of large interconnected networks had fluctuations in reliability of power supply, ... shifting transformer (PST) and the Static VAR Compensator (SVC) are already ...
ISSN: 2319-5967 ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 3, Issue 5, September 2014
Power Quality Enhancement of Standard IEEE 14 Bus System using Unified Power Flow Controller Shraddha S. Khonde1, S. S. Dhamse2, Dr. A. G. Thosar3 Abstract—The demand for electricity generation is quickly blooming as the use of electricity and other distributed power generation systems have drastically increased. With the demand of electricity, at times, it is not possible to set new lines to face the situation. Growth of electrical energy consumptions and increasing non-linear loads in power systems force the electrical power utilities to provide a high electrical power, and this is the reason that this issue is getting more and more significance in power systems. In Electrical Power System for governing, UPFC is the most complex but promising power electronics system. In this paper, Unified Power Flow Controller is studied to improve the power flow over a transmission line in a standard IEEE 14 bus system by using MATLAB / SIMULINK in a power system block set. For the selected standard system, real and reactive power flows are compared with and without UPFC to prove the performance. Active and reactive power through the transmission line cannot be controlled without UPFC but with the circuit model for UPFC using rectifier and inverter circuits, this performance gets improved. In this paper implementation and digital simulation using UPFC to improve the power quality is presented. The MATLAB/SIMULINK model results are presented to verify the results. Index Terms—FACTS, IEEE 14 Bus system, Power Flow, Power Quality, UPFC.
I. INTRODUCTION The technology of power system utilities around the world has rapidly evolved with considerable changes in the technology along with improvements in power system structures and operation. The ongoing expansions and growth in the technology, demand a more optimal and profitable operation of a power system with respect to generation, transmission and distribution systems. Power Systems Engineering Committee of the industrial and commercial power systems department of the IEEE Industry Applications society (1999) develops IEEE Standard 1100-1999 which recommended Practice for Powering and Grounding Electronic Equipment Power Quality is defined in the IEEE 100 Authoritative Dictionary of IEEE Standard terms as “ the concept of powering and grounding electronic equipment in a manner that it is suitable to the operation of that equipment and compatible with the premise wiring systems and other connected equipment .” Power Quality is the combination of voltage quality and current quality. Quality of supply is a combination of voltage quality and the non-technical aspects of the interaction from the power network to its customers. Quality of consumption is the complementary terms to Quality of supply Power Quality (PQ) is an issue that is becoming increasingly important to electricity consumers at all levels of usage. Sensitive equipment and non-linear loads are commonplace in both the industrial and the domestic environment; because of this a heightened awareness of power quality is developing. The sources of problems that can disturb the power quality are: power electronic devices, arcing devices, load switching, large motor starting, embedded generation, sensitive equipment, storm and environment related damage, network equipment and design. The solution to improve the power quality at the load side is of great important when the production processes get more complicated and require a bigger liability level, which includes aims like to provide energy without interruption, without harmonic distortion and with tension regulation between very narrow margins. In the present scenario, most of the power systems in the developing countries with large interconnected networks share the generation reserves to increase the reliability of the power system. However, the increasing complexities of large interconnected networks had fluctuations in reliability of power supply, which resulted in system instability, difficult to control the power flow and security problems that resulted large number blackouts in different parts of the world. The reasons behind the above fault sequences may be due to the systematic errors in
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ISSN: 2319-5967 ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 3, Issue 5, September 2014 planning and operation, weak interconnection of the power system, lack of maintenance or due to overload of the network. In order to overcome these consequences and to provide the desired power flow along with system stability and reliability, installations of new transmission lines are required. However, installation of new transmission lines with the large interconnected power system are limited to some of the factor like economic cost, environment related issues. These complexities in installing new transmission lines in a power system challenges the power engineers to research on the ways to increase the power flow with the existing transmission line without reduction in system stability and security. In this research process, in the late 1980’s the Electric Power Research Institute (EPRI) introduced a concept of technology to improve the power flow, improve the system stability and reliability with the existing power systems. This technology of power electronic devices is termed as Flexible Alternating Current Transmission Systems (FACTS) technology. It provides the ability to increase the controllability and to improve the transmission system operation in terms of power flow, stability limits with advanced control technologies in the existing power systems. The main objective to introduce FACTS Technology is as follows: To increase the power transfer capability of transmission network in a power system. To provide the direct control of power flow over designated transmission routes. To provide secure loading of a transmission lines near the thermal limits. To improve the damping of oscillations as this can threaten security or limit usage line capacity. FACTS technology is not a single power electronic device but a collection of controllers that are applied individually or in coordination with other devices to control one or more interrelated power system parameters such as series impedance, shunt impedance, current, voltage and damping of oscillations. These controllers were designed based on the concept of FACTS technology known as FACTS Controllers. FACTS controllers are advanced in relation to mechanical control switched systems that are controlled with ease. They have the ability to control the power flow and improve the performance of the power system without changing the topology. Since 1980s, a number of different FACTS controllers with advanced control techniques proposed as per the demand of the power systems. Unified Power Flow Controller (UPFC) is one among the different FACTS controllers introduced to improve the power flow control with stability and reliability. It is the most versatile device introduced in early 1990s designed based on the concept of combined series-shunt FACTS Controller. It has the ability to simultaneously control all the transmission parameters affecting the power flow of a transmission line i.e. voltage, line impedance and phase angle. II. FACTS CONTROLLER FACTS is defined by the IEEE as "a power electronic based system and other static equipment that provide control of one or more AC transmission system and increase the capacity of power transfer.” The FACTS devices can be divided in three groups, dependent on their switching technology: Mechanically switched (such as phase shifting transformers), thyristor switched or fast switched, using IGBTs. While some types of FACTS, such as the phase shifting transformer (PST) and the Static VAR Compensator (SVC) are already well known and used in power systems, new developments in power electronics and control have extended the application range of FACTS. Furthermore, intermittent renewable energy sources and increasing international power flows provide new applications for FACTS. The additional flexibility and controllability of FACTS allow mitigating the problems associated with the unreliable of supply issues of renewable. SVCs and STATCOM devices are well suited to provide ancillary services (such as voltage control) to the grid and fault ride through capabilities which standard wind farms cannot provide Furthermore, FACTS reduce oscillations in the grid, which is especially interesting when dealing with the stochastic behavior of renewable. In a liberalized market, the added value of FACTS, and especially power flow controlling devices, is the ability to control flow paths and therefore the ability to resolve congestions and optimally utilizing available grid infrastructure. Although FACTS devices are currently quite expensive, it is expected that with a growing utilization and experience, prices will drop considerably.
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ISSN: 2319-5967 ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 3, Issue 5, September 2014 II. BENEFITS OF UTILIZING FACTS DEVICES The benefits of utilizing FACTS devices in electrical transmission systems can be summarized as follows: - Better utilization of existing transmission system assets. - Increased transmission system reliability and availability. - Increased dynamic and transient grid stability and reduction of loop flows. - Increased quality of supply for sensitive industries. - Environmental benefits Better utilization of existing transmission system assets. In many countries, increasing the energy transfer capacity and controlling the load flow of transmission lines are of vital importance, especially in de-regulated markets, where the locations of generation and the bulk load centres can change rapidly. Frequently, adding new transmission lines to meet increasing electricity demand is limited by economical and environmental constraints. FACTS devices help to meet these requirements with the existing transmission systems. Table A. Detail classification of FACT devices is given in following table: FACTS - Devices (f ast, Static)
Conventional (Switched)
R, L, C Transf ormer
Thyristor valve
Voltage Source Converter (VSC)
Shunt Devices
Switched Shunt Compensation (LC)
Static Var Compensator SVC
Static Synchronous Compensator STATCOM
Series Devices
(Switched) Series Compensation (LC)
Thyristor Controlled Series Compensator TCSC
Static Synchronous Series Compensator SSSC
Phase Shif ting Transf ormer
Dynamic Flow Controller DFC
Unif ied/ Interline Power Flow Controller UPFC / IPFC
HVDC B ack to B ack (HDVC B 2B )
HVDC VSC B ack to B ack (HDVC VSC B 2B )
Shunt and Series Devices Shunt and Series Devices
III. UNIFIED POWER FLOW CONTROLLER (UPFC) Among all the FACTS devices the most flexible and universal device is unified power flow controller ( UPFC ). It is a combination of three compensator’s characteristics, i.e. impedance, voltage magnitude and phase angle, that are able to produce a more complete compensation. By controlling impedance, voltage magnitude, phase angle Unified power flow controller (UPFC) is used to control the power flow in the transmission systems. This controller brings in new challenges power electronics and power system design. In terms of static and dynamic operation of the power system this controller also offers advantages. The basic structure consists of two Voltage Source Inverter’s ( VSI’s ); where one converter is connected in series with transmission line while other converter is connected in parallel to the transmission line.
A. Construction of UPFC The UPFC consists of two voltage source converters; series and shunt converter, which are connected to each other with a common dc link. Shunt converter or Static Synchronous Compensator (STATCOM) is used to provide reactive power to the ac system, beside that, it will provide the dc power required for both inverter, while series converter or Static Synchronous Series Compensator (SSSC) is used to add controlled voltage magnitude and phase angle in series with the line. Each of the branches consists of a transformer and power electronic converter. These two voltage source converters shared a common dc capacitor. The energy storing capacity of this dc capacitor is generally small. Therefore, active power drawn by the shunt converter should be equal to the active power generated by the series converter. The reactive power in the shunt or
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ISSN: 2319-5967 ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 3, Issue 5, September 2014 series converter can be chosen independently, giving greater flexibility to the power flow control. The coupling transformer is used to connect the device to the system.
Fig 1. Schematic diagram of the three phase UPFC connected to the transmission line m
*
Vl
Vl
Vlf
Fundamental component calculator
+
-
Voltage Magnitude Calculator
+ PI Controller
+
Vsin comparator
PLL
+
Vtri
+
VDC
* VDC
msh
PI Controller
-
and firing pulse Firing pulses generator for IGBT pairs
COS
+
-
+v 0 -v
Fig 2. Block diagram of shunt inverter controller m
Qline Qline
Vl
Fundamental component calculator
-
+
+ PI Controller
+
Vlf
Vsin
PLL
Pline
PI Controller
-
+
Vtri
COS
-
+v 0 -v
Fig 3. Block diagram of series inverter controller
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comparator and firing pulse Firing Pulses generator
for IGBT Pairs
+
Pline
+
msh
ISSN: 2319-5967 ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 3, Issue 5, September 2014
Fig 4. Single line diagram of UPFC and Phasor of voltage and current
Figure 1 shows the schematic diagram of the three phase UPFC connected to the transmission line[14]. Figure 2 shows the block diagram of shunt inverter controller and Figure 3 shows the block diagram of series inverter controller [16]. Control of power flow is achieved by adding the series voltage, VS with a certain amplitude, ∣ VS ∣ and phase shift, φ. Figure 4 shows Single line diagram of UPFC and Phasor of voltage and current to V1[17]. This gives a new line voltage V2 with different magnitude and phase shift. As the angle φ varies, the phase shift δ between V2 and V3 also varies. Voltage and current. With the presence of the two converters, UPFC not only can supply reactive power but also active power. The equation for the active and reactive power is given as follows:-
(1)
(2) B. Characteristics of UPFC Line outage, congestion, cascading line tripping, power system stability loss are the major issues where capability and utilization of FACTS are noticed. Representative of the last generation of FACTS devices is the Unified Power Flow Controller (UPFC). The UPFC is a device which can control simultaneously all three parameters of line power flow (line impedance, voltage and phase angle). Such "new" FACTS device combines together the features of two "old" FACTS devices: the Static Synchronous Compensator (STATCOM) and the Static Synchronous Series Compensator (SSSC). In practice, these two devices are two Voltage Source Inverters (VSI’s) connected respectively in shunt with the transmission line through a shunt transformer and in series with the transmission line through a series transformer, connected to each other by a common dc link including a storage capacitor. The shunt inverter is used for voltage regulation at the point of connection injecting an opportune reactive power flow into the line and to balance the real power flow. The series inverter is controlled to inject a symmetrical three phase voltage system (V), of controllable magnitude and phase angle in series with the line to control active and reactive power flows on the transmission line. So, this inverter will exchange active and reactive power with the line. The reactive power is electronically provided by the series inverter, and the active power is transmitted to the dc terminals. The shunt inverter is operated in such a way as to demand this dc terminal power (positive or negative) from the line keeping the voltage across the storage capacitor Vdc constant. So, the net real power absorbed from the line by the UPFC is equal only to the losses of the inverters and their transformers. The remaining capacity of the shunt inverter can be used to exchange reactive power with the line so to provide a voltage regulation at the connection point. The two VSI’s can work independently of each other by separating the dc side. So in that case, the shunt inverter is operating as a STATCOM (Static Synchronous Compensators) that generates or absorbs reactive power to regulate the voltage magnitude at the connection point. Instead, the series inverter is operating as SSSC (Static
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ISSN: 2319-5967 ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 3, Issue 5, September 2014 Synchronous Series Compensators) that generates or absorbs reactive power to regulate the current flow, and hence the power flows on the transmission line. C. Operating modes of UPFC The UPFC has many possible operating modes. In particular, the shunt inverter is operating in such a way to inject a controllable current, into the transmission line. This current consists of two components with respect to the line voltage: the real or direct component, which is in phase or in opposite phase with the line voltage, and the reactive or quadrature component, which is in quadrature. The direct component is automatically determined by the requirement to balance the real power of the series inverter. The quadrature component, instead, can be independently set to any desired reference level (inductive or capacitive) within the capability of the inverter, to absorb or generate respectively reactive power from the line. The shunt inverter can be controlled in two different modes: VAR Control Mode: The reference input is an inductive or capacitive VAR request. The shunt inverter control translates the VAR reference into a corresponding shunt current request and adjusts gating of the inverter to establish the desired current. For this mode of control a feedback signal representing the dc bus voltage, V dc, is also required. Automatic Voltage Control Mode: The shunt inverter reactive current is automatically regulated to maintain the transmission line voltage at the point of connection to a reference value. For this mode of control, voltage feedback signals are obtained from the sending end bus feeding the shunt coupling transformer. The series inverter controls the magnitude and angle of the voltage injected in series with the line to influence the power flow on the line. The actual value of the injected voltage can be obtained in several ways. Direct Voltage Injection Mode: The reference inputs are directly the magnitude and phase angle of the series voltage. Phase Angle Shifter Emulation Mode: The reference input is phase displacement between the sending end voltage and the receiving end voltage. Line Impedance Emulation Mode: The reference input is an impedance value to insert in series with the line impedance. IV. SIMULATION AND RESULTS By using MATLAB / SIMULINK digital simulation is being done and accordingly results are presented. In Figure 5 Standard IEEE 14 bus system is shown. Figure 6 shows the simulation model of IEEE 14 bus system in MATLAB / SIMULINK. The SIMULINK model of IEEE 14 bus system with Unified power flow controller is presented in Figure 7. Specific waveforms are given in the figures. In the transmission line approximate performance evaluation with and without unified power flow controller has been studied. Series RL combination represent the line impedance. The waveform of output voltage across load 1 and load 2 without UPFC is presented in Figure 8 and Figure 9 and the waveform of output voltage across load 1 and load 2 with UPFC in Figure 10 and Figure 11. Figure 12 shows the active and reactive power with and without UPFC. These waveforms are obtained by simulating the SIMULINK diagram for test system in the environment of Sim Power Systems toolbox of MATLAB. Ode 23tb [stiff/TR-BDF2] solver is used as developed SIMULINK model involves nonlinear elements. The magnitude of voltage at bus 1 is conformed to 1.06 per unit. Line impedances are taken in per unit on a 100-MVA base. The power injections at the corresponding buses and increment in the power at corresponding buses can be observed in Table B and we can observe the hike in the active power at the corresponding buses. Transformer tap setting data for IEEE 14 bus system is given in Table C. Bus Data and Load Flow Results – IEEE 14 Bus system are given in table D. Table E shows the bus data and load flow result for bus 1-14.
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ISSN: 2319-5967 ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 3, Issue 5, September 2014
Fig 5. Standard IEEE – 14 Bus test system
Fig 6. SIMULINK model of IEEE – 14 Bus system
Fig 7. Standard IEEE – 14 Bus system with UPFC
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ISSN: 2319-5967 ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 3, Issue 5, September 2014 Without UPFC 1.5
1
Voltage
0.5
0
-0.5
-1
-1.5
0
0.1
0.2
0.3
0.4 Time in sec
0.5
0.6
0.7
0.8
Fig 8. Voltage (pu) across load – 1 without UPFC. Without UPFC 1.5
1
Voltage
0.5
0
-0.5
-1
-1.5
0
0.1
0.2
0.3
0.4 Time
0.5
0.6
0.7
0.8
Fig 9. Voltage (pu) across load – 2 without UPFC. With UPFC 1.5
1
Voltage
0.5
0
-0.5
-1
-1.5
0
0.1
0.2
0.3
0.4
0.5 Time in sec
0.6
0.7
0.8
0.9
1
Fig 10. Voltage (pu) across load – 1 with UPFC. With UPFC 1.5
1
Voltage
0.5
0
-0.5
-1
-1.5
0
0.1
0.2
0.3
0.4
0.5 Time in sec
0.6
0.7
Fig 11. Voltage (pu) across load – 2 with UPFC.
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0.8
0.9
1
ISSN: 2319-5967 ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 3, Issue 5, September 2014 Table B. Power Flows with and without UPFC Gen
Power flow without UPFC
Power flow with UPFC
P (pu)
Q (pu)
P (pu)
Q (pu)
G1
2.118
0.140
2.336
0.028
G2
2.327
-0.949
1.129
0.843
P and Q (pu) for G1 with and without UPFC 2.5
2 P(pu) without UPFC Q(pu) with UPFC P(pu) with UPFC Q(pu) without UPFC
P (pu) and Q (pu)
1.5
1
0.5
0
-0.5 0
0.1
0.2
0.3
0.4 Time in sec
0.5
0.6
0.7
Fig 12. Active and Reactive power (pu) from GI with and without UPFC. Table C. Transformer Tap setting data – IEEE 14 Bus system From bus
To bus
Tap setting value (p.u.)
4
7
0.978
4
9
0.969
5
6
0.932
331
0.8
ISSN: 2319-5967 ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 3, Issue 5, September 2014 Table D. Line Data – IEEE 14 Bus system Line Impedance (p.µ)
Line No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
From Bus 1 1 2 2 2 3 4 4 4 5 6 6 6 7 7 9 9 10 12
To Bus 2 5 3 4 5 4 5 7 9 6 11 12 13 8 9 10 14 11 13
Resistance 0.0.1938 0.05403 0.04699 0.05811 0.05695 0.06701 0.01335 0 0 0 0.09498 0.12291 0.06615 0 0 0.03181 0.12711 0.08205 0.22092
Reactance 0.05917 0.22304 0.19797 0.17632 0.17388 0.17103 0.04211 0.20912 0.55618 0.25202 0.1989 0.25581 0.13027 0.17615 0.11001 0.0845 0.27038 0.19207 0.19988
Half Line Charging Susceptance (p. µ) 0.02640 0.02190 0.01870 0.02460 0.01700 0.01730 0.00640 0 0 0 0 0 0 0 0 0 0 0 0
MVA Rating 120 65 36 65 50 65 45 55 32 45 18 32 32 32 32 32 32 12 12
20
13
14
0.17093
0.34802
0
12
Table E. Bus Data and Load Flow Results – IEEE 14 Bus system Bus no.
Bus voltage
Generation
Load
Magnitude (P.U.)
Phase angle (deg)
Real power (MW)
Reactive power (MVAR)
Real power (MW)
Reactive power (MVAR)
1
1.060
0.0
232.4
-16.01
0.0
0.0
2
1.045
-4.98
40.0
45.41
21.7
12.7
3
1.010
-12.74
0.0
25.28
94.2
19.0
4
1.019
-10.28
0.0
0.0
47.8
-3.9
5
1.020
-8.76
0.0
0.0
7.6
1.6
6
1.070
-14.22
0.0
13.62
11.2
7.5
7
1.062
-13.34
0.0
0.0
0.0
0.0
8
1.090
-13.34
0.0
18.24
0.0
0.0
9
1.056
-14.92
0.0
0.0
29.5
16.6
10
1.051
-15.08
0.0
0.0
9.0
5.8
11
1.057
-14.78
0.0
0.0
3.5
1.8
12
1.055
-15.07
0.0
0.0
6.1
1.6
13
1.050
-15.15
0.0
0.0
13.5
5.8
14
1.036
-16.02
0.0
0.0
14.9
5.0
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ISSN: 2319-5967 ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 3, Issue 5, September 2014 V. CONCLUSION In simulation study, to simulate the model of UPFC connected to a IEEE 14 bus system MATLAB / SIMULINK software is used. The modeling of unified power flow controller and scrutiny of power system installed with UPFC has been presented, which is skillful for figuring out large power network very faithfully with the UPFC. The research analogous to the fluctuation to the control parameters and fruition / work of UPFC on power quality outcome are carried out. The bump of UPFC on power flow system has been tested fully on standard IEEE 14 Bus system. For standard IEEE 14 bus system the voltage compensation using UPFC system is also being studied. The potency of UPFC to regulate the real and reactive power can be spotted out from simulation results. When UPFC is inaugurated it is found that there is improvement in real and reactive power through the system. REFERENCES [1] Ali Ajami, S.H. Hosseini and G.B. Gharehpetian, “Modeling and Controlling of UPFC for Power System Transient Studies”, ECTI Transactions on Electrical Engineering Electronics, and Communications, vol.- 5, no-2, pp. 29-35, Aug 2007. [2] Amit Shiwalkar and N.D.Ghawghawe, “Power Flow Control through Transmission Line with UPFC to Mitigate Contingency”, International Journal of Advanced Electrical and Electronics Engineering (IJAEEE), vol-1, issue-2, pp. 59-64, 2012. [3] Arup Ratan Bhowmik and Champa Nandi, “Implementation of Unified Power Flow Controller (UPFC) for Power Quality Improvement in IEEE 14-Bus System”, International Journal of Computer Technology Applications, vol.- 2(6), pp. 1889-1996, Nov - Dec 2011. [4] C. Benachaiba, M. L. Doumbia, “Enhancement of Power Quality by Using Power Quality Equipment”, Mediamira Science Publisher, vol.-51, no.2, pp. 104-108, 2010. [5] CH. Chengaiah, R.V.S. Satyanarayana & G.V. Marutheswar, “Study on Effect of UPFC Device in Electrical Transmission System: Power Flow Assessment”, International Journal of Electrical and Electronics Engineering (IJEEE), vol-1, iss-4, pp. 66-70, 2012. [6] K. Manoz Kumar Reddy, “Simulation of Real, Reactive Power and Regulation With UPFC”, International Journal of Scientific and Research Publications, vol:-2, issue 4, pp. 1-4, April 2012. [7] Narain G. Hingorani and Laszlo Gyugyi, “Understanding FACTS: Concepts and Technology of Flexible AC Transmission Systems”, ISBN 0-7803-3455-8, New York: IEEE Press, 2000. [8] Nashiren.F. Mailah and Senan M. Bashi, “Single Phase Unified Power Flow Controller (UPFC): Simulation and Construction”, European Journal of Scientific Research, vol.-30, no. 4, pp.677-684, 2009. [9] Roger C. Dugan, Mark. F. McGranaghan, Surya Santoso and H. Wayne Beaty “Electrical Power Systems Quality”, Third Edition ISBN 978-0-07-176156-7, The McGraw Hill Companies, Inc. [10] T. Nireekshana, Dr. G. Kesava Rao & Dr. S. Siva Naga Raju, “Modeling and Control Design of Unified Power Flow Controller for Various Control Strategies”, International Journal of Engineering Science and Technology, vol.- 2(11), pp. 6293-6307, 2010. [11] S. Muthukrishnan and A. Nirmal Kumar, “Comparison of Simulation and Experimental Results of UPFC used for Power Quality Improvement”, International Journal of Computer and Electrical Engineering, vol.- 2, no. 3, pp. 555-559, June 2010. [12] L. Y. Dong, L. Zhang and M. L. Crow, “A New Control Strategy for the Unified Power Flow Controller”, Power Engineering Society Winter Meeting, 2002. IEEE, vol-1, pp. 562-566, Jan 2002. [13] Bindeshwar Singh, K.S. Verma, Pooja Mishra, Rashi Maheshwari, Utkarsh Srivastava, and Aanchal Baranwal, “Introduction to FACTS Controllers : A Technological Literature Survey”, International Journal of Automation and Power Engineering, vol.1 Issue 9, December 2012. [14] M.E.C. Vidyasagar and S. Ravindra, “FACTS Devices, UPFC with Extended DC Link”, International Conference on Electrical and Electronics Engineering, pp. 148-152, June 2012.
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ISSN: 2319-5967 ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 3, Issue 5, September 2014 [15] S. Muthukrishnan and A. Nirmalkumar, “Comparison and Simulation of Open Loop System and Closed Loop System Based UPFC Used for Power Quality Improvement”, International Journal of Soft Computing and Engineering (IJSCE), vol.- 1, issue 6, pp. 253-258, Jan 2011. [16] Baskar S.,Kumarappan N., and Gnanadass R., “Power Quality Analysis and Mitigation case study using UPFC.”,978-1-4244-7882-8/11©2011 IEEE. [17] N.Hingorani and L.Gyugi, Understanding FACTS-Concepts and technology of Flexible AC Transmission Systems. Piscataway, NJ: IEEE Press/Wiley, 2000. AUTHOR BIOGRAPHY
Ms. Shraddha S. Khonde has completed B.E. in Electrical Engineering from R.C.O.E.M. Nagpur. She is pursuing M.E. in Electrical Power Systems (EPS) from Government College of Engineering, Aurangabad. Prof. S. S. Dhamse has done his B.E. (Electrical) and M.E. (Electrical Power Systems) from Government Institute. Now he is currently working as a Associate Professor in Electrical Engineering Department, Government College of Engineering, Aurangabad. Mrs. Dr. A. G. Thosar has received B.E. (Electrical) and M.E. (Control Systems) from Walchand College of Engineering Sangli. She has completed Ph.D. (Electrical) from IIT, Kharagpur. She is currently working at Government College of Engineering, Aurangabad as professor and Head of Electrical Engineering Department.
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