Aville online t www.sciencedirect.com ScienceDirect Procedi Technology 11 ( 2013 ) 672 679 The 4th Interntionl Conference on Electricl Engineering nd Informtics (ICEEI 2013) Use of Shunt Compenstor to Enhnce Power Trnsfer Cpility Limit, Cse: Jw Bli 500kV System Grid Mrwh Chyono,,*, Yenni Trid,, Mski Ngt c Muhmmd Nurdin, Nnng Hriynto PT PLN (Persero), Jkrt, Indonesi Institut Teknologi Bndung, Jln Gnesh No. 10, Bndung 40132, Indonesi c Centrl Reserch Institute of Electric Power Industry (CRIEPI), 2-11-1 Iwdokit Kome-shi Tokyo, Jpn Astrct Jw Bli 500kV power system grid comprises of two lrge res which re connected y two doule circuit trnsmission lines. However, under high power trnsfer from est to west re on Octoer 19, 2012 resulted in Jw Bli power system experienced voltge drop until 0.86 pu in west re. Very low voltge my led to voltge stility phenomenon. This pper would nlyze mximum power trnsfer cpility without nd with introducing shunt compenstors. Sttic nlysis using P-V Curve method is imed to ssess voltge stility phenomenon. P-V Curve corresponds with totl ctive power trnsfer (P) of two trnsmission lines connecting west nd est re compred to voltge system (V) ehvior in west re. The study lso includes investigtion of power trnsfer cpility limit enhncement with use of shunt compenstor compre to initil condition. Vrious options of shunt compenstors considered re MSCs, SVC, nd STATCOM. Power Trnsfer Stility Index nd Q-V Curve sensitivity were considered to cquire list rnking loction of shunt compenstor. Bsed on sttic voltge nlyses result, use of shunt compenstors ws proven to increse power trnsfer limit. 2013 The Authors. Pulished y y Elsevier B.V. Ltd. Open ccess under CC BY-NC-ND license. Selection nd peer-review under responsiility of of the Fculty of of Informtion Science & Technology, Universiti Kengsn Mlysi. Keywords : Power trnsfer; P-V Curve; Q-V Curve; Power Trnsfer Stility Index; MSCs; SVC; STATCOM * Corresponding uthor. E-mil ddress: mrwhes06@yhoo.com 2212-0173 2013 The Authors. Pulished y Elsevier Ltd. Open ccess under CC BY-NC-ND license. Selection nd peer-review under responsiility of the Fculty of Informtion Science & Technology, Universiti Kengsn Mlysi. doi: 10.1016/j.protcy.2013.12.244
Mrwh Chyono et l. / Procedi Technology 11 ( 2013 ) 672 679 673 1. Introduction Indonesi, s developing country, hs verge energy growth out 8.3 % in the lst 5 yers, from 2007 until 2011. 74% of the totl energy ws consumed in Jw Bli power system [1]. However, lod center of Jw Bli power system is locted in west re nd power must e trnsfer from est re to fulfill the demnd. West nd est res re connected in 500kV system through two trnsmission lines (TL) i.e. doule circuits TL. Ungrn- Mndirncn nd doule circuits TL Pedn-Tsik. Bsed on Jw Bli system evlution on Octoer 19, 2012 [2] shown in Fig. 1. As power trnsfer est to west re ws incresed, voltge system in west re ws decresed. Voltge dropped until 13% s the highest trnsfer 2900MW t 11.00 m, ut in the lowest trnsfer 2000MW, voltge ws in norml rnge (±5%), reltively. The system condition under high trnsfer presented vulnerle system which my threten voltge instility system. The min ojective of this pper is to nlyze mximum trnsfer limit est to west re for se cse condition nd to nlyze effects ddition of shunt compenstors in incresing trnsfer cpility limit. Fig. 1. Trnsfer Est to west re vs Voltge profile system in west re. Voltge Stility is common issue in developing power system. Voltge stility sometimes refers to lod stility, corresponding with lnce of rective power. Voltge stility is often distinguished into 2 ctegory sed on time frme, i.e. trnsient voltge stility (0-10 seconds) nd long term voltge stility [3, 4]. There re vrious common voltge stility nlysis methods i.e. P-V Curve nlysis, Q-V Curve nlysis, modl nlysis, nd timedomin nlysis [4]. Some of spect influencing voltge stility system re sufficiency of the rective power supply nd control, s well lod chrcteristic. Beside P-V Curve nd Q-V sensitivity, power trnsfer stility index (SI) is included in this nlysis of study cses. SI is prmeter estimting proximity operting point condition to instility voltge point. Mny litertures hve proposed method of prediction voltge instility. First reltionship etween voltge stility indices nd multiple lod flow solution in electric power hs een studied firstly y Y. Tmur [5]. Some of other predictions for proximity to dynmic voltge collpse known re sed on voltge stility index [6], power trnsfer stility index [7, 8] nd power mrgin [9]. A simple Thevenin equivlent network consisted of line Thevenin impednce connecting slck us nd lod us is shown in Fig.2. This illustrtion is used to derivte mximum trnsfer power nd SI index [8, 10] s seen in equtions elow. Fig.2. Two Bus Equivlent System
674 Mrwh Chyono et l. / Procedi Technology 11 ( 2013 ) 672 679 Mgnitude of power trnsfer lod with fctor of lod cosφ is given y (1) Mximum power trnsfer occurred t condition:, yields mgnitude impednce lod is equl to mgnitude impednce line (Z L = Z th ). Therefore, cquired mximum power trnsfer: (2) Power Trnsfer Stility Index (SI), yields: (3) The vlue of SI mentioned in Eqution (3) vries etween 0 (no lod cse) to 100% (voltge collpse point). 2. Approch nd methodology 2.1. Softwre simultion This reserch ws conducted in CRIEPI-Jpn (Centrl Reserch Institute Electric Power Industry) utilizing CPAT progrm. CPAT is simultion nlyticl power system progrm developed y CRIEPI. CPAT provides pckge tools such s lod flow nlysis using the Newton Rhpson method which hs cpility in multiple lod flow solution nd P-V Curve nd Q-V curve nlysis [11]. One of superiorities CPAT is SI clcultion included in lod flow result simultion. 2.2. Determintion cndidte loction nd cpcity of shunt compenstor One of solutions to enhnce power trnsfer cpility limit is use of shunt compenstor [10, 12]. To determine loction cndidtes of shunt compenstor, P-V Curve wide re, SI nd Q-V Curve Sensitivity re considered. This study would use two cses tht were under low power trnsfer nd under high trnsfer. Both lod flow result simultions would provide voltge stility index in lod usses. After getting list rnking nodes from P-V Curve wide re nd SI, Q-V Curve locl lod usses re showed to compre the sensitivity us to rective power chnge. Herefter, determintion cpcity of rective y prediction rective power required to rech voltge 1pu in cndidte nodes resulted from fictitious synchronous condenser t nodes under outge one circuit of trnsmission lines Ungrn-Mndirncn. 2.3. Clcultion of criticl point power trnsfer (P-V Curve Wide Are) Creting P-V curve wide re is imed to nlyze the impct of trnsfer loding to voltge ehvior t receiving re or west re. Axis Y on P-V Curve represented P or totl ctive power from est to west re flowing vi trnsmission lines Ungrn-Mndirncn, nd Pedn-Tsik, while xis X represented V or ehviour of mgnitude voltge nodes in west re. To crete P-V curve, this study uses se cse under low trnsfer (08.00 m). Scenrio of construction P-V Curve wide re did y incresing lod demnd in west re until 200% incrementlly, nd lnced y incresing power genertion in est re. In this study, power genertion in est re ws ssumed unlimited, wheres lod model, rective power cpility AVR, exciter of genertion units were considered s well.
Mrwh Chyono et l. / Procedi Technology 11 ( 2013 ) 672 679 675 This study exmined use supplement nd control rective power, i.e. shunt compenstor s proposed study. Vrious options of shunt compenstor considered included mechniclly switched cpcitors (MSCs), Sttic Vr Compenstor (SVC), nd STATCOM, either norml condition or outge one circuit TL.Ugrn-Mdcn. 3. Result nd discussion 3.1. Bse Cses nd Scenrios Study 3.1.1 SI Index Lod flow result simultion oth under low nd high trnsfer presented SI indices. Cndidte loctions of the 8 highest SI of se cses re shown in Tle 1, s follows: Tle 1. Voltge Stility Index (SI) sed on rnking list SI CBTU CWG BKS KBGN GDNL CRTA BDSN BLJA SI (%) High Trnsfer 89.2 86.4 85.6 83.8 83.6 82.9 78.5 77.8 SI (%) Low Trnsfer 62.0 51 52.1 49.1 37.2 52.8 47.7 37.2 3.1.2 P-V Curve Wide Are Result of P-V Curve wide re for se cse or without shunt compenstor is illustrted in Fig.3. Criticl mximum power trnsfer reches 3100MW nd mximum power trnsfer within norml rnge voltge drop system (-5%), is only 2194MW. However, lower trnsfer cpility occurred under N-1 TL. Ugrn-Mdcn is out 2590MW. In ddition, rnking from the lower P-V Curve re Citu, Beksi, Cwng, Cirt nd Sguling. Fig. 3. PV Curve Wide Are () Norml Lines nd () N-1 TLUngrn-Mdcn
676 Mrwh Chyono et l. / Procedi Technology 11 ( 2013 ) 672 679 3.1.3 Q-V Curve Locl of Lod Busses Fig. 4. Q-V Curve of Lod Busses of Bse Cses () under low trnsfer nd () high trnsfer Q-V Curve of the 8 usses with high SI result is depicted in Fig. 4. Slope of Q-V Curve under high trnsfer is less thn under low trnsfer. It represents tht operting point is ner to criticl point of voltge instility. The slope of curve indictes sensitivity of lod us to rective power chnge. Bsed on Q-V Curve locl lod usses, otined rnking of criticl uses, s depicted in Tle 2. Tle 2. Voltge Stility Index (SI) sed on rnking list Sensitivity CWG CRTA BDSLN KBGN CBTU BLJA BKS GNDL V/ Q High Trnsfer 0.000431 0.000388 0.000384 0.000376 0.000304 0.000292 0.000279 0.000254 V/ Q High Trnsfer 0.000259 0.000254 0.000255 0.000232 0.000194 0.000207 0.000177 0.000158 By considering simultion result of voltge stility indices, P-V Curve wide re nd locl Q-V Curve, cquired 8 list cndidte loction s the min priority loctions of shunt compenstor, tht re Cwng, Cirt, Bndung Seltn Kemngn, Citu, Blrj, nd Gndul. All cndidtes locted in west re represented vulnerility condition to voltge instility due to lck of rective power in west re. There re 4 scenrios rrnged to exmine impct of shunt compenstor to enhnce power trnsfer limit, following s: 1. Use of MSCs 1150 MW, 25MVr/nk (CWG 100MVr, CRTA 200MVr, KBGN 200MVr, CBTU 275 Mvr, BDSLN 200MVr, BLJA 175 MVr) 2. Use of switch cpcitor 1150 MW with 50MVr/nk (CWG 150MVr, CRTA 200MVr, KBGN 200MVr, CBTU 275 Mvr, BDSLN 200MVr, BLJA 150 MVr) 3. Use of SVC 1200 MW (Cwng 500MVr, Cirt 500MVr) 4. Use of STATCOM 1200MW (Cwng 500MVr, Cirt 500MVr).
Mrwh Chyono et l. / Procedi Technology 11 ( 2013 ) 672 679 677 3.2. Use of Shunt Compenstor 3.2.1 Scenrio-1 with MSCs 1150 MVr, 25 MVr/nk Fig. 5. P-V Curve Wide Are with MSCs () Under Norml Lines nd () Under N-1 TL.Ungrn-Mdcn MSCs 1150MVr comprised of cpcitor nk 25 MVr shown in Fig.5. The P-V curve represents step ction of switched nks. Criticl power trnsfer from est to west re ttins until 3995MW, incresed 850MW from the se cse. In order to operte within norml rnge voltge (-5%), mximum trnsfer power is only out 3200MW. Step curve s seen in P-V Curve, Fig.5 is n effect of step ction of switch cpcitor. As depicted in Fig.5, under condition N-1 TL Ungrn-Mndirncn, criticl mximum trnsfer power is 3307MW. 3.2.2 Scenrio-2 with MSCs 1150MVr, 50 MVr/nk Scenrio-2 is similr with scenrio-1 the distinction is only in cpcity ech unit nks, tht is 50Mvr per unit nk, so tht numer of unit nk decresed. There is no significnt effect to mximum trnsfer ility. With sme totl cpcity, in scenrio-2 hs similr trnsfer limit with scenrio-1 out 3900MW, s shown in Fig. 6. The distinction of oth figures, step response using lower cpcity unit nk hs smoother step P-V Curve. However, if required within norml rnge voltge, then mximum power trnsfer is only 3400MW. Under N-1 TL Ungrn- Mdcn s drwn in Fig. 6, power trnsfer limit is out 3340 MW, increses out 750MW from se cse trnsfer limit ility.
678 Mrwh Chyono et l. / Procedi Technology 11 ( 2013 ) 672 679 Fig. 6 P-V Curve Wide Are with MSCs () under Norml Lines nd () under N-1 TL.Ungrn-Mdcn 3.2.3 Scenrio-3 with SVC 1200Mvr nd Scenrio-4 with STATCOM 1200MVr Simultion result of use of SVC nd STATCOM re depicted in Fig.7 () nd (), respectively. It shows SVC nd STATCOM which hve thyristor give smooth ction to mintin voltge t desired s incresed lod. Mximum power trnsfer oth SVC nd STATCOM rech out 3900MW. It mens, in sttic nlysis, there ws no significnt difference etween use of SVC nd STATCOM. However, s power trnsfer more thn 3250 MW, SVC opertes s fix cpcitors indicted voltge dropped following incresed power trnsfer. Fig. 7. () P-V Curve Wide Are with SVC 1200MVr; () P-V Curve Wide Are with STATCOM 4. Conclusion This pper exmines criticl point power trnsfer to west re through trnsmission lines UGRN-MDCN nd PDN-TSK in Jw-Bli 500kV grid system. Sttic nlysis method is used to ssess voltge stility phenomen. The study includes investigtion of se cse condition without compenstor nd with use of shunt compenstor to enhnce trnsfer limit. Vrious options of shunt compenstors include MSCs, SVC, nd STATCOM. Bsed on stedy stte nlysis result of voltge stility shows mximum power trnsfer est to west re for existing condition is 3100 MW, while under condition N-1 TL. UGRN-MDCN is 2590MW. Considering P-V Curve wide re, SI, nd Q-V Curve, plcement of shunt compenstors re locted in west re indicting lck of rective power control in west re. Use of MSCs 1150MVr, SVC 1200MVr, nd STATCOM 1200MVr proven hd impct to increse power trnsfer cpility limit, ut SVC nd STATCOM hs smoother response to control voltge to
Mrwh Chyono et l. / Procedi Technology 11 ( 2013 ) 672 679 679 chnge lod. Bsed on sttic nlysis, however, SVC nd STATCOM hve similr cpility to enhnce power trnsfer limit out 3900MW. Acknowledgements I would like to express my grtitude to PT. PLN (Persero) for the sponsorship, to CRIEPI for the opportunity to tke reserch, nd ll CRIEPI s memer for discussion, s well Plnning Opertion Deprtment PT PLN (Persero) P3B Jw Bli for the dt relted to reserch nd other support. References [1] PT.PLN (Persero), PLN Sttistics 2011, 2012 [2] PT.PLN (Persero) P3B Jw Bli, Monthly Opertion Evlution, Novemer, 2012. [3] Tylor Crson W,Power System Voltge Stility, The EPRI Power System Engineering Series. McGrw-Hill, Inc., 1994. [4] Khundur. P,Power System Stility nd Control, McGrw-Hill, New York, USA, 1994 [5] Tmur Y., Mori H., Iwmoto S., Reltionship etween Voltge Instility nd Multiple Lod Flow Solutions in Electric Power Systems, IEEE Trns. on PAS, Vol.102, No.5, My 1983, pp.1115-1125 [6] Blmourougn, V., Sidhu T.S., Schdev, M.S. 2004. Technique For Online Prediction of Voltge Collpse. IEE Proc-Genertion, Trnsmission, Distriution, 151(4): 453-460. [7] Moghvvemi M, Omr F.M, Technique for Contingency Monitoring nd Voltge Collpse Prediction IEEE Proceeding on Genertion, Trnsmission nd Distriution, Vol. 145, N6, pp. 634-640 Novemer 1998 [8] Nizm M, Mohmed A., Hussin A., Dynmic Voltge Collpse Prediction on Prcticl Power System Using Power Trnsfer Stility Index,IEEE, 5th Student Conference on Reserch nd Development- SCORed 2007 [9] Bergovic M., Milosevic B., Novosel D., 2002., A Novel Method for Voltge Instility Protection, Proceeding of the 35th Hwii Interntionl Conference on System Science. (HICSS'02). [10] Vn Cutsem T., nd Vourns C.,Voltge Stility of Electric Power Systems, Kluwer cdemic pulishers, Boston, USA, 1998. [11] CRIEPI (Centrl Reserch Institute of Electric Power Industry),Mnul Book of CRIEPI s Power System Anlysis Tools (CPAT), H22 Version [12] Au-Sid A nd Chtur Krunr, Improvement of Trnsmission Line Power Trnsfer Cpility, Cse Study, Electricl nd Electronics Engineering Interntionl Journl (EEEIJ), My 2012,Vol.1, No.1