Research Journal of Recent Sciences _________________________________________________ ISSN 2277-2502 Vol. 4(7), 100-104, July (2015) Res.J.Recent Sci. International Science Congress Association 100 Optimal Location and Capacity of UPQC for improvement of Voltage profile and Reducing loss in distribution Network by Data Sharing AlgorithmGhobadi M.R.*, Moradi A., Havasi H. and Habibi R.4 1,2,4Department of Electrical Engineering, Science and Research Branch, Islamic Azad University, Kermanshah, IRAN Department of Electronic and Computer Engineering, Payame Noor University, 19395 3697, Tehran, IRAN Available online at: www.isca.in , www.isca.me Received 20th January 2014, revised 1st April 2014, accepted 17th September 2014Abstract Voltage profile improvement and loss reduction are two goals that should be considered for providing better service for consumers in the distribution network. Several methods for this goal have been studied before that including capacitor and Custom Power Devices (CPD) installation. However, since these devices are so expensive, we must use them in minimum cost. So, for installation of these devices, the optimal location and capacity of them should be found. The study of this important issue is done in this paper, and we used Unified Power Quality Conditioner (UPQC) for steady state improvement of voltage profile and reduction of power loss. Our method is tested in 33-bus and 69-bus test systems, by using Data Sharing Algorithm (DSA). Keywords: UPQC, Data Sharing Algorithm, Optimal Location and Capacity, Loss reduction, Voltage profile improvement. IntroductionVoltage profile improvement and loss reduction are two goals that should be considered for providing better service for consumers in the distribution network. Generation and transmission of power to demand nodes is one of the most important issues in power system. There are several devices such as capacitors and FACTS devices that can maintain the voltage of buses in acceptable limits. Unfortunately, the reaction of capacitor for improvement of voltage stability is slow. So, in some conditions like voltage sag, the required reactive power for increasing voltage cannot be provided by the capacitors. One other disadvantage of the capacitor is that it does not have a continuous control on its output. In contrast, the Custom Power Devices (CPD) like Unified Power Quality Conditioner (UPQC) has injection/absorption ability of the reactive power to/from the distribution network. UPQC has not other disadvantages of capacitors. Therefore, UPQC can effectively support the network demands. The FACTS equipments in distribution network are named CPD. They have structures like FACTS, but their control methods have been changed, in order to support distribution network needs. Several researchers1-10 are studied about improvement of power quality with CPD. The D-STATCOM is a CPD device that is in parallel with the network. It usually uses for some power quality goals like1-2. DVR is another from them. This device places in series in distribution network. The DVR usually places in network for voltage dip and unbalance elimination3-5. The perfect member of this family is UPQC that has two parts, series and parallel. This device is the integration of DVR and D-STATCOM. UPQC can respond dynamically to all of power quality needs of the network like voltage unbalance, voltage dip, voltage flicker and harmonic6-10. Tooraji and Abdolamir improved power quality with Unified Power Quality Controller11. Our goal in this paper is finding of the optimal capacity and location of UPQC for voltage profile improvement and loss reduction. A method has been proposed by Hosseini et al 12 for gaining this purpose. This reference has some deficiencies which are mentioned below: First, for determination of optimal UPQC location, in this paper UPQC has placed in all buses, then the location that has the most positive influence on voltage profile, is chosen as its optimal location. Obviously, this method is not effective in large scale networks. Second, the capacity of UPQC parallel section is considered constant, 2 Mega Var. This allocation is in contrast with optimal capacity determination of UPQC. For completion of our research the optimal location and capacity of UPQC have been obtained by Data Sharing Algorithm (DSA) for reducing loss and steady state improvement of voltage profile in the distribution network13. Research Journal of Recent Sciences _____________________________________________________________ ISSN 2277-2502Vol. 4(7), 100-104, July (2015) Res.J.Recent Sci. International Science Congress Association 101 Problem Formulation The model of UPQC in steady state: The 2-bus network is shown in figure-1. The phasor diagram of this network is shown in figure 2, too. The voltages of buses of each network generally are close to one. In this paper our goal is to improve buses voltages to one by UPQC. The buses voltages in 2-bus network have relationship that is as follow:  \n \r (1) Figure-1 The 2-bus distribution network Figure-2 The phasor diagram of 2-bus distribution network In this paper we suppose that the reactive power only exchange between series and parallel parts of UPQC with network. Our goal from installation of UPQC is that the  bus voltage reaches to 1.  and  buses voltages after UPQC installations have shown in figure-3. Because, there is no active power exchange,  is perpendicular to  , and  !" to#$!%. The figure 3 has resulted to equation-2. &'()*+ \n \r\n \r,-.&/0)*+\r 3\r,'4',(2) The $!%567 and are the  bus voltage and line current after installation of UPQC, respectively. Other figures of UPQC are proposed by Hosseini et al. The objective function and optimization method: The problem of optimal capacity and location of UPQC for improvement of voltage profile and reducing loss in distribution network has been solved by Data Sharing Algorithm (DSA) in this paper. It has been tried to compensate the buses voltage and reducing loss by minimum capacity of UPQC. The objective functions are defined according to equations-3 and 4. 9:;####= &#x-4.8;΃9?##@A##9B)###=\n &#x-4.8;΃9?# (3) 9B)####CDE+*F#GEHHJLM (4) RUVMN in equation-3, indicates the Rate of Under Voltage Mitigated Nodes. In other words, it shows the percentage of buses that are outside of the voltage allowed region and entered into the allowed region after UPQC installation. Equation-4 is power loss of the network. b is the number of branches. Simulation Results In order to survey our method, the 33-bus distribution network is chosen (figure 4). The network information is proposed by Hosseini et al. Figure-3 The diagram of two buses distribution network after the installation of UPQC Research Journal of Recent Sciences _____________________________________________________________ ISSN 2277-2502Vol. 4(7), 100-104, July (2015) Res.J.Recent Sci. International Science Congress Association 102 Figure-4 The 33-bus test networkResults of load flow are in table 1 and this results show that before UPQC installation, %63.63 of buses are not in acceptable region. The acceptable voltage limit is considered#NOP. So, if after UPQC installation, RUVMN reaches to %63.63, it means that all buses are in the acceptable region. The flowchart of our proposed method is shown in figure-5. In figure-5, first lines and buses information are entered, and then before UPQC installation the load flow program runs. The numbers of buses outside the allowed region are 21 which are 63.63% of all buses. Second, the DSA parameters are entered and the initial values of population members are set. These members determine location and capacity of the parallel port of UPQC. Also, the reactive power capacity of series part of UPQC is obtained after running the load flow program. The steps for obtaining this power are too long and we do not write its related equations. These equations completely have been proposed by Hosseini et al. In the next step, by members encoding and running the load flow program, objective functions for all members are computed. Then a new population is made by DSA operators. This process is continued until the final answer is achieved. The results of load flow program before UPQC installation are in table-1. As it can be seen, 21 buses from 33 buses are not in the acceptable region. After running of DSA the output of program has been illustrated in figure-6. The horizontal axis shows the negative percentage of buses that placed in the allowed region after the installation of UPQC, while the vertical axis demonstrates the power loss of the network. The characteristics of points in figure 6 have been listed in table-2. So our final results are in table-2. Now we implement our method in 69-bus test network that is proposed by Hosseini et al. The results of the simulation are shown in figure-7 and table-3. What we pursued in this paper was the optimal location and capacity of UPQC for steady state voltage profile improvement and loss reduction in networks. About the figures 6 and 7, we can say that all of the points in these figures are optimal and the operator of the networks can choose one of the points base on his desire. Figure-5 The flowchart of proposed method Start Entering the information of lines and buses of distribution network Running of load flow program and determining the value of buses voltage before installation of UPQC The initialization of Data Sharing algorithm parameters and producing the initial population. Determination of fitness functions for each population member The determination of capacity and location of UPQC for each population member Running the load flow program and determination of new voltages Population encoding No Yes No Last Member ? Do DSA operators Producing new generation End Print results Is the processing enough? Yes Research Journal of Recent Sciences _____________________________________________________________ ISSN 2277-2502Vol. 4(7), 100-104, July (2015) Res.J.Recent Sci. International Science Congress Association 103 Table-1 The characteristics of buses before installation of UPQCBus number Voltage value Voltage phase Bus number Voltage value Voltage phase Bus number Voltage value Voltage phase 1 0 11 0.9269 -0.1772 22 0.9794 0.0651 0.9970 0.0145 12 0.9208 -0.2685 23 0.9727 -0.0236 0.9829 0.0961 13 0.9185 -0.3472 24 0.9694 -0.0673 0.9755 0.1617 14 0.9171 -0.3849 25 0.9477 0.1734 0.9681 0.2283 15 0.9157 -0.4081 26 0.9452 0.2296 0.9497 0.1339 16 0.9137 -0.4854 27 0.9337 0.3112 0.9462 -0.0964 17 0.9131 -0.4950 28 0.9255 0.3891 0.9413 -0.0603 18 0.9965 0.0037 29 0.9219 0.4944 0.9351 -0.1334 19 0.9929 -0.0633 30 0.9178 0.4100 0.9292 -0.1959 20 0.9922 -0.0827 31 0.9168 0.3869 10 0.9284 -0.1887 21 0.9916 -0.1030 32 0.9166 0.3792 Figure-6 The program output of DSA for 33-bus test networkTable-2 The characteristics of figure 6 points 33.333336.363663.6364F1 (%) 1.35011.35081.4339F2 (pu) 2929Optimal location of UPQC 132413711693The exchanged reactive power through UPQC (Kvar) Conclusion The problem of optimal capacity and location of UPQC for improvement of power quality in distribution network has been investigated in this paper by the DSA. The results of the simulation showed that UPQC can solve the voltage profile and Table-3 The characteristics of figure 7 points -2.898-13.04-20.29-26.08F1 (%) 1.85521.97682.13242.3552F2 (pu) 45383613Optimal location of UPQC 1552158516241845The exchanged reactive power through UPQC (Kvar) loss reduction problems by exchanging the optimal amount of reactive power. According to this paper, this optimization method can be used for finding the optimal location and capacity of UPQC for industrial networks that struggle with power quality problems. Research Journal of Recent Sciences _____________________________________________________________ ISSN 2277-2502Vol. 4(7), 100-104, July (2015) Res.J.Recent Sci. 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