Volume 3, Special Issue 3, March 2014

Transcription

1 ISSN (Onlne) : ISSN (Prnt) : Internatonal Journal of Innovatve Research n Scence, Engneerng and Technology Volume 3, Specal Issue 3, March Internatonal Conference on Innovatons n Engneerng and Technology (ICIET 14) On 1 st & nd March Organzed by K.L.N. College of Engneerng, Madura, Taml Nadu, Inda Optmal Szng Of Dstrbuted eneraton For Voltage Profle Improvement Consderng Maxmum Loadablty Lmt Dr.K.nanambal #1, S.Surya* 1 Professor, Department of Electrcal and Electroncs Engneerng, K.L.N College of Engneerng, Svaganga, Inda. P..Scholar (M.E.Power System Engneerng, Department of Electrcal and Electroncs Engneerng, K.L.N College of Engneerng, Svaganga, Inda. ABSTRACT - Nowadays power demand s the maor problem n the electrcty market. Dstrbuted eneraton The penetraton and vablty of at a () s becomng more mportant n the power system partcular locaton s nfluenced by techncal as well as because of ts hgh effcency. Ths paper s concerned economc factors. The techncal merts of wth the Dfferental Evoluton Algorthm for the optmal mplementaton nclude voltage support, energy loss szng of Dstrbuted eneraton. The obectve s reducton, and release of system capacty and mprove mnmzaton of cost and mzaton of the utlty system relablty[3]. Two methodologes for loadablty value. The mprovement of voltage profle s optmal placement of dstrbuted generaton () n an also consdered. IEEE-14 bus system and 34 bus Radal optmal power flow based wholesale electrcty market Dstrbuton System are consdered to test the were presented n [3]. The mnmzaton of cost and loss effectveness of the DE for optmal szng of wth wth the mum potental beneft was suggested n [4]. mzng the loadablty and mnmzng the cost. The formulaton of three phase optmal power flow wth the control varables (actual actve load demand and KEYWORDS: - Dstrbuted eneraton (), Economc reactve power outputs of mcro generators) was Dspatch (ED), Optmal Power Flow (OPF), Dfferental presented n [5].The analytcal methods to determne the Evoluton (DE), Maxmum Loadablty Lmt. optmal locaton of n radal dstrbuton networks for I.INTRODUCTION loss mnmzaton n the power system s proposed n [6]. Dstrbuted eneraton s a small power Partcle Swarm Optmzaton algorthm (PSO) for the generatng unt that s usually connected to the optmal placement and szng of unts n order to dstrbuton system. It s also known as Embedded reduce network congeston was presented n [7].One of eneraton (E) or Dspersed eneraton (). the most powerful evolutonary algorthm s Dfferental Dstrbuted eneraton () whch conssts of dstrbuted Evoluton (DE) because of ts excellent convergence resources, can be defned as electrc Power generaton characterstcs and a few control parameters. The wthn dstrbuton networks or on the consumer sde of computatonal algorthm of DE s smple to understand the network [1]. mpacts on dstrbuton system and mplement. Only a few parameters are requred to be depends on several factors such as locaton, capacty set by the users [9-11]. of and the mode of operaton wth network []. The mum loadablty lmt s the margn s an emergng approach for provdng electrc power between the operatng pont of the system and the to the power system. mum loadng pont that can be formulated as an optmzaton problem. Ths paper concentrates the voltage profle mprovement by placng the wth the constrant of mzng the loadablty and mnmzng the cost by usng Dfferental Evoluton Algorthm. Copyrght to IJIRSET M.R. Thansekhar and N. Bala (Eds.): ICIET 14

2 Optmal Szng of Dstrbuted eneraton for Voltage Profle Improvement Consderng Maxmum Loadablty Lmt III.PROBLEM FORMULATION II. OVERVIEW OF THE PROPOSED IDEA Fg.1. represents the overvew of the paper. Optmal locaton of s determned by usng the Dfferental Evoluton algorthm. After the locaton of by changng the penetraton level the mnmzaton of cost and the mzaton of the loadablty s done by usng the DE. Start Read bus data and lne data for IEEE 14 bus system, 34 bus radal dstrbuton system and Cost coeffcents for Dstrbuted eneraton Load Flow Analyss for the proposed system usng NR method Changng the penetraton level of wth the constrants of mzng the loadablty usng DE No Run load flow analyss usng NR method If Condton s Satsfed? Yes Output Improvement of Voltage profle, lne loss reducton, cost reducton etc. Obectve Functon The obectve functon states that the mnmzaton of the cost wth the mzaton of the loadablty. The mnmzaton of the cost s expressed n (1): NL Mn K1 * C( P ) (1) 1 The mzaton of the loadablty expressed n the (): NL Max K *( PD) () 1 NL=Total Number of Loads C(P ) P b a P c a, b, c are the cost coeffcents of. K 1 and K are the Penalty Factors. Subected to the Constrants Change n power N P = V V Y cos( ) 1 The change n real power s obtaned by the total real power generaton mnus total load real power demand mnus specfed th bus real power. ΔP=P g - P d - P (3) Where P d = P do + λ P g = P go + P dg N Q = V V Y Sn( ) 1 The change n reactve power s obtaned by the total reactve power generaton mnus total load reactve power demand mnus specfed th bus reactve power. ΔQ=Q g - Q d + Q (4) Inequalty Constrants Real power generaton lmts The real power at generator bus s mantaned wth ts acceptable lmt s expressed as P mn P P (5) =1, N P = mum real power level at bus P mn = mnmum real power level at bus N = Number of enerators s Fg.1.Flowchart for Proposed work Reactve power generaton lmts: The reactve power at generator bus s mantaned wth ts acceptable lmt s expressed as mn Q Q Q (6) Copyrght to IJIRSET M.R. Thansekhar and N. Bala (Eds.): ICIET 14

3 Optmal Szng of Dstrbuted eneraton for Voltage Profle Improvement Consderng Maxmum Loadablty Lmt =1, N Q = mum reactve power level at bus Q mn = mnmum reactve power level at bus N = Number of enerators Lne flow lmt The lne flow lmt specfes the mum allowable complex power transfer n the transmsson lne. S S S S S = the complex power transfer between the bus and. S = the complex power transfer between the bus and. S = the mum complex power transfer capacty of lne to. S = Maxmum complex power transfer capacty of lne to. voltage lmt: Voltage level at a load bus s mantaned wth ts acceptable lmt s expressed as: V mn V V (7) = 1,,.NL V = mum voltage level of bus. V mn = mnmum voltage level of bus. IV. OVERVIEW OF DIFFERENTIAL EVOLUTION As a relatvely new member of EAs, DE s less known outsde meta heurstc optmzaton area. Smlar to other EAs, DE reles lkewse on the ntal populaton generaton, mutaton, recombnaton and selecton to probe search space through teratve progress untl the termnate crtera are met. [1] Man operators for DE: The performance of DE s manly dependent on three operators, mutaton, recombnaton and selecton. Detaled dscusson of them s presented accordngly n the sequel. Mutaton: The functon of mutaton n DE s to mantan the dversty of populaton as well as provde necessary nformaton to steer the optmzaton. A typcal DE mutaton formulaton s ' 1 x x f ( x x ) (8) 1 Where represents the th generaton, r1 r I, and r1, r are randomly selected ntegers wthn the populaton sze NP, r1, r {1,,.,N P }, If x to replace x, then x ' 1 x r3 r1 f.( x x ) Clearly (5) s a lnear combnaton of two vectors and the resultng mutaton becomes an arthmetc crossover process. Recombnaton: Recombnaton or crossover s the man operator for As but only a complementary process for DE. The basc recombnaton process s a dscrete recombnaton, whch employs a constant C R [0, 1] to determnate f the newly generaton ndvdual s r r (9) r to be recombned. Alternatvely, the arthmetc crossover formula of (5) can be used to acheve the rotatonal nvarance whch s otherwse dffcult to be acheved wth the dscrete recombnaton. The resultng expresson of the mutaton and crossover processes are gven n (10) as a combnaton of (8) & (9) ' 1 x x f.( xr x ) F.( xr1 xr ) (10) Where the randomly generated ntegers r1 r r3, F s the mutaton constant and f controls the crossover constant. f [0, 1] and remans constant throughout the evoluton process.the values of F and f are commonly determned on the case to case bass. Selecton: DE adopts a very smple selecton ' 1 operator. A newly generated chld ndvdual x s compared wth parent Copyrght to IJIRSET f ( x ) f ( x 1 M.R. Thansekhar and N. Bala (Eds.): ICIET 14 x and replaces t f ). It ensures that the cost of the ndvdual and the overall populaton wll not ncrease throughout the search process. V.RESULTS AND DISCUSSION The proposed DE algorthm s appled to determne the optmal locaton and szng of wth the constrant of mzng the loadablty have been conducted under MATLAB 1 envronment. The test system used to demonstrate the paper work s, IEEE 14 bus system. 34 bus Radal Dstrbuton System. A.IEEE 14 BUS SYSTEM The standard IEEE-14 bus system conssts of 6 generator bus, 9 load buses and 0 transmsson lnes. The generator buses are 1,, 3, 6 and 8 wth the slack bus connected to node 1. The other nodes are connected to all other nodes. The optmal locaton and szng of wll takes place at all load buses. The voltage profle mprovement for the IEEE 14 bus system wth and wthout usng Dfferental Evoluton (DE) s dscussed n Table 1. Optmal Szng of wll takes place on load buses and determne the best optmal locaton and sze wth the constrant of mum loadablty and mnmzng Cost that wll be dscussed n Table.

4 Optmal Szng of Dstrbuted eneraton for Voltage Profle Improvement Consderng Maxmum Loadablty Lmt Table 1. Comparson of Voltage Profle wthout and wth usng DE Wthout Dstrbuted eneraton Voltage Phase Magntude angle n n p.u deg Wth Dstrbuted eneraton Voltage Phase Magntude angle n n p.u deg The voltage profle mprovement for the 34 bus system wth and wthout by usng Dfferental Evoluton (DE) s dscussed n Table 3. Optmal Szng of wll takes place on mnmum voltage buses and determne the best optmal locaton and sze wth the constrant of mum loadablty and mnmzng Cost that wll be dscussed n Table 4. Fg.3. Convergence Characterstcs for 34 bus Radal Dstrbuton System. Table. Optmal szng of Optmal sze n MW Cost n $/MWh Maxmum Loadablty n p.u Table 3. Comparson of Voltage Profle wthout and wth usng DE Optmal sze n MW Cost n $/MWh Maxmum Loadablty n p.u Fg.. Convergence Characterstcs for the IEEE 14 bus System B.34 bus Radal Dstrbuton System The second test case for the proposed method s a 34 bus radal dstrbuton system.ths system conssts of man feeder and four laterals. The lne and load data are taken from reference. Copyrght to IJIRSET M.R. Thansekhar and N. Bala (Eds.): ICIET 14

5 Optmal Szng of Dstrbuted eneraton for Voltage Profle Improvement Consderng Maxmum Loadablty Lmt Table 4. Optmal szng of Wthout Dstrbuted eneraton Voltage Magntud e n p.u Phase angle n radan Wth Dstrbuted eneraton Voltage Magntud e n p.u Phase angle n radan VI CONCLUSION Ths paper presented a method for optmal szng of to mprove mum allowable load n the dstrbuton system. Dfferental Evoluton algorthm has been proposed for the optmal szng of. IEEE 14 bus system and 34 bus radal dstrbuton system are consdered to test the effectveness of DE. Lst of Symbols N : Number of generators NL : Number of Loads V mn V : Maxmum voltage level at node : Mnmum voltage level at node S : Complex power transfer between the bus and. S mn S : Maxmum complex power transfer capacty of the lne - : Mnmum complex power transfer capacty of the lne - P : Actve power generated through generator. P : Demand power of customer D P : Dstrbuted eneraton power b c :, Cost of coeffcents for a, Dstrbuted eneraton P : The calculated real power for the th bus. : Maxmum real power P generaton at generator. P : Mnmum real power m n generaton at generator. Copyrght to IJIRSET M.R. Thansekhar and N. Bala (Eds.): ICIET 14

6 Optmal Szng of Dstrbuted eneraton for Voltage Profle Improvement Consderng Maxmum Loadablty Lmt REFERENCE [1] J.A. Pecas Lopes, N.Hatzagyrou, J.Mutale, Integratng dstrbuted generaton nto electrc power systems: A revew of drvers, challenges and opportuntes, Electrc Power System Research 77 (007), pp [] K.Balamurugan, Dpt Srnvasan, Thomas Rendl, Impact of Dstrbuted eneraton on Power Dstrbuton Systems, Energy Proceda 5(01) [3] Durga autam and Nadaraah Mthulananthan, Optmal placement n deregulated electrcty market, Electrc Power Systems Research 77 (007), pp [4] Sudpta hosh, S.P.hoshal, and Saradndu hosh, Optmal szng and placement of dstrbuted generaton n a network system, Electrcal Power and Energy Systems 3(010) [5] Sergo Bruno, Slva Lamonaca, useppe Rotondo, Ugo Stecch, and Massmo La Scala, Unbalanced Three-Phase Optmal Power Flow for Smart rds, IEEE Transactons on Industral Electroncs, vol.58, 10, October 011. [6] N.Acharya, An Analytcal Approach for Allocaton n Prmary Dstrbuton Network, Elsever Journal of Electrcal Power and Energy Systems, vol.8, pp , 006. [7] Seon-Ju Ahn, Soon-Ryul Nam, Joon-Ho Cho and Seung-II Moon, Power Schedulng of Dstrbuted enerators for Economc and Stable Operaton of a Mcrogrd, IEEE Transactons on Smart rd, vol. 4, 1, March 013. [8] Monca Alonso, Hortensa Amars and Carlos Alvarez-Ortega, Integraton of renewable energy sources n smart grd by means of evolutonary optmzaton algorthms, Expert Systems wth Applcatons 39(01), pp [9] Chung-Fu Chang, J-Jen Wong, J-Pyng Chou and Chng-Tzong Su, Robulst searchng hybrd dfferental evoluton method for optmal reactve power plannng n large scale dstrbuton systems, Electrc Power Systems Research, Vol 77, pp , Aprl 007. [10] Ca, H.R. Chung, C.Y.Wong, K.P. Applcaton of Dfferental Evoluton Algorthm for Transent Stablty Constraned Optmal Power Flow, IEEE Transactons on Power System Vol 3, pp , May 008. [11] Xaohu Yuan, Anun Su, Hao Ne, Yanbn Yuan and Lang Wang, Applcaton of enhanced dscrete dfferental evoluton approach to unt commtment problem, Energy Converson and Management, Vol 50, Issue 9, pp , Sept 009. [1] uang Ya Yang, Zhao Yang Dong and Kt Po Wong, A Modfed Dfferental Evoluton Algorthm wth Ftness sharng for Power System Plannng, IEEE Trans. on Power Systems, Vol 3, pp May 008 Copyrght to IJIRSET M.R. Thansekhar and N. Bala (Eds.): ICIET 14