Meeting Conf, vol. 2, pp. 565-

570.

[8] E. R. Ribeiro, and I. Barbi, Harmonic voltage

reduction using a series active filter under different load

conditions, IEEE Transactions on Power Electronics,

vol. 21, no. 5, pp. 1394-1402, Sep. 2006.

[9] KannanKarthik, and J.E.Quaicoe, Voltage

Compensation and harmonic suppression using series active

and shunt passive filters,Electrical and Computer

Engineering, Canadian conference, vol. 1, 2000, p. 582-586.



[10] H. Fujita, and H. Akagi, A practical approach

to harmonics compensation in power systems series

connection of passive and active filters,IEEE Transactions

on Industry Applications, vol. 27, no. 6, pp.1020-1025,

Nov. 1991.

[11] J.C.Das,"Power System Harmonics and

Passive Filter Designs" IEEE Press Series on Power

Engineering Series: Wiley; 2015

About the authors

P.K.Mani has completed his B.E.

Electrical and Electronics Engineering

and M.E. Power Systems Engineering at

Anna University, Chennai. At present he

is working as Associate Professor in

Electrical and Electronics Engineering

Dept, Vel Tech Multitech Dr.Rangarajan

Dr.SakunthalaEngineering college, Chennai-

600062.Currently he is doing Ph.D in Veltech

Dr.RR&Dr.SRTechnical University in the field of power

quality. Mobile. No: +91 9445260989.

Email: [email protected].

Dr.K.Siddappa Naidu finished his

B.E.Electrical Engineering from Sri

Venkateswara University, Tirupati in 1973

and got post-graduation from IISC,

Bangalore in 1976 and Ph.D. from the same

institute in 1994. He has worked in various

capacities in NGEF Transformers Research

& Development from 1979 to 2000.He

worked as HOD EEE, Vice Principal and Principal in different

Engineering colleges from 2000 to 2012.Presently working as

Dean, School of Electrical Engineering in Vel Tech Dr.RR

Dr.SR Technical University, Avadi, Chennai-600062.He has

published many papers in international and national journals.

His research interests are partial discharge measurements in

HV Insulation & Apparatus, online monitoring of HV power

apparatus, Sub synchronous, Renewable energy systems and

power quality.

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