This document is a project report submitted by four students for their Bachelor of Engineering degree. The project investigates the optimal location of Interline Power Flow Controllers (IPFC) in power transmission systems. The objectives are to maintain voltage profiles and real and reactive power flows. The scope involves improving voltage profiles and power transfer capabilities using IPFCs. Recently, FACTS devices like IPFCs have attracted interest for applications like congestion management and cost reduction. The problem is that few publications have investigated IPFC locations in power systems and their effects. The report is organized into chapters covering theory, location determination methods, IPFC performance simulation and results.

1. OPTIMAL LOCATION OF INTERLINE POWER
FLOW CONTROLLER (IPFC) IN POWER
TRANSMISSION SYSTEM
A PROJECT REPORT
Submitted by
PRAKASH CHANDRA 3460810232
PRABHAT CHANDR 3460810230
PRANAV KUMAR 3460810235
RAHUL KUMAR 3460810243
in partial fulfillment for the award of the degree
of
BACHELOR OF ENGINEERING
IN
ELECTRICALAND ELECTRONICS ENGINEERING
AARUPADAI VEEDU INSTITUTE OF TECHNOLOGY,
PAIYANOOR
VINAYAKA MISSIONS UNIVERSITY, SALEM
APRIL 2012

2. VINAYAKA MISSIONS UNIVERSITY
AARUPADAI VEEDU INSTITUE OF TECHNOLOGY
BONAFIDE CERTIFICATE
Certified that this Project Report “OPTIMAL LOCATION OF INTERLINE
POWER FLOW CONTROLLER(IPFC) IN POWER TRANSMISSION
SYSTEM ” is the bonafide work of “Prakash chandra (3460810232), Prabhat
chandr (3460810230), Pranav kumar (3460810235) & Rahul kumar
(3460810243)” who carried out the project work under my supervision.
SIGNATURE SIGNATURE
Dr. N. VEERAPPAN, M.E., Ph.D Ms. G.NITHYA,BE, M.E.
HEAD OF THE DEPARTMENT SUPERVISOR
Lec / EEE
Department of EEE Department of EEE
AVIT, Paiyanoor AVIT, Paiyanoor
Chennai – 603104 Chennai - 603104
Project viva voce held on _____________________
INTERNAL EXAMINER EXTERNAL EXAMINER

3. ACKNOWLEDGEMENT
We, the project members firstly thank The Almighty for the divine intervention,
guidance and the blessings bestowed upon us throughout the tenure of our project
work.
We are also very grateful to Dr. A.S. Ganesan, Vice Chairman,
Vinayaka Missions Research Foundation and Dr. N.R. Alamelu, M.E., PhD,
Principal, AVIT, Paiyanoor for providing us the adequate support and facilities in
the college for completing this Project Work.
We would like to express our sincere gratitude to our HOD(EEE), Dr.
N. Veerappan, M.E., PhD, for granting us his kind permission to realize this
Project and also for his proper guidance, valuable advice, support and
encouragement.
We extend our thanks to our guide MS. G.NITHYA, BE, ME / EEE, for guiding to
complete this project successfully.
We are grateful to our Project Co-ordinators, Mrs.B.Sowmya, Asst Prof (Gr-II) &
Mrs. J.Suganthi, Asst Prof, EEE Department for guiding us in realizing our
project successfully.
Our sincere thanks are also to the other faculty members and non-teaching staff of
EEE Department for their kind co-operation for the successful completion of this
project.
Last but not the least, we extend our thanks to our parents, family members and
friends for their prayers and encouragement for completing this project
successfully.
PRAKASH CHANDRA
PRABHAT
CJANDR PRANAV
KUMAR
RAHUL KUMAR

6. CHAPTER 1
INTRODUCTION
1.1 Background
Flexible AC Transmission System (FACTS) was first introduced by Narain
G. Hingorani in the United States of America in the year of 1988. The FACTS
controller is defined by the Institution of Electrical and Electronics Engineers
(IEEE) as “a power electronic based system and other static equipment that
provide control of one or more AC transmission system parameters to enhance
controllability and increase power transfer capability”. There are 3 main categories
in FACTS Controller, which are namely series, shunt, shunt-series or series-series
FACTS Controller with every categories have its own functions.
The series connected FACTS Controller uses the basic principle of the cancellation
of a portion of the reactive line impedance could increase the transmittable power.
This is due to the fact that AC power transmission over long lines was primarily
limited by the series reactive impedance of the line. The series connected FACTS
Controller could improve the voltage stability limit, increase the transient stability
margin, power oscillation damping and sub-synchronous oscillation damping.
Some examples of the series FACTS Controllers are Thyristor2 Switched Series
Capacitor (TSSC), Thyristor-Controlled Series Capacitor (TCSC) and Static
Synchronous Series Compensator (SSSC).
1

7. On the other hand, the shunt connected FACTS Controller uses the basic principle
of the steady state transmittable power and the voltage profile along the line could
be controlled by appropriate reactive shunt compensation. The shunt connected
FACTS Controllers could be used to improve the voltage profile of a specific bus,
improve the transient stability and power oscillation damping. Some examples of
then shunt connected FACTS Controllers are Static VAR Compensator (SVC) and
the Static Synchronous Compensator (StatCom).
For the combinational shunt-series and series-series connected FACTS Controllers
combines the main principles of the series and shunt connected FACTS
Controllers. It able to control, simultaneously or selectively, all the parameters
affecting the power flow in the transmission line, that are impedance, voltage and
the phase angle. The shunt series connected FACTS Controller provides
multifunctional flexibility required to solve many of the problems facing by the
power delivery industry. Some examples of shunt-series connected FACTS
Controllers are Unified Power Flow Controller (UPFC) and series-series FACTS
controller are Interline Power Flow Controller (IPFC).
1.2 Objectives of Project
Main objective of this project is to investigate the location and optimal
placement of interline power flow controller to maintain the voltage profile, real
and reactive power flow in transmission line in power system.
2

8. 1.3 Scope of Project
There are several scope that have been outlined in order to narrow and
specific the project in such a way that the objectives of the project could be
achieved. This project is to consider the ability to improve the voltage profile and
power transfer capability. Recently, Because of the problems such as the
congestion management, the reduction of the operational cost and the overall
generating cost, the additional control freedoms of FACTS devices have aroused
great interest in the application of FACTS devices especially the IPFC and the
Generalized Unified Power Flow Controller (GUPFC). The software that would be
used throughout the project is MATLAB based sim Power System.
1.4 Problem Statement
Recently, Because of the problems such as the Congestion management,
the reduction of the operational Cost and the overall generating cost, the additional
control freedoms of FACTS devices have aroused great interest in the application
of FACTS devices especially the interline power flow controller (IPFC) .
However, very few publications have been presented on the investigation on the
location of IPFC in power system and its effect. So, the study on optimal
placement and location investigation is described in this project.
1.5 Outline of project report
This report consists of 6 Chapters. The first chapter contained 5 sections,
namely Background, Objective of Project, Scope of Project, Problem Statement
and the Outline of the project report.
3

9. In the second chapter, Introduction of General Theory on FACTS Controllers,
Continuous Power Flow and reviews of related work are presented.
Chapter 3 elaborates on the determination of location of interline power flow
Controllers (IPFC).
Chapter 4 Interline power flow controller and its performance in power
transmission system.
Chapter 5 presents the results of simulation using MATLAB sim power software.
The chapter consists of simulation of test system with and without IPFC controller
and comparison of result for optimal placement of IPFC in test bus system.
Lastly, Chapter 6 concludes the thesis and presents several suggestions for future
work related to the project.
4

10. CHAPTER 2
THEORY AND LITERATURE REVIEW
2.1 Introduction
In this chapter, the basic working principle of the FACTS Controllers would
be discussed. It would also include brief overview of the continuous power flow
analysis. Lastly, the reviews of related work would also be included.
2.2 General Theory on FACTS Controllers
In general, FACTS Controllers can be divided into four categories:
• Series Controllers
• Shunt Controllers
• Combined series-series Controllers
• Combined series-shunt Controllers
Series Controllers: [Figure 2.2(b)] The series Controller could be a variable
impedance, such as capacitor, reactor, etc., or a power electronics based variable
source of main frequency, subsynchronous and harmonic frequencies (or a
combination) to serve the desired need. In principle, all series Controllers inject
voltage in series with the line. Even a variable impedance multiplied by the current
flow through it, represents an injected series voltage in the line. As long as the
voltage is in phase quadrature with the line current, the series Controller only
supplies or consumes variable reactive power. Any other phase relationship will
involve handling of real power as well.
5

11. Shunt Controllers: [Figure 2.2(c)] As in the case of series Controllers, the shunt
Controllers may be variable impedance, variable source, or a combination of these.
In principle, all shunt Controllers inject current into the system at the point of
connection. Even a variable shunt impedance connected to the line voltage causes a
variable current flow and hence represents injection of current into the line. As
long as the injected current is in phase quadrature with the line voltage, the shunt
Controller only supplies or consumes variable reactive power. Any other phase
relationship will involve handling of real power as well.
Combined series-series Controllers: [Figure 2.2(d)] This could be a combination
of separate series controllers, which are controlled in a coordinated manner, in a
multiline transmission system. Or it could be a unified Controller, Figure 1.4(d), in
which series Controllers provide independent series reactive compensation for each
line but also transfer real power among the lines via the power link. The real power
transfer capability of the unified series-series Controller, referred to as Interline
Power Flow Controller, makes it possible to balance both the real and reactive
power flow in the lines and thereby maximize the utilization of the transmission
system. Note that the term "unified" here means that the de terminals of all
Controller converters are all connected together for real power transfer.
Combined series-shunt Controllers: [Figures 2.2(e) and 2.2(f)] This could be a
combination of separate shunt and series Controllers, which are controlled in a
coordinated manner [Figure 2.2(e)], or a Unified Power Flow Controller with
series and shunt elements [Figure 2.2(f)]. In principle, combined shunt and series
Controllers inject current into the system with the shunt part of the Controller and
voltage in series in the line with the series part of the Controller. However, when
6

12. the shunt and series Controllers are unified, there can be a real power exchange
between the series and shunt Controllers via the power link.
7

13. Figure 2.2 Basic types of FACTS Controllers:
(a) general symbol for FACTS Controller; (b) series Controller; (c) shunt
Controller; (d) unified series-series Controller; (e) coordinated series and shunt
Controller; (f) unified series-shunt Controller; (g) unified Controller for multiple
lines; (h) series Controller with storage; (i) shunt Controller with storage;
(G) unified series-shunt Controller with storage.
8

14. 2.3 Continuous Power Flow
Basic principles of power flow control
To facilitate the understanding of the basic principle of power flow control and to
introduce the basic ideas behind the different type of FACTS controllers, the
simple model shown in Fig. 2. The sending and receiving end voltages are assumed
to be fixed. The sending and receiving ends are connected by an equivalent
reactance, assuming that the resistance of high voltage transmission lines is very
small. The receiving end is modeled as an infinite bus with a fix angle of zero
degree. .
Fig. 2.3(a) Model for calculation of real and reactive power flow control
9

15. 10

16. Fig. 2.3(b) Power angle curve
Complex, active and reactive power flows in this transmission system are defined,
respectively, as follows:
Similarly, for the sending end:
11

17. Where V S and V R are the magnitudes of sending and receiving end voltages,
respectively, while δ is the phase-shift between sending and receiving end voltages.
Fig2.3 shows the evolution of the active power delivered. It’s clear from the
demonstrated equations, that the active and reactive power in a transmission line
depend on the voltage magnitudes and phase angles at the sending and receiving
ends as well as line impedance.
2.4 Reviews of Related Work
The paper by S.Gerbex,R.Cherkaoui and A.J.Germond, Member ,IEEE. is mainly
about the optimal location of FACTS devices like TCSC, TCVR, TCPST, SVC and
UPFC. A.Dehghanpour, S.M.H.Hosseini and N.talebi , IEEE-2011 is mainly
worked on power flow management by IPFC in transmission system.
M.F.Moghadam, M.Khederzadeh, IEEE-2011. is mainly about voltage
compensation with IPFC using all degree of freedom.
Mahdad et. al. (2006) basically presented method on how to choose the type
of FACTS Controllers, the location (or the placement) and control the FACTS
12

18. Controllers. They use 2 types of compensation, namely the SVC for shunt
connected FACTS Controller and TCSC for series connected FACTS Controller.
They have stated that they would use system loading ability and loss minimization
as a measure of power system performance. Similar with the preceding paper, they
applied the continuous power flow method in order to determine the weak bus by
comparing the voltage profiles of each bus in the system. With the data obtained,
they have chosen the bus in which has the worst voltage profile (worst voltage
collapse among other buses). Based on their finding, they placed SVC and again,
they applied continuous power flow method to obtain the voltage profiles. After
comparison made the maximum loading parameter and the voltage stability proven
to be increased. For this project, the approach proposed by Mahdad et. al. (2006)
would be used to compare the FACTS Controllers. The use of CPF is more reliable
than the ordinary power flow method available for this case, since the power flow
method simulate the increasing of load, and therefore the FACTS Controllers
effects and performance are most likely could be studied.
CHAPTER 3
METHODOLOGY
3.1 Introduction
This project would demonstrate the effects and the performance of implementing
IPFC in the power system. Before the performance and the effect of IPFC in power
13

19. system were evaluated, firstly the location or the placement of the IPFC it selves
was determined. In realizing this, an analysis named continuous power flow
analysis was used in order to determine the weak bus and the underutilized line,
and hence determine the location of FACTS Controllers in the test system.
3.2 The Determination of Location of IPFC
The IPFC were placed on the location in such a way that the capability of
Controllers to compensate a particular bus or line could be optimized. Therefore,
continuous power flow analysis was applied in order to determine the weakest bus
and the underutilized line in the test system. The test system was analyzed with and
without the IPFC. Voltage profiles for all the buses in the test network were noted
and the bus in which collapses the worst among other buses has been selected as
the weak bus. On the other hand, based on the continuous power flow report, the
most underutilized line was determined. And finally the optimal location of
interline power flow controller is determined.
.
3.3 Summarized Flow Chart
The methodology adopted above is best explained by means of a flow chart.
Figure below shows the summarized the flow chart of the adopted methodology.
14

20. Figure 3.3(a) The flow chart of methodology adopted
15

21. The first thing is the selected test system, Test System is constructed by using the
MATLAB Simulink. Then, the CPF was applied on the test system without the
consideration of IPFC(base case) to obtain the performance of the system without
any compensation, and tabulate the CPF result. Then the implementation of IPFC
in the test system at different bus and find the voltage profile of each bus and also
the CPF report. Compare the tabulated results which is obtained from with and
without IPFC in test system at different location in the line. And finally find the
optimal placement of interline power flow controller in test system.
16

22. CHAPTER 4
OPERATION OF IPFC
4.1 INTRODUCTION
The ongoing expansion and growth of the electric utility industry
continuously introduce changes to a once predictable business. Electricity is
increasingly being considered and handled as a commodity. Thus transmission
systems are being pushed closer to their stability and thermal limits with the
focus on the quality of power delivered. In the evolving utility environment,
financial and market forces will continue to demand a more optimal and
profitable operation of the power system with respect to generation, transmission
and distribution. Advanced technologies are paramount for the reliable and
secure operation of power systems. To achieve both operational reliability and
financial profitability it is clear that more efficient utilization and control of the
existing transmission system infrastructure is required. Improved utilization of
the existing power system is provided through the application of advanced
control technologies. Power electronics based equipment or Flexible AC
Transmission systems (FACTS) provide proven technical solutions to address
these new operating challenges being presented today. FACTS technologies
allow for improved transmission system operation with minimal infrastructure
investment, environmental impact and implementation time compared to the
construction of new transmission lines. FACTS technologies provide advanced
solutions as cost effective alternative to new transmission line construction.
FACTS provide the needed corrections of transmission functions in order to
efficiently utilize existing transmission systems and therefore, minimize the gap
between the stability and the thermal level.
17

23. 4.2 INTERLINE POWER FLOW CONTROLLER (IPFC)
Objective of Interline Power Flow Controller (IPFC) is to provide a
comprehensive power flow control scheme for a multi-line transmission system, in
which two or more lines employ a SSSC for series compensation. A multi-line
IPFC comprises of number of ‘n’ SSSC’s, one for each line of the transmission
system to be controlled, with a common dc bus as illustrated schematically by a
block diagram as shown in Fig:4.1. The IPFC scheme has the capability to transfer
real power between the compensated lines in addition to executing the independent
and controllable reactive power compensation of each line. This capability makes it
possible to equalize both real and reactive power flow between the lines, to transfer
power demand from overloaded to under-loaded lines to compensate against
resistive line voltage drops and the corresponding reactive line power and to
increase the effectiveness of the compensating system for dynamic disturbance like
transient stability and power oscillation.
Fig: 4.2(a) General schematic of IPFC
Consider a IPFC scheme shown in Fig:4.2 consisting of two back-to-back dc to ac
inverter each compensating a transmission line by series voltage injection. This
arrangement has two synchronous voltage sources with phasors V1pq and V2pq in
series with transmission Lines 1 and 2, represent the two back to back dc to ac
inverters. The common dc link is represented by a bidirectional link (P12=P1pq=P2pq)
for real power exchange between the two voltage sources. Transmission Line-1,
represented by reactance X1, has a sending end bus with voltage phasor V1S and a
receiving end bus with voltage phasor V1R. The sending end voltage phasor of
18

24. Line-2 represented by reactance X2 is V2S and the receiving end voltage phasor is
V2R.
Fig:4.2(b) IPFC with two VSC’s
Transmission relationship between the two systems, system 1 selected to be the
prime system for which free controllability of both real and reactive line power
flow is stipulated. A phasor diagram of system 1, defining the relationship between
V1S,V1R,VX1 (the voltage phasor across X1) and the inserted voltage phasor V1pq
with controllable magnitude (0≤V1pq≤V1pqmax) and angle (0≤ρ1≤360°) is shown in
Fig:2.3. The inserted voltage phasor V1pq is added to the fixed sending end voltage
phasor V1s to produce the effective sending end voltage V1Seff=V1S+V1pq. The
difference V1Seff-V1R provides the compensated voltage phasor, VX1 across X1. As
angle ρ1 is varied over its full 360° range, the end of phase V1pq moves along a
Fig: 4.2(c) IPFC prime converter and corresponding phasor diagram
circle with center located at the end of phasor V1S. The area within this circle
obtained with V1pqmax define the operating range of phase V1pq and thereby the
achievable compensation of Line-1. The rotation of phasor V1pq with angle ρ1
modulates both the magnitude and the angle of phase VX1 and therefore both the
transmitted real power P1R and the reactive power Q1R vary with ρ1 in a sinusoidal
manner. This process requires the voltage source representing Inverter 1 (V1pq) to
supply and absorb both reactive and real power, Q1pq and P1pq which are sinusoidal
function of angle ρ1.
19

25. 4.3 Block diagram of IPFC
Fig-4.3(a) block diagram
4.4 Advantages of IPFC
Interline Power Flow Controller(IPFC) can control the power flow in a multi-
line system. Power imbalance between overloaded lines and under-loaded lines
corrected. Hence minimize the gap between the stability and thermal level.
AC transmission power of a line
P = (Vs * VR * sin δ) /X.
20

26. Three main variables that can be directly controlled to impact its performance are
 Voltage
 Angle
 Impedance
Suitable adjustment of any of these parameters can achieve power flow control in
the transmission line.
Examples of some existing conventional equipment
 Series capacitor – Controls impedance
 Phase shifting transformer – Controls angle
 Switched capacitor and reactor - Controls voltage
 Synchronous condenser - Controls voltage
Traditional approach of using mechanical switch cannot realize full utilization of
the transmission because of the need for large stability margin. Mechanical
switch based operations has more disadvantages. i.e.
 Large stability margin
 Poor dynamic performance
 Non cycling/repeatability
 Discontinuous, not smooth control
 More wear and tear, high rate of failures
21

27. Interline Power Flow Controller (IPFC) FACTS controller has the following
advantages.
 Lower stability margin
 Good dynamic performance
 Cycling/repeatability
 Continuous and smooth control
 Negligible failures
Power electronics based solutions of FACTS controllers are the solution for the
present and future problems of the transmission system.
CHAPTER 5
SIMULATION RESULT AND DISCUSSION
5.1 Introduction
22

28. In order to analyze the IPFC, some simulations are done in this project. The first
simulation was involving the 5 bus system without the consideration of any
FACTS controllers, meaning it was just to measure the system performance
without the FACTS compensation effect. Then, the system performance was
measured with IPFC and effects taken into account. Similarly the simulation of
IEEE 4,8,14,30 bus has been done with and without IPFC.
Fig-5.1(a) Test power system for analyzing the effect of location of IPFC
5.2 Simulation of Base Case (Without IPFC)
23

29. Fig-5.2(a) Test power system without IPFC
24

30. Fig-5.2(b) Real and reactive power generated by generator 1without IPFC
Fig-5.2(c) Real and reactive power generated by generator 2 without IPFC
25

31. Table 1: Bus data obtained from simulation without IPFC
Bus No Voltage(KV) Generation Load
MW MVAR MW MVAR
1 126.2 265.7 143.8 0.0 0.0
2 262.6 0.0 0.0 165.4 82.72
3 256.0 0.0 0.0 157.3 0.0
4 258.6 0.0 0.0 200.6 80.24
5 127.1 268.4 145.5 0.0 0.0
Total 534.1 289.3 523.3 162.96
Table 2: Line data obtained from simulation without IPFC
Line flow and losses
From
Bus
To
Bus
PMW QMVAR From
Bus
To
Bus
PMW QMVAR Line loss
MW MVAR
1 2 277.042 113.812 2 1 -275.2 -87.893 1.842 25.919
1 5 -13.142 -3.312 5 1 13.234 2.104 0.092 -1.208
2 3 109.8 5.173 3 2 -106.9 -0.499 2.9 4.673
4 3 51.03 -9.537 3 4 -50.38 -0.499 0.65 -10.036
5 4 255.166 114.896 4 5 -251.6 -89.77 1.736 25.126
Total 7.22 44.486
Table 3: Losses in transformer1&2 without IPFC
Transformer Transformer losses
MW MVAR
1 1.8 33.3
2 1.8 28.5
Total 3.6 61.8
Total losses: 10.82 MW, 106.286 MVAR
26

32. 5.3 Test power system with IPFC between line 1 and 2 at bus1
Fig-5.3(a) Test power system with IPFC between line 1 and 2 at bus1
27

33. Fig-5.3(b) Real and reactive power generated by generator 1 with IPFC
Fig-5.3(c) Real and reactive power generated by generator 2 with IPFC
28

34. 29

35. Table 4: Bus data obtained from simulation with IPFC at bus 1
Bus No Voltage(KV) Generation Load
MW MVAR MW MVAR
1 129.5 281 161.4 0.0 0.0
2 267.7 0.0 0.0 172 85.98
3 260.5 0.0 0.0 162.9 0
4 262.6 0.0 0.0 206.9 82.74
5 128.8 271.8 138.3 0.0 0.0
Total 552.8 299.7 541.8 168.72
Table 5: Line data obtained from simulation with IPFC at bus 1
Line flow and losses
From
Bus
To
Bus
PMW QMVAR From
Bus
To
Bus
PMW QMVAR Line loss
MW MVAR
1 2 287.964 121.768 2 1 -286.1 88.09 1.864 33.678
1 5 -8.864 3.132 5 1 8.936 -8.804 0.072 -5.672
2 3 114.1 2.112 3 2 -111.1 -2.718 3.0 0.606
4 3 52.45 2.718 3 4 -51.77 -13.08 0.68 -10.362
5 4 261.164 119.198 4 5 -259.3 95.82 1.814 23.378
Total 7.43 41.628
Table 6: Losses in transformer1&2 with IPFC at bus 1
Transformer Transformer losses
MW MVAR
1 1.9 36.5
2 1.7 27.9
Total 3.6 64.4
Total losses: 11.03 MW, 106.028 MVAR
30

36. 5.4 Test power system with IPFC between line 1 and 2 at bus 5
Fig-5.4(a) Test power system with IPFC between line 1 and 2 at bus 5
31

37. 32

38. Fig-5.4(b) Real and reactive power generated by generator 1 with IPFC
Fig-5.4(c) Real and reactive power generated by generator 2 with IPFC
33

39. Table 7: Bus data obtained from simulation with IPFC at bus5
Bus No Voltage(KV) Generation Load
MW MVAR MW MVAR
1 127.8 273 140.1 0.0 0.0
2 266.4 0.0 0.0 170.3 85.13
3 260.4 0.0 0.0 162.8 0.0
4 263.7 0.0 0.0 208.7 83.46
5 130.0 279.8 159.6 0.0 0.0
Total 552.8 299.7 541.8 168.51
Table 8: Line data obtained from simulation with IPFC at bus5
Line flow and losses
From
Bus
To
Bus
PMW QMVAR From
Bus
To
Bus
PMW QMVAR Line loss
MW MVAR
1 2 283.81 112.622 2 1 -282.1 -94.37 1.71 17.63
1 5 -12.61 -6.223 5 1 12.724 3.059 0.114 -3.164
2 3 111.7 9.236 3 2 -108.8 -4.227 2.9 5.009
4 3 54.69 -6.087 3 4 -53.97 -4.227 0.72 -10.314
5 4 265.28 126.24 4 5 -263.4 -89.547 1.89 36.693
Total 7.334 45.845
Table 9: Losses in transformer1&2
Transformer Transformer losses
MW MVAR
1 1.8 33.7
2 1.8 30.3
Total 3.6 67
Total losses: 10.93 MW, 112.845 MVAR
5.5 Test power system with IPFC between line 1 and 3
34

40. Fig-5.5(a) Test power system with IPFC between line 1 and 3
35

41. Fig-5.5(b) Real and reactive power generated by generator 1 with IPFC
Fig-5.5(c) Real and reactive power generated by generator 2 with IPFC
36

42. 37

43. Table 10: Bus data obtained from simulation with IPFC between line 1&3
Bus No Voltage(KV) Generation Load
MW MVAR MW MVAR
1 126.5 291.5 168.2 0.0 0.0
2 271.3 0.0 0.0 176.7 88.34
3 264.0 0.0 0.0 167.3 0.0
4 266.2 0.0 0.0 212.6 85.03
5 127.0 276.7 149.5 0.0 0.0
Total 568.2 317.7 556.6 173.37
Table 11: Line data obtained from simulation with IPFC between line 1&3
Line flow and losses
From
Bus
To
Bus
PMW QMVAR From
Bus
To
Bus
PMW QMVAR Line loss
MW MVAR
1 2 299.49 129.80 2 1 -297.4 -92.07 2.092 37.73
1 5 -9.992 2.001 5 1 10.075 -7.475 0.082 -5.474
2 3 120.7 -3.729 3 2 -117.4 7.635 3.3 3.906
4 3 50.42 11.63 3 4 -49.81 -0.7635 0.61 -10.86
5 4 264.926 111.725 4 5 -263.0 -96.66 1.926 25.06
Total 8.01 50.362
Table 12: Losses in transformer1&2
Transformer Transformer losses
MW MVAR
1 2 40
2 1.7 30.3
Total 3.7 70.3
Total losses: 11.71 MW, 121.062 MVAR
38

44. 5.6Test power system with IPFC between line 2 and 3
Fig-5.6(a) Test power system with IPFC between line 2 and 3
39

45. Fig-5.6(b) Real and reactive power generated by generator 1 with IPFC
Fig-5.6(c) Real and reactive power generated by generator 2 with IPFC
40

46. 41

47. Table 13: Bus data obtained from simulation with IPFC between line 2&3
Bus No Voltage(KV) Generation Load
MW MVAR MW MVAR
1 126.5 291.5 168.2 0.0 0.0
2 271.3 0.0 0.0 176.7 88.34
3 264.0 0.0 0.0 167.3 0.0
4 266.2 0.0 0.0 212.6 85.03
5 127.0 276.7 149.5 0.0 0.0
Total 568.2 317.7 556.6 173.37
Table 14: Line data obtained from simulation with IPFC between line 2&3
Line flow and losses
From
Bus
To
Bus
PMW QMVAR From
Bus
To
Bus
PMW QMVAR Line loss
MW MVAR
1 2 299.49 129.80 2 1 -297.4 -92.07 2.092 37.73
1 5 -9.992 2.001 5 1 10.075 -7.475 0.082 -5.474
2 3 120.7 -3.729 3 2 -117.4 7.635 3.3 3.906
4 3 50.42 11.63 3 4 -49.81 -0.7635 0.61 -10.86
5 4 264.926 111.725 4 5 -263.0 -96.66 1.926 25.06
Total 8.01 50.362
Table 15: Losses in transformer1&2
Transformer Transformer losses
MW MVAR
1 2 40.4
2 1.7 30.3
Total 3.7 70.7
Total losses: 11.71 MW, 121.062 MVAR
42

48. 5.7 Test power system with IPFC between line 1 and 4
Fig-5.7(a)Test power system with IPFC between line 1 and 4
43

49. Fig-5.7(b) Real and reactive power generated by generator 1 with IPFC
Fig-5.7(c) Real and reactive power generated by generator 2 with IPFC
44

50. Table 16: Bus data obtained from simulation with IPFC between line 1&4
Bus No Voltage(KV) Generation Load
MW MVAR MW MVAR
1 125.9 281.9 149.9 0.0 0.0
2 270.6 0.0 0.0 175.8 87.88
3 264.5 0.0 0.0 167.9 0.0
4 268.0 0.0 0.0 215.5 86.18
5 128.3 288.9 170.3 0.0 0.0
Total 570.8 320.2 559.2 174.06
Table17: Line data obtained from simulation with IPFC between line 1&4
Line flow and losses
From
Bus
To
Bus
PMW QMVAR From
Bus
To
Bus
PMW QMVAR Line loss
MW MVAR
1 2 291.96 119.357 2 1 -290.1 96.67 1.867 22.287
1 5 -11.967 -6.657 5 1 12.074 3.633 0.107 -3.024
2 3 114.3 8.796 3 2 -111.3 -3.491 3.0 5.305
4 3 57.4 -7.08 3 4 -56.63 3.491 0.77 -3.589
5 4 274.926 133.367 4 5 -
272.90
-93.27 2.026 40.107
Total 7.77 61.08
Table 18: Losses in transformer1&2
Transformer Transformer losses
MW MVAR
1 1.9 37.2
2 1.9 33.3
Total 3.8 70.5
45

51. Total losses: 11.57 MW,131.586 MVAR
5.8 Test power system with IPFC between line 2 and 4
46

52. Fig-5.8(a) Test power system with IPFC between line 2 and 4
Fig-5.8(b) Real and reactive power generated by generator 1 with IPFC
47

53. Fig-5.8(c) Real and reactive power generated by generator 2 with IPFC
48

54. Table 19: Bus data obtained from simulation with IPFC between line 2&4
Bus No Voltage(KV) Generation Load
MW MVAR MW MVAR
1 125.9 281.9 149.9 0.0 0.0
2 270.6 0.0 0.0 175.8 87.88
3 264.5 0.0 0.0 167.9 0.0
4 268.0 0.0 0.0 215.5 86.18
5 128.3 288.9 170.3 0.0 0.0
Total 570.8 320.2 559.2 174.06
Table 20: Line data obtained from simulation with IPFC between line 2&4
Line flow and losses
From
Bus
To
Bus
PMW QMVAR From
Bus
To
Bus
PMW QMVAR Line loss
MW MVAR
1 2 291.96 119.357 2 1 -290.1 96.67 1.867 22.287
1 5 -11.967 -6.657 5 1 12.074 3.633 0.107 -3.024
2 3 114.3 8.796 3 2 -111.3 -3.491 3.0 5.305
4 3 57.4 -7.08 3 4 -56.63 3.491 0.77 -3.589
5 4 274.926 133.367 4 5 -272.9 -93.27 2.026 40.107
Total 7.77 61.086
Table 21: Losses in transformer1&2
Transformer Transformer losses
MW MVAR
1 1.9 37.2
2 1.9 33.3
Total 3.8 70.5
Total losses:11.57 MW, 131.586 MVAR
5.8.1DISCUSSION
49

55. Several simulations have been ran, and the performance of IPFC controllers used
have been evaluated. Transmitted powers in each line is a function of the voltage
amplitude of sending end and receiving buses, phase shift of sending and receiving
end buses, and series impedance of the line. IPFC can directly or indirectly impact
on each of these factors, and increase the power transfer capability of the line.
Therefore, it could be concluded that IPFC would improves the maximum power
transfer level in the case when IPFC is installed between line 1 and 4 or between
line 2 and 4 because of symmetry.
Hence from the simulation result optimal location of interline power flow
controller (IPFC) should be at the line 1and 4 or line 2 and 4.
50

56. 5.9 Four bus system
Fig-5.9(a) four bus system without IPFC
51

57. Fig-5.9(b) Real and reactive power in bus-1
Fig-5.9(c) Real and reactive power in bus-2
Fig-5.9(d) Real and reactive power in bus-3
52

58. Fig-5.9(e) 4 bus line model with IPFC
53

59. Fig-5.9(f) IPFC model
Fig-5.9(g) Real and reactive power in bus-1
54

60. Fig-5.9(h) Real and reactive power in bus-2
Fig-5.9(i) Real and reactive power in bus-3
TABLE 22: Real and Reactive power with and without IPFC in 4 bus system.
BUS NO REAL POWER( MW)
WITHOUT
COMPENSATION
REAL POWER( MW)
WITH
COMPENSATION
REACTIVE POWER
( MVA)
WITHOUT
COMPENSATION
REACTIVE POWER
( MVA)
WITH
COMPENSATION
BUS-1 6.084e5 2.404e5 2.27e5 8.728e4
BUS-2 1.336e5 1.814e5 2.098e4 2.85e4
BUS-3 2.4e5 2.96e5 7.539e4 9.298e4
55

61. 56

62. 5.10 8 bus line model
Fig-5.10(a) 8 bus line model without IPFC
Fig-5.10(b) Real and reactive power in bus-1
57

63. Fig-5.10(c) Real and reactive power in bus-6
Fig-5.10(d) Real and reactive power in bus-7
58

64. Fig-5.10(e) 8 bus system with IPFC
59

65. Fig-5.10(f) IPFC model
Fig-5.10(g) Real and reactive power in bus-1
60

66. Fig-5.10(h) Real and reactive power in bus-6
Fig-5.10(i) Real and reactive power in bus-7
TABLE 23:Real and Reactive power with and without IPFC in 8 bus system.
BUS NO REAL POWER( MW)
WITHOUT
COMPENSATION
REAL POWER( MW)
WITH
COMPENSATION
REACTIVE POWER
( MVA)
WITHOUT
COMPENSATION
REACTIVE POWER
( MVA)
WITH
COMPENSATION
BUS-1 0.1422 0.1465 0.0400 0.0313
BUS-6 0.0280 0.0287 0.1823 0.183
61

67. BUS-7 0.327 0.321 0.103 0.105
BUS-8 0.198 0.200 0.0414 0.0423
BUS-2 0.1797 0.181 0.0282 0.0284
62

68. 5.11- 14 bus line model
Fig-5.11(a) 14 bus system without IPFC
63

69. Fig-5.11(b) voltage across bus -3
Fig-5.11(c) Real and reactive power across bus-3
Fig-5.11(d) Voltage across bus-11
64

70. Fig-5.11(e) Real and reactive power across bus-11
Fig-5.11(f) 14 bus system with IPFC
65

71. Fig-5.11(g) Voltage across bus-3
Fig-5.11(h) Real and reactive power across bus-3
66

72. Fig-5.11(i) Voltage across bus-11
Fig-5.11(j) Real and reactive power across bus-11
TABLE 24:Real and Reactive power with and without IPFC in 14 bus system.
BUS NO REAL POWER WITHOUT
IPFC (MW)
REAL POWER WITH
IPFC (MW)
REACTIVE POWER
WITHOUT IPFC
(MVAR)
REACTIVE
POWER WITH
IPFC (MVAR)
BUS-7 0.214 0.306 0.242 0.558
BUS-1 0.247 0.2337 0.258 0.245
67

73. BUS-3 0.328 0.491 1.033 1.542
BUS-11 0.13 0.39 0.0136 0.41
68

74. 5.12 30 Bus line model
Fig-5.12(a) IEEE 30 BUS SYSTEMS
69

75. Fig-5.12(b) Voltage across bus-11
Fig-5.12(c) Real power at bus-11
Fig-5.12(d) Reactive power at bus-11
70

76. Fig-5.12(e) IEEE 30 bus system with IPFC
Fig-5.12(f) Voltage across buss-11
71

77. Fig-5.12(g) Real power at bus-11
Fig-5.12(h) Reactive power at bus-11
TABLE 25:Real and Reactive power with and without IPFC in 30 bus system.
Bus no P (MW)
without
IPFC
P (MW) with
IPFC
Q (MVAR)
without
IPFC
Q (MVAR)
with
IPFC
VOLTAGE
(V) without
IPFC
VOLTAGE
(V) with IPFC
5 0.212 0.208 0.099 0.098 7198 7144
11 0.418 0.421 0.131 0.132 6783 6798
12 0.35 0.36 1.482 1.51 6868 6931
13 0.338 0.344 1.065 1.08 6069 6112
19 0.341 0.346 0.134 0.136 6868 6931
21 0.286 0.31 0.0934 0.101 6295 6540
72

78. CHAPTER 6
CONCLUSIONS AND SUGGESTIONS FOR FUTURE STUDY
6.1 Conclusions
Several simulations have been ran, and the performance of IPFC controllers used
have been evaluated. Transmitted powers in each line is a function of the voltage
amplitude of sending end and receiving buses, phase shift of sending and receiving
end buses, and series impedance of the line. IPFC can directly or indirectly impact
on each of these factors, and increase the power transfer capability of the line.
Therefore, it could be concluded that IPFC would improves some of the power
system parameters.
Based on the results obtained, IPFC improved the voltage profile of the bus at
which has the lowest PV curve. This improvement was in terms of to maintain the
voltage steady approximately at 1 p.u. with the increasing of load and also to
support the bus when the voltage collapses. IPFC is able to transfer real power
between compensated lines in addition to compensate reactive power for each
individual line, independently. So it can equalize both real and reactive power flow
between the lines, transfer power demand from overloaded to under loaded
Lines, compensate against resistive voltage drops, and increase the effectiveness of
the system for dynamic disturbances.
73

79. 6.2 Suggestions for Future Study
There are several suggestions for future study, and these are:
i. The IPFC should be tested on a very large network, to view its capability
handling complex network.
ii. The IPFC should be tested with respect to dynamic machine, to observe its
effect to machine dynamic performance.
iii. More type of FACTS Controllers should be used, and hence could observe and
compare the difference with interline power flow Controllers.
74

80. REFERENCES
1. Understanding FACTS Concepts and Technology of Flexible AC
Transmission Systems Narain G. Hingoranl Hingorani Power Electronics
Los Altos Hills, CA Laszlo Gyugyi Siemens Power Transmission &
Distribution Orlando, FL Mohamed E. El-Hawary, Consulting Editor IEEE
Power Engineering Society.
2. FACTS CONTROLLERS IN POWER TRANSMISSION AND
DISTRIBUTION K. R. Padiyar Department of Electrical Engineering
Indian Institute of Science Bangalore-560 012 India.
3. An Overview of Flexible AC Transmission Systems P. Asare Purdue
University School of Electrical Engineering T. Diez Purdue University School
of Electrical Engineering A. Galli Purdue University School of Electrical
Engineering E. O'Neill-Carillo Purdue University School of Electrical
Engineering J. Robertson Purdue University School of Electrical Engineering.
4. M. Fekri Moghadam, H. Askarian Abyaneh , S. H.Fathi Department of
Electrical Engineering Amirkabir University of Technology Tehran, Iran ,M.
Khederzadeh Department of Electrical Engineering Power & Water
University of Technology Tehran, Iran 978-1-4244-8756-1/11/ 2011 IEEE
75

81. 5. A Hybrid Technique for Controlling Multi Line Transmission System Using
Interline Power Flow Controllern B. Karthik Lecturer, Department of
Electrical and Electronics EngineeringSona College of Technology, Salem,
Tamilnadu, India European Journal of Scientific Research ISSN 1450-216X
Vol.58 No.1 (2011), pp.59-76 EuroJournals Publishing, Inc.
2011http://www.eurojournals.com/ejsr.htm
6. Digital Simulation of Thirty Bus System with Interline Power Flow
Controller G. Irusapparajan and S. Rama Reddy International Journal of
Computer and Electrical Engineering, Vol. 3, No. 4, August 2011
7. Modeling and Digital Simulation of Interline Power Flow Controller System
P.Usha Rani and B. S.Rama Reddy International Journal of Computer and
Electrical Engineering, Vol. 2, No. 3, June, 2010 1793-8163
8. Damping Performance Analysis of IPFC and UPFC Controllers Using
Validated Small-Signal Models Shan Jiang, Student Member, IEEE, Ani M.
Gole, Fellow, IEEE, Udaya D. Annakkage, Senior Member, IEEE, and D. A.
Jacobson, Senior Member, IEEE
9. Dynamic Modeling of Interline Power Flow Controller for Small Signal
Stability Alivelu M. Parimi, Nirod C. Sahoo, Irraivan Elamvazuthi, Nordin
Saad Electrical and Electronics Department Universiti Teknologi
PETRONAS, Tronoh 31750, Perak, Malaysia.
76

82. 10. Interline Photovoltaic (I-PV) Power System – A Novel Concept of Power
Flow Control and Management Vinod Khadkikar, Member, IEEE, and James
L. Kirtley, Jr., Fellow, IEEE
.
77

83. 1.
78

84. 79