PERFORMANCE ANALYSIS AND LOCATION IDENTIFICATION OF STATCOM ON IEEE-14 BUS SYSTEM USING POWER FLOW ANALYSIS

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1 ournal of Theoreical and Applied Informaion Technology ATIT & LLS. All righs reserved. PERFORMANCE ANALYSIS AND LOCATION IDENTIFICATION OF ON IEEE-14 BUS SYSTEM USING POWER FLOW ANALYSIS 1 SUNDARARAU.K, 2 NIRMAL KUMAR.A, 3 EEVA.S, 4 NANDHAKUMAR.A 1 Deparmen of Elecrical and Elecronics Engineering, M.Kumarasamy College of Engineering 2 Deparmen of Elecrical and Elecronics Engineering, Karpagam College of Engineering 3,4 Deparmen of Elecrical and Elecronics Engineering, PG Scholar,M.Kumarasamy College of Engineering 1 sunkrr@gmail.com, 2 ankhod@gmail.com, 3 jeevapriya715@gmail.com, 4 nandhakumar3107@gmail.com ABSTRACT FACTS devices open up wide and new opporuniy for he enhancemen of usable capaciy in he power sysem. This paper presens a comprehensive analysis of (STATic synchronous COMpensaor) wih IEEE-14 bus sysem concerning he problem of variable loading and losses. The power flow analysis is performed on a IEEE-14 bus sysem wih and wihou. Due o unequal loading, he mos affeced bus is idenified and he compensaion is done in order o improve he volage for all he buses. The deailed invesigaions are carried ou wih differen loading and he performance of he IEEE-14 bus sysem is examined. The volage regulaion and he reacive power compensaion upo criical poin of volage sabiliy in he sysem is shown hrough proper oupu curves. These invesigaions indicae he need of power flow analysis and locaion of on he proposed sysem. Keywords: Flexible AC Transmission Sysems (Facs), Saic Synchronous Compensaor(), Power Flow Analysis, Ranking Analysis, Volage Regulaion The mahemaical algorihms are used o 1. INTRODUCTION compue he unknown quaniies from he known ones hrough a process of successive rial and error mehods and consequenly produce a resul. The iniial values of he sysem are assumed and he program compues he successive quaniies. The load flow soluion is needed o deermine he overloading of paricular elemens in he sysem. I is also used o make sure ha he generaors run a he ideal operaing poin, which ensures ha he demand will be me wihou overloading he faciliies and eiher mainains hem wihou compromising he securiy of he sysem or he demand. The objecives of any load flow analysis is o produce he following informaion The power flow sudies are very common in power sysem analysis. flow allows us o know he presen sae of a sysem, given previous known parameers and values. The power ha is flowing hrough he ransmission line and is generaed by he generaors, he power ha is being consumed by he loads, he losses occurring during he ransfer of power from source o load and so on all are ieraively decided by he load flow soluion or also known as power flow soluion. In any sysem, he mos imporan quaniy is known as he volage a differen poins hroughou he sysem. Flexible AC ransmission sysem (FACTS) conrollers are able o change he power sysem parameers in an effecive way. In FACTS conroller, he is used for enhancing he performance of power sysem. The volage and angle sabiliy are improved by he concern of. Volage magniude and phase angle a each bus. Real and reacive power flowing in each elemen. Reacive power loading on each generaor. 2.1 Power Flow Equaions of n Sysem wih 2. NEED OF COMPUTATIONAL ALGORITHM The is conneced in parallel wih bus S in he power sysem. The bus S is heavily affeced by volage regulaion. The 365

2 ournal of Theoreical and Applied Informaion Technology ATIT & LLS. All righs reserved. conrollable volage source of is denoed as V in series wih Z impedance. The power flow equaions of he sysem wih conneced o bus S are he same as power flow equaions of he sysem wihou for all buses excep conneced bus S. The following equaions are power flow equaions for bus S. Pi δi Q V i i Pv V F δ where conrol variable for jacobian marix, FV s. (6) 3. IEEE 14 BUS SYSTEM Figure 1: connecion in a bus n Ps P + Vs Ysj Vj cos( δs δj θsj) j 1 n Qs Q + Vs Ysj Vj cos( δs δj θsj) j 1 (1) (2) The summaion erms of he injeced acive and reacive power for he sysem, 2 + s s δs δ θ P G V V Y V cos( ) 2 s s δs δ θ (3) Q B V V Y V sin( ) (4) Where V, δ, Y and θ are noed in figure 1 and oher variables were given in equaions (3) and (4). One more equaion is needed o solve he power flow problem. This equaion is needed o find he power consumed by he source V. The power mus be zero in seady sae condiion. * 2 v s s P Real VI GV + V Y Vcos( δ δ θ ) 0 (5) 2.2 acobian Equaion wih As per he above equaions, he new power flow problem wih has o be solved. The linearized acobian equaion is exended and modified as per new acobian equaion below. IEEE 14 bus sysem is used o es he power flow analysis wihou and wih. The IEEE14 bus es sysem is shown in figure 2. Here, he is conneced randomly a differen buses. The volage of all buses is heavily affeced for he increasing load. The is randomly conneced and power flow losses for various buses are calculaed o improve he volage profile and also compensae he reacive power of whole sysem. Using he Newon Raphson mehod, he following analysis are made, i) To find base load losses of all buses and also oal losses of IEEE 14 bus sysem. ii) To find load losses of all buses and also oal losses for differen load variaion wihou iii) To find load losses of all buses and also oal losses for differen load variaion wih Iniially he 14 bus sysem is esed wihou. The real and reacive power flow is analysed by using he Newon Raphson mehod. Then all he buses are analysed he same wih he. This Power Flow approach for volage sabiliy analysis of unbalanced power sysems has been proposed. The approach can be aken ino accoun for he unbalances of boh nework and load in 14 bus sysem [1]. Now he loads of he oher buses are considered and overall power generaion is varied wih increasing percenage from 40% o 100%. IEEE 14 bus sysem is now used o es he load flow analysis wihou and wih. For his analysis, he is conneced randomly in differen buses here by verifying he real and reacive power variaion. 366

3 ournal of Theoreical and Applied Informaion Technology ATIT & LLS. All righs reserved. funcion, is o minimize he invesmen coss for devices and he generaion coss.[5] 5.1 Raing of Figure 2: IEEE 14 Tes Sysem Iniially he sysem is invesigaed during seady sae.a comparaive analysis is made wih differen loading condiions. The load is increased keeping 40% of he load a he sar. 4. STABILITY OF POWER SYSTEM Modern elecric power sysem is a complex nework of synchronous generaors, ransmission lines and loads. Elecric uiliies firs aced as isolaed sysems, and hen gradually neighboring uiliies began o join forming large inerconneced neworks. This enabled he uiliies o draw on each oher s generaion reserves during he ime of need. Three phase faul or sudden load swiching which creaes ransiens. This makes he sysem o be unsable which is very worse. A good power sysem should possess he abiliy o regain is normal operaing condiion afer a disurbance. Since he abiliy o supply uninerruped elecriciy deermines he qualiy of elecric power supplied o he load, sabiliy is regarded as one of he imporan opics of power sysem research[2, 3, 4]. 5. OPTIMAL ALLOCATION OF devices can be used o conrol power flows in large power sysem neworks. ypes and locaions should be reasonably chosen according o heir conribuion o he general objecive of power sysem economic generaion and dispach. In his research, using he MATLAB m-file program, he locaions of he devices are opimized simulaneously along wih he raed values. The objecive cos The naure and he ype of fauls ha he sysem need o overcome decides he size of he. Alhough he final raing of he is deermined based on sysem economics, he raing chosen mus be aleas adequae for he sysem o be sable afer a faul or emporary sysem disurbances. The raings are based on many parameers which are mosly governed by he amoun of reacive power he sysem needs o recover and ride hrough sysem fauls on he power sysem and o reduce he ineracion of oher sysem causing disurbances. This causes ou of synchronism wih he grid. The naure and he ype of fauls ha he sysem need o overcome decides he size of he. For example, a hree phase faul of low impedance requires a very high raing.a high impedance shor circui faul needs a lower raing device[5]. This suppor is needed o sabilize he sysem afer a disurbance. The capabiliy of he is also decided based on he converer curren raings and he size of he capacior. The devices in a volage source converer are clamped agains over-volages across he DC link capacior bank o minimize losses and no have o wihsand large spikes in reverse overvolage [5]. 5.2 Effecive Locaion of Simulaion resuls show ha provides effecive volage suppor a he bus o which i is conneced o. The is placed as close as possible o he load bus for various reasons. There are wo imporan reason for choosing he locaion of. i)the locaion of he reacive power suppor should be as close as possible o he poin a which he suppor is needed. ii) The locaion of he a he load bus is more appropriae. The locaion of he is based on quaniaive benefis evaluaion. The main benefis of using a in he sysem are reduced losses and increased maximum ransfer capabiliy. [6] Placing a a any load bus compensaes he reacive power flow hrough he lines, which auomaically reduces line curren and also he 367

4 ournal of Theoreical and Applied Informaion Technology ATIT & LLS. All righs reserved. I 2 R losses. The locaion of is generally chosen o be he locaion in he sysem which needs reacive power. Shipping of reacive power a low volages in a sysem running close o is sabiliy limi is no very efficien.[6] Also, he ransmission line power facor limiing facors decides he oal amoun of reacive power ransfer available in he sysem. This proves ha sources and compensaion devices are o be kep as close as possible o he load. reacive power compensaion and losses for he load variaion are calculaed. 6. REACTIVE POWER SUPPORT FROM COMPENSATING DEVICE The amoun of reacive power supplied by any compensaing device depends on he volage drop a he bus and is capabiliies. For example, a can supply is maximum raed compensaing curren even a lower volages. The reacive power ha can be supplied, bu usually hey have some exra capabiliy called he ransien capabiliy which is available o he sysem for a shor period of ime. The reacive power supplied is also dependen on he immediae reacive power sources in he sysem [6]. Figure 3: Real Power variaion wihou and wih 7. SIMULATION AND TEST RESULTS 7.1 Real and Reacive Power Variaion The following resuls are shown o compensae he real power and reacive power losses for he load variaion. Here due o he reacive power variaion, he volage of all buses are improved wih raed value by connecion of. The change in real and reacive power for differen load variaion is shown in Figure 3 and Figure 4 respecively. The posiion of is varied and adjused slighly for he real and Figure 4: Reacive Power variaion wihou and wih Table 1: Ranking Lis for Volage Variaion Losses wihou Losses wih MW MVar MW MVar Base load % % % % % % %

5 ournal of Theoreical and Applied Informaion Technology ATIT & LLS. All righs reserved. Table 2: Ranking Lis for Reacive Power Variaion Rank % 1 50% 1 60% 1 70% 1 80% 1 90% 1 100% 1 Rank 40% % 1 60% 1 70% 1 80% 1 90% 1 100% 1 369

6 ournal of Theoreical and Applied Informaion Technology ATIT & LLS. All righs reserved. The affeced buses are ranked in 1, and buses respecively by volage variaion. Here rank lis is only analysed and verified for finding he real and reacive power variaion. The variaion in power wih increasing loads is lised wih and wihou in Table 3. The ransmission losses are reduced and reacive power is compensaed wih he help of. The ranking is prepared for reacive power compensaion in various loads by. The ranking lis is given in Table 2.This ranking analysis is very useful in analyzing he effecive locaion of. 7.2 Volage Curve for Variaion By connecion of, he volage of all buses are improved and is found o be above 1 p.u. The volage regulaion performance of he is clearly shown in figure 5. Here due o he reacive power variaion, he volage of all buses are improved wih raed value by connecion of. From he graph, i is inferred ha he sysem performance can be improved o a greaer exen wih he connecion of. Figure 5: Volage Curve for Variaion Table 3: Real and Reacive Power Losses Wihou he connecion of,he sysem performance is no in a appreciable level hence he losses are more. By connecing he in a effecive locaion he real and reacive power losses are reduced. CONCLUSION The power flow analysis wihou and wih is performed on IEEE-14 bus sysem. The IEEE-14 bus sysem and are modeled using MATLAB m-file. By injecing he addiional volage and power angle, he ransmission losses are analyzed for various buses. The is conneced in differen buses for differen loads. The ransmission losses are calculaed and compared wih oher buses which is conneced wih. The locaion of on IEEE-14 bus sysem are idenified by ranking analysis for volage variaion and reacive power compensaion. The gives beer reacive power compensaion and volage regulaion in,, and buses respecively. APPENDIX: As per he above acobian marix, he elemens are , (Diagonal elemens) δ i δ j 12 Vi Vj 14 V, (Diagonal elemens) δ i δ j (Diagonal elemens) Vi Vj 24 V P P V v v Pv Pv 34 Vi F V i where conrol variable for jacobian marix, FV s. 370

7 ournal of Theoreical and Applied Informaion Technology ATIT & LLS. All righs reserved. REFERENCES: [1]. G.W.Sagg and A.H.EL-abaid, Compuer mehods in power sysems (New York hills, 1968). [2]. N.G. Hingorani, L. Gyugyi, Undersanding FACTS Conceps and echnology of Flexible AC Transmission Sysems, IEEE Press, [3]. P.M. Anderson and A.A.Fouad, Power sysem conrol and sabiliy, Iowa sae universiy press, [4]. L.. Cai and I. Erlich, " Simulaneous Coordinaed Tuning of PSS and FACTS Damping Conrollers in Large Power Sysems, " IEEE Transacions on Power Sysems. [5]. Xiao-Ping Zhang,, Ping u Coninuaion Three-Phase Power Flow: A Tool for Volage Sabiliy Analysis of Unbalanced Three-Phase Power Sysems IEEE ransacions on power sysems. [6]. H. Okamoo, A. Kuria, Y.Sekine, A mehod for idenificaion of effecive locaions of variable impedence apparaus on enhancemen of seady-sae sabiliy in large scale power sysems, IEEETransacions on Power Sysems. [7]. Gabriela Hug-Glanzmann, G oran Andersson,Zurich, Swizerland., Coordinaed Conrol of FACTS Devices in Power Sysems for Securiy Enhancemen irep Symposium - Bulk Power Sysem Dynamics and Conrol. [8]. Sidharha Panda and Narayana Prasad Padhy, Power Sysem wih PSS and FACTS Conroller: Modelling, Simulaion and Simulaneous Tuning Employing Geneic Algorihm, inernaional journal of elecrical, compuer, and sysems engineering. [9]. P.K. Padiyar, Power sysem sabiliy and conrol EPRI Power sysem series [10]. Y. H. Song, A. T. ohns. Flexible AC Transmission Sysems (FACTS), IEE Press, London,