Volume 4, Issue 7, July – 2019 International Journal of Innovative Science and Research Technology

ISSN No:-2456-2165

Study and Solution of Reactive Power Compensation,

Harmonics Mitigation and Load Balancing for Power
Factor improvement of Jaipur Metro Power Supply
System using Active Harmonic Filters
Bharat Lal Mali Dr. Pramod Sharma
M. Tech. Scholar, Professor,
Regional College for Education Research and Technology Regional College for Education Research and Technology
Sitapura, Jaipur Sitapura, Jaipur

Abstract:- This paper presents a study and solution of improve the true power factor is our main concern. The PF
different power quality issues of Jaipur Metro Rail is given as:
Corporation (JMRC) power supply system. The
measurement of different parameters was taken at KW
132kv incoming feeder of Jaipur Metro Receiving Sub PowerFactor 
Station. The measured data were analyzed and different KVA (1)
power quality issues like excess reactive power; current
harmonics and load unbalancing were observed. These B. Displacement Power Factor (Cos  ):
power quality issues makes power factor poor. A The Displacement power factor is the Cosine of angle
solution of these power quality issues using Active between fundamental voltage and fundamental current
Harmonics Filter has been proposed. waveforms. Thus simply the Displacement Power Factor is
Cos  of fundamental wave. Thus Displacement Power
Keywords:- Power Quality, Harmonics, Load unbalancing, Factor is remains unaffected from voltage and current
Reactive Power, Power Factor, Active Harmonics filter, harmonics and is always greater than or equal to true Power
Non Linear Loads, Total harmonics Distortion (THD). factor.
I. INTRODUCTION C. Distortion Power Factor (DPF):
The distortion power factor term is introduced by the
The Metro Railway network is increasing rapidly in harmonics. The distortion power factor is given by:
India. The Metro Railways power supply system consist
large cabling network which causes problem of excess
1
reactive power. The metro railway loads are nonlinear and DPF  (2)
unbalanced due to single phase traction load which causes (1  iTHD 2 )
generation of harmonics and load unbalancing. Thus metro
railways power supply system suffers with power quality
The True Power factor in terms of Displacement
issues like excess reactive power flow, harmonics and load
Power factor and Distortion Power factor is given by:
unbalancing etc. These power quality issues makes power
factor poor.
PF (True)  Cos  DPF (3)
II. POWER FACTOR
The factors affecting the power factor are as under:
Power Factor is the ratio of Useful Power (kW) to
Apparent Power (kVA). The value of PF should be  Reactive Power
maintained at unity for reduced losses and optimum  Harmonics
capacity utilization. The power Factors further can be  Load Unbalance
classified as under [1], [2]:
 Reactive Power
A. True Power Factor (PF) The relation of Active Power, Reactive Power and
The True Power factor is the ratio of Active Power to Apparent Power can be understood by Power triangle given
the Apparent Power which is containing effect of voltage below:
and current harmonics and load unbalance also. The
presence of Voltage and Current harmonics makes the true
power factor poor and is always less than Displacement
Power Factor (Cos  ). The power supply utilities apply PF
penalties/rebates on true power factor. Therefore to

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Volume 4, Issue 7, July – 2019 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165
III. SOLUTION OF POWER FACTOR
IMPROVEMENT

The power factor of any system having power quality

issues like reactive power flow, Harmonics distortion, load
unbalancing and neutral current can be improved by Active
power filter only. The Active Power filter is capable to fix
all kind of power quality issues as discussed above.

A. Active Power Filter

The Active Power Filter’s (APF) are voltage source
converter based device which do not uses any passive
elements for generation of reactive power. The Shunt APF
is used for the harmonic currents, load balancing and
reactive power compensation. Shunt APF consists of a
Fig 1:- Power Triangle three phase VSI with a capacitor which acts as a voltage
controlled current source [7], [8].
From the Power triangle, the Apparent Power is given
by: IV. JMRC SUPPLY SYSTEM

2 JMRC receives power supply at 132KV at its

 P Q
2 2
S Receiving Sub Station (RSS). JMRC have two RSS namely
(4) Mansarovar (MSOR) and Sindhicamp (SICP). 132KV
supply is step down to 33KV, 3-Phase to feed auxiliary
Thus from equation (1) and (4) it can be concluded load of all metro stations and 25KV single phase to feed
that Power factor is further depend on flow of Reactive traction load for train operation. An overview of complete
Power. If the generation Reactive Power is equal to JMRC supply system has shown in fig. 2.
consumption of Reactive Power i.e. there is no reactive
power flow in the network, then the system Power Factor
will be unity.

 Harmonics
Harmonics are sinusoidal voltages or currents having
frequencies that are multiples of the fundamental frequency
at which the supply system is designed to operate. The
harmonic currents generated by the load or more accurately
converted by the load from fundamental to harmonic
current have to flow around the circuit via the source
impedance and all other parallel paths. As a result, Fig 2:- JMRC Supply System Overview
harmonic voltages appear across the supply impedance and
are present throughout the installation [3], [4]. V. MEASUREMENTS

 Load Unbalancing The measurement of different parameters was taken

Unbalance in a 3 Phase system is marked by a using power quality analyzer at 132KV incomers of both
difference in the magnitude of current/voltage in different RSS of JMRC. The graphs of measured parameters have
phases or when the phase separation is not 120 degrees. A given in fig. 3, 4, 5, 6 respectively.
balanced three-phase AC system acts like three independent
single-phase systems. There’s no neutral current, and the
total active and reactive powers are just the arithmetic sum
of the active and reactive phase powers. When there is any
phase unbalance or harmonics, this classical (arithmetic)
approach doesn’t hold for apparent power. We need either
IEEE 1459 or the Unified Power Measurement (UPM)
method to calculate it. If the real power differs substantially
from apparent power, the true power factor gets poor [5],
[6].

Fig 3:- Measurement of Power

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Volume 4, Issue 7, July – 2019 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165

S.N. Parameter MSOR SICP

1 Active Power (MW) 3 2
2 Reactive Power (MVAR) -2.7 -1.7

3 Apparent Power (MVA) 4.5 3

3 Power Factor 0.33 0.4

4 Cosϕ 0.37 0.45

5 iTHD (%) 10 12
Fig 4:- Measurement of PF & DPF
6 Load Unbalance (%) 14 10
Table 1:- Measurement Summary

B. AHF Rating calculation

Based on the measurement summary, the AHF rating
for mitigation of different power quality issues can be
calculated as:

 For Reactive Power Compensation

The AHF current rating for Reactive Power
compensation can be calculated as under:

Reactive Power (Q)

A (AHF)  (3)
 3  AHF Voltage
Fig 5:- Measurement of Harmonics
Where Q is the required reactive power to be
compensated and V is AHF voltage.

 For Harmonics Mitigation

Thus AHF current rating for harmonics mitigation at
415 voltages can be calculated as:

Current  THDi  Voltage

A(AHF)  (4)
AHF Voltage 100

 For Load Balancing

I(-)  Voltage
A (AHF) 
AHF Voltage (5)
Fig 6:- Measurement of I (-) Based on the calculation of AHF ratings (A) as per
equations (3), (4) and (5), the ratings of AHF have given in
A. Measurement Summary table 2.
Based on the measurement of Power, Power Factor,
Harmonics and load unbalancing as shown in fig. 3, 4, 5
and 6 the measurement summary of different parameters For For I
S.N. RSS For Q Total
has shown in below table: iTHD (-)

1 MSOR 4174 890 4451 9515

2 SICP 2782 762 3186 6731

3 Both 6956 1653 7637 16246

Table 2:- AHF Rating

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Volume 4, Issue 7, July – 2019 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165
C. Proposed Scheme
Based on the AHF rating calculation, the proposed scheme of power factor improvement with location of Active Harmonic
filter (AHF) has shown in fig. 7.

Fig 7:- Proposed Scheme

VI. CONCLUSION Improvement in a Nonlinear Loaded Electrical

Installation,” RE&PQJ, Vol. 1, No.1, April 2003.
From the study of a typical metro supply system for [4]. Sourabh Gupta, Preeti Gupta, “Harmonics Mitigation
power quality improvement by Active Power Filter, the Using Active Power Filter,” International Journal of
following conclusions are drawn:- Advanced Computer Research (ISSN (print):2249-
7277 ISSN (online):2277-7970) Volume-3 Number-2
 Most of the loads connected to the system are non- Issue-10 June-2013.
linear which generates harmonics in the system. [5]. Zakir Husain, Ravinder Kumar Singh and Shri Niwas
 The single phase traction load causes load unbalancing. Tiwari, “Balancing of Unbalanced Load and Power
 The use of cabling network causes generation of excess Factor Correction in Multi-phase (4-phase) Load
reactive power which causes power factor poor Circuits using DSTATCOM,” Proceedings of the
(leading). World Congress on Engineering 2010 Vol II.WCE
 The JMRC load is dynamic in nature due to traction 2010, June 30 - July 2, 2010, London, U.K.
load. Therefore only dynamic compensation i.e. Active [6]. DENISA RUSINARU, LEONARDO-GEO
Power Filter can be used for Power Factor MANESCU, MARIUS MERFU, “The Load
Improvement. Unbalance Influence on the Power Factor Value in
 Therefore to mitigate these all power quality issues Three-Phase Distribution Networks,” Recent
which are causing power factor poor, Active Power Researches in Electric Power and Energy Systems
Filter has been proposed at load level at 415V. ISBN: 978-960-474-328-5.
[7]. Randeep Singh Chib, Mehak Sharma, Hartaj Singh,
REFERENCES “Active filter and reactive compensation using
DSTATCOM” Randeep et al, Journal of Engineering
[1]. P. Salmerón, J. R. Vázquez, R. S. Herrera and S. P. Research and Studies E-ISSN0976-7916, J Engg Res
Litrán, “Apparent power and power factor in Studies /IV/IV/Oct.-Dec., 2013/10-15.
unbalanced and distorted systems. Applications in [8]. Arun Shankar V.K., Senthil Kumar N.,
three phase load compensations” RE&PQJ, Vol. 1, “Implementation of Shunt Active Filter for Harmonic
No.5, March 2007. Compensation in a 3 Phase 3 Wire Distribution
[2]. Pragya Patel, Dharmendra Kumar Singh, “Evaluating Network,” 1st International Conference on Power
Power Factor and Thd of Power Supply using Various Engineering, Computing and CONtrol, PECCON-
Correction Circuits and Filters,” International Journal 2017, 2-4 March 2017, VIT University, Chennai
of Engineering Research & Technology (IJERT) Campus.
ISSN: 2278-0181Vol. 3 Issue 12, December-2014.
[3]. António P. Martins, “The Use of an Active Power
Filter for Harmonic Elimination and Power Quality

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