CONTRIBUTIONN OF GENERATORS IN POWER SYSTEM NETWORK USING POWER FLOW TRACING METHOD

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1 Iteratoal Joural of Mechacal Egeerg ad Techology (IJMET) Volume 8, Issue 8, August 07, pp. 7 6, Artcle ID: IJMET_08_08_04 Avalable ole at me.com/ijmet/ssues.asp?jtype=ijmet&vtype=8&i IType=8 ISSN Prt: ad ISSN Ole: IAEME Publcato Scopus Idexed CONTRIBUTIONN OF GENERATORS IN POWER SYSTEM NETWORK USING POWER FLOW TRACING METHOD Dr.M.Veataswara Rao ad Balla Moua Departmet of Electrcal ad Electrocs Egeerg, GMR Isttute of Techology, Raam, AP. Ida. ABSTRACT Electrcal tracg plays very mportat role the ope maret, as t creases the clarty ope maret ad promotes effcet system. Power flow s mportat etwor ad detfes the each ad every flow les s also mportat for future eeds ad system securty. So for that power flow tracg method of proportoal sharg prcple s performed o stadard bus systems ad detfes ts cotrbuto dvdual equpmets. The cotgecy process whch had bee raed the hghest mples that t cotrbuted to stablty of power system etwor. I ths paper, cotgecy wth cotrbuto of power system equpmet s proposed. Ths wll helps to tate the ecessary for cotrol actos order to mata power systems relablty, securty ad etwor stablty. Ths paper shows the performace of cotgecy selecto of sever trasmsso les, by calculatg the power (actve) performace dex. The computato s doe o load flow aalyss carred by usg method NR uder the MATLAB evromet. At most severed cotgecy s chose ad correspodg les flows ad voltages are obtaed for IEEE 4 bus system. Alog wth cotgecy power flow tracg s appled o system order to detfy the amout of cotrbuto of dvdual geerators to trasmsso les ad loads. The proposed cocept s ot lmted to cremetal chages ad t s applcable to both the powers eve set of buses suppled by same geerators are determed. Key words: Load flow aalyss, NR Method, Cotgecy rag, actve power performace dex, cotrbuto ad PFT. Cte ths Artcle: Dr.M.Veataswara Rao Ad Balla Moua, Cotrbuto of Geerators Power System Networ usg Power Flow Tracg Method, Iteratoal Joural of Mechacal Egeerg ad Techology 8( (8), 07, pp T/ssues.asp?JType=IJMET&VType=8&IType=8. INTRODUCTION Electrcty s ow commodty due to restructurg electrcal dustry. I the world, vertcal tegrated structure of power s beg replaced by maret structure. I maret vew operatos

2 Expermetal vestgato of heat trasfer coeffcet ad frcto factor a double ppe heat exchager wth ad wthout twsted tape serts usg zo-proplyee glycol aoflud t s more sgfcat to ow the cotrbuto of power to trasmsso les by dvdual geerators ad loads. Cotgecy s defed terms of uwated evets occurrg the etwor, due to ths sgle or more compoets a power system etwor are gog to be outage or loss for a short perod[]. I securty vew of systems, the cotgecy aalyses are to be performed to mata ad operate system safely. Geerato cotrbuto factor s used for securty ad cotgecy aalyses. Cotrbuto factors of dvdual geerators to le flows ad loads s calculated by usg the Dowstream tracg method[]. Essetal tas for the power system egeers s to estmate power system state uder cotgecy. These effects ca be predcted by cotgecy aalyss techque [3]. I ths paper, probablstc cotrbutos of geerators are foud by usg proportoal sharg method wth cotgecy aalyss approach for a power system etwor. Based o cotgecy rag dex the sever le s obtaed ad for that cotrbuto of geerators are to be performed. Proposed cocept aalyss s tested o IEEE 4 bus system ad ts effectveess s llustrated. I ths paper, secto presets the load flow aalyss wth best tradtoal method approach. Secto 3 dscuss about the cotgecy aalyss. Secto 4 dscuss about the PFT ad cotrbutos of geerators. Secto 5 gves the smulato results ad dscussos whereas Secto 6 cocludes the proposed wor.. POWER FLOW ANALYSIS Power flow methods are used for o lear equatos. Its ma obectve s to determe the agles ad ts voltages at each bus, real ad reactve power flow each trasmsso le ad le losses power systems for specfed bus codtos or termal codtos. Ma obectve of power flow studes are plag, operato ad cotrol. Other purposes are to compute steady state operatos[4]. It studes about the performace of the trasmsso les, trasformer ad geerator at steady state codtos[5]. Most of the methods are Gauss Sedel, Newto Raphso, Decouple, ad Fast Decouple. I these methods Newto method s a typcal method used for large power system to solve olear equatos mathematcs wth very favourable covergece because of less computer storage ad less covergece tme[6]. I order to measure the parameters of the power systems etwor at dfferet buses are obtaed by usg followg equatos th bus ected curret s expressed form of equato s I = = y v () I - th bus flowg curret, y - th bus admttace at ad buses, v - I polar form, the curret equato s wrtte as I = y = v θ + δ () Actve ad reactve power form of curret s expressed as I ( p q ) = (3) * v By substtutg (3) (), the equato s wrtte as th bus voltage 8 edtor@aeme.com

3 T. Vaya Sagar,Dr.Y.Appalaadu p q = v δ y v θ + δ (4) = Separatg real ad magary parts of power s p = = ( δ + δ ) y v v Cos θ (5) q = = ( + δ δ ) y v v S θ (6) Applg Taylor s seres ad expadg to the above equato about the tal estmate by eglectg the hgher order terms s as follows P ( ) P δ P ( ) = ( ) Q P δ ( ) Q P P δ V P P ( ) δ V δ P ( ) V δ P V ( ) ( ) V V The Jacoba matrx gves the learzed relatoshp betwee small chages voltage magtude wth small chages real ad reactve power P ad Q (7) δ ad P J = Q J 3 J δ J V 4 The dagoal ad off dagoal elemets of J are below ad smlarly we ca fd the dagoal ad off dagoal elemets for J,J ad J. P = δ = Y V V s P = YVV s δ ( θ δ + δ ) ( θ δ + δ ) 3. RANKING APPROACH BY CONTINGENCY ANALYSIS I the stage of plag, cotgecy aalyss s used to exame the performace of a system ad descrbe eed for a ew trasmsso expaso due to geerator expaso. Whle operatg stage, t asses to operate at a secure operatg pot ad how qualty stadards are power delvered to customers. I power systems, f the etwor compoets are overloaded the t s called as cogesto etwor[7]. Ths occurs due to overloadg of trasmsso le. The above problems power systems are allevate by evaluate the relatve stablty of a cotgecy[8]. Cotgecy aalyss ca be doe three stages of process. By ths process practcal vew ther wll ot be all les are over loaded or uder voltage ca be observed by aalyss of cotgecy method. I stage frst, cotgecy lst s prepared s ow as cotgecy creato. I secod stage fdg of severe cotgeces from all causg volato bus voltage & power through the trasmsso les s ow as cotgecy (8) (9) (0) 9 edtor@aeme.com

4 Expermetal vestgato of heat trasfer coeffcet ad frcto factor a double ppe heat exchager wth ad wthout twsted tape serts usg zo-proplyee glycol aoflud selecto. I thrd secto the ecessary cotrol ad securty actos are performed o most serve cotgeces power system etwors s ow as cotgecy evoluto[9]. 3.. Power performace dex ( PI mw ) The actve power performace dex s used for detfy the actve power flows through the trasmsso les[0]. Where max P L s PI MW N = L = w P PL L max () P max L = V * V X V - th bus voltage obtaed from the Newto Raphso method soluto th V - bus voltage obtaed from the Newto Raphso method soluto th th X - to buses reactace ad there are two types of sestvty factor (a) Geerator Outage sestvty factor ad (b) Le outage factor 3.. Process to determe rag usg Performace Idces Frst read system gve data of le ad bus. Perform the load flow aalyss, wthout cosderg the le cotgecy. Removg a le for outage or cotgecy ad proceedg to the ext step. For ths partcular outage, load flow aalyss s doe to calculate the actve power flow the remag les ad value of power flow MW ( PI mw ) s foud out. The actve power lmts volato of the system model tae to calculate the actve power performace dex (PI). Addg all values of PI each le outages of the system to computato severty dex. To obta the PI for all le outages are repeated from Steps 3 to 6. Calculated the values of the performace dces to gve cotgecy rag based o the severty dex. 4. POWER FLOW TRACING (PFT) Power flow tracg s a mportat process power systems. Now a day, a crease ubudlg of etwor of power systems, the power flowg from geerator to load ad geerator to trasmsso le has bee become serous ssue[]. I ths tracg power flows, geerator ad load tracg are two cases of comprses. Whle comg to geerator tracg, geerator to trasmsso les power flows are foud. The power trasfer from the load to trasmsso les s determed load tracg method. The PFT ca be doe some of the methods. But ths paper, PFT s doe by proportoal sharg prcple because t s very smple ad easy to fd the flow of real or reactve power PS etwor. Proportoal method tracg treats perfect mxer of commodty ode flows []. I Fgure (), the equato () represets the cotrbuto of flows P m ad P m to the outflows m respectvely. Smlarly, the equato (3) represets the cotrbuto of flows P m ad respectvely. P m to the outflows ml 0 edtor@aeme.com

5 T. Vaya Sagar,Dr.Y.Appalaadu P m P m l Fgure Proportoal sharg prcple P P m ml = P = P m ml P m P m Pm + P Pm + P m m Pm + P + P m Pm + P + P m m m () (3) Cotrbuto of dvdual equpmet s doe wheever some compoets falure a system ad ts operato costrats are volated. The the ma target s to trace the le from the system whch s overloaded ad power adustmets should be doe. Usually whle cosderg huge power system, there may be much umber of geerators ad loads whch are related to oe le power flow. So cotrbuto has bee come to pcture. Geerator cotrbuto power systems mpacts o a le ad t may also have egatve. Sce they are based o lberalzed DC model of the power system they ca oly be used for actve power[3]. 5. RESULTS Test o the sample IEEE-4 bus system etwor. It cossts of oe slac bus, four geerator buses, 9 load buses ad twety trasmsso les. From the stadard IEEE- 4 bus system data, the load flow aalyss s appled o t to determe trasmsso le power flow wth cotgecy aalyss Fgure IEEE-4 bus le power flow Fgure 3 IEEE-4 bus voltages Below table shows the rag for severe le the 4 bus system etwor ad most sever oe s raed frst. Here the severe le s 7-9 trasmsso les

6 Le umber Expermetal vestgato of heat trasfer coeffcet ad frcto factor a double ppe heat exchager wth ad wthout twsted tape serts usg zo-proplyee glycol aoflud Outage les (bus to bus) Table Cotgecy severty dex rag for IEEE-4 bus Overloaded les (bus to bus) Over loaded le flow (MVA) Le flow lmt (MVA) Performace Idex Severty Idex Rag Order The Cotgecy aalyss s performed for the tae 4 bus system ad t s otced that, whe the le 7 to 9 was ope, the flow o the le - has creased ad that most of the other le flows has also chaged. Due to the reasos Voltage levels are hgh, low reactace values ad hghest geerato capacty. Smlarly the trasmsso le from to 3 has less power flow. The reasos are low voltage values ad hgh reactace values. Eve the voltage values are chages ad bus umber 8 has hghest ad bus 3 has lowest voltages respectvely due to voltage level at ther respectve buses as show fg 3 edtor@aeme.com

7 T. Vaya Sagar,Dr.Y.Appalaadu Power flow tracg s coducted for 4 bus system ad cotrbuto of dvdual geerator share trasmsso le ad loads are determed. I below the tables wll shows ther share les ad loads alog wth the graphcal way. Here bus,,3,6 ad 8 are geerator buses ad remag are load buses so, the loads oly have ther share before ad after appled to power flow tracg method. Geerators share are chaged wthout ad wth cotgecy but overall load wll ot be chaged show table & 3. Fg 5 shows the 7-9 trasmsso le opeed ad the share of geerators each ad every trasmsso les. Table Geerator Cotrbuto for Loads wthout Cotgecy aalyss for IEEE-4 bus system Geerator No / Loads at Bus No G- G- G-3 G-6 G-8 TOTAL Table 3 Geerator Cotrbuto for Loads wth Cotgecy aalyss for IEEE-4 bus system Geerator No / Loads at Bus No G- G- G-3 G-6 G-8 TOTAL edtor@aeme.com

8 Expermetal vestgato of heat trasfer coeffcet ad frcto factor a double ppe heat exchager wth ad wthout twsted tape serts usg zo-proplyee glycol aoflud Table 4 Geerator Cotrbuto for trasmsso les wthout Cotgecy aalyss for IEEE-4 bus system Geerator No / Le No G- G- G-6 G-8 TOTAL Table 5 Geerator Cotrbuto For Trasmsso Les Wth Cotgecy Aalyss For Ieee-4 Bus System Geerator No / Le No G- G- G-6 G-8 TOTAL edtor@aeme.com

9 T. Vaya Sagar,Dr.Y.Appalaadu Fgure 4 IEEE-4 Bus Geerator Share Les 6. CONCLUSION Ths paper proposes the power flow tracg by proportoal sharg prcple for determg the dvdual geerator cotrbuto for all trasmsso les. The tracg methodology s based o the assumpto that, at ay etwor ode, the comg flows are proportoally dstrbuted amog the outgog flows. I ths method determato of real power flow from a partcular geerator to a partcular load. For power system securty, the cotgecy ad tracg assessmet s performed. REFERENCES [] S. Chellam ad S. Kalya, Power flow tracg based trasmsso cogesto prcg deregulated power marets, It. J. Electr. Power Eergy Syst., vol. 83, pp , 06. [] J. Hazra ad A. K. Sha, Electrcal Power ad Eergy Systems A rs based cotgecy aalyss method corporatg load ad geerato characterstcs, It. J. Electr. Power Eergy Syst., vol. 3, o. 5, pp , 00. [3] M. Al-sarray, H. Mhesa, ad R. Mcca, A Rs-Based Relablty Method for N-- Cotgecy Aalyss, o , pp. 0 4, 06. [4] G. D. Roh, B. Kathara, R. D. S. Rao, M. T. Studet, ad P. System, Trasmsso Le Cotgecy Aalyss Power system usg Fast ecoupled Method for IEEE-4 bus Test system., vol., o. 4, pp , 05. [5] D. C. Duvvada, Real power performace dex ad le stablty dex-based maagemet of cotgecy usg frefly algorthm, pp , 06. [6] X. Yag ad X. Zhou, Applcato of asymptotc umercal method wth homotopy techques to power flow problems, It. J. Electr. Power Eergy Syst., vol. 57, pp , 04.

10 Expermetal vestgato of heat trasfer coeffcet ad frcto factor a double ppe heat exchager wth ad wthout twsted tape serts usg zo-proplyee glycol aoflud [7] M. De ad S. K. Goswam, A Drect ad Smplfed Approach to Power-flow Tracg ad Loss Allocato Usg Graph Theory, Electr. Power Compoets Syst., vol. 38, o. 3, pp. 4 59, 00. [8] D. K. Tat, Load Flow Aalyss o IEEE 30 bus System, vol., o., pp. 6, 0. [9] P. Sehar, Power system cotgecy rag usg Newto Raphso load flow method, pp. 4, 03. [0] B. Krshaumar, M. Subaash, ad E. G. Kumar, Avalable ole at vol. 38, pp , 0. [] Y. Xao, X. Wag, X. Wag, ad C. Du, Trasmsso cost allocato by power tracg based equvalet blateral exchages, CSEE J. Power Eergy Syst., vol., o., pp. 0, 06. [] D. Krsche, R. Alla, ad G. Strbac, Cotrbutos of Idvdual Geerators to Loads ad Flows, vol., o., pp. 5 60, 997. [3] A. R. Abhyaar, S. A. Soma, ad S. A. Khaparde, Optmzato approach to real power tracg: A applcato to trasmsso fxed cost allocato, IEEE Tras. Power Syst., vol., o. 3, pp , Aug [4] Archaa Sgh, Prof. D.S.Chauha, Dr.K.G.Upadhyay, Effect of Reactve Power Valuato of Geerators Deregulated Electrcty Marets, Iteratoal Joural of Electrcal Egeerg ad Techology, Volume 3, Issue, Ja-Jue (0) [5] D.K. Tat, M.K. Verma, Bresh Sgh ad O.N. Mehrotra, Optmal Placemet of Custom Power Devces Power System Networ for Load ad Voltage Balacg, Iteratoal Joural of Electrcal Egeerg ad Techology, Volume 3, Issue 3, Oct Dec (0), 6 edtor@aeme.com