Intenational Jounal on Technical and Physical Poblems of Engineeing (IJTPE Published by Intenational Oganiation of IOTPE ISSN 77-358 IJTPE Jounal www.iotpe.com ijtpe@iotpe.com ecembe 13 Issue 17 Volume 5 Numbe 4 Pages 35-41 TRANSIENT STABILITY IMPROVEMENT OF POWER SYSTEM USING BASE FAULT CURRENT LIMITER M. Jafai 1 M.R. Aliadeh Pahlavani 1. Faculty of Electical and Compute Engineeing, Univesity of Tabi, Tabi, Ian, m.jafai87@ms.tabiu.ac.i. Malek Ashta Univesity of Technology, Tehan, Ian, m_aliadehp@iust.ac.i Abstact- In this pape, tansient stability impovement using Supeconducting Magnetic Enegy Stoage based Fault Cuent Limite (-based FCL is pesented. The poposed -based FCL is installed at the beginning of faulty line. The poposed -based FCL insets a supeconducting inductance into the fault cuent pass. The insetion of high value of inductance not only limits the fault cuent level in an acceptable level but also impoves tansient stability of powe system by stoing excessive enegy of synchonous geneatos duing the fault. Moeove, the poposed FCL can impove the voltage pofile duing shot cicuit faults. Analytical analysis of the FCL s pefomance ae pesented in detail and simulation esults in the IEEE standad 14-bus system using EMTC/PSCA softwae ae included to show the cuent limiting featue, voltage sag pevention and tansient stability enhancement using the poposed -based FCL. Keywods: Fault Cuent Limite, Magnet, Tansient Stability Impovement, Voltage Pofile. I. INTROUCTION Nowadays, due to consideable incease in electic powe demand, powe systems have become moe complicated. To suppot powe demand, moden systems must be connected each othe. In addition, geen esouce enegies and diffeent types of distibuted geneation such as sola enegy and wind enegy have been intoduced. This may inceases powe flow and shot cicuit capacity of the powe netwoks. So, occuing a shot cicuit fault in the powe lines esults in vey high-level fault cuents, which flow in the powe system seies equipment and may damage them [1-4]. Using fault cuent limite (FCL is a pomising way to ovecome the high-level shot cicuit cuents and pevent the high costs of switchgea eplacement in powe systems [5-8]. Solid state, supeconducting (esistive type and inductive type and esonance type FCLs have been pesented in [7] to [11]. Using a supeconducting C eacto in solid state fault cuent limite educes inceasing ate of fault cuent until the opeation of cicuit beakes. uing fault cuent limiting mode, active powe is absobed by supeconducting C eacto. To each bette limitation of such FCLs, lage value of C eacto must be taken into account. Low powe losses and no need to quenching chaacteistics of supeconductos ae main advantages of the mentioned FCL [1, 13]. By inceasing the value of inductance in inductive type supeconducto, stoed electical enegy can be inceased. This is the main idea of supeconducting magnetic enegy stoage (. Feie has pesented technology in 1969. Howeve, moe studies on this field illustated that the has bette pefomance in powe system opeating applications than the enegy stoage application [14-18]. One of the applications of technology is using its supeconducting eacto in FCL stuctue [19, ]. technology can poduce C eacto with lage value, which is needed in solid state FCLs. Such eacto will have lage value and low losses due to its supeconducting chaacteistic. Main applications of FCLs in addition to limiting the fault cuent ae tansient stability enhancement of the powe system, powe quality and eliability impovement [1,, 1]. Inceasing powe flow in the powe lines due to inceasing powe demand can affect the stability of the powe system especially duing lage distubances such as shot cicuit faults. Most of studies on this issue have focused on supeconducting FCLs (SFCLs which opeate by quenching of supeconducto. Base of all of these stuctues is to limit the fault cuent, estoe the bus voltage, and absob active powe of geneatos duing the fault. This action can help the geneato to maintain its stability. Theefoe, tansient stability of powe system will be impoved in shot cicuit conditions [-6]. Howeve, these FCL stuctues have two main poblems. Fistly, they make the supeconducto to change fom supeconducting state to nomal state and vise vesa, which leads to powe losses. Secondly, they have ecovey time due to quenching phenomenon. Recovey time leads to moe time equied by FCL to eteat fom the powe system and this makes distubance in voltage pofile. In this pape, a -based FCL is applied to enhancement of IEEE standad 14-bus powe system s tansient stability. Maximum oscillation of angula fequency of all geneatos has been consideed as a citeion to show the effectiveness of the poposed stuctue. 35
Intenational Jounal on Technical and Physical Poblems of Engineeing (IJTPE, Iss. 17, Vol. 5, No. 4, ec. 13 It is obseved that using technology can help the limiting chaacteistics of FCL and impoves the tansient stability of system. In addition, this FCL can help to impove voltage pofile in fault condition. Aveage voltage sag on system buses duing the fault is measued to show this capability of poposed FCL. Such stuctue has not ecovey time and has low powe losses in compaison with the othe stuctues, which ae used fo this pupose. The analytical analysis fo FCL opeation and tansient stability analysis ae pesented in detail. simulation study on IEEE standad 14-bus powe system including the poposed FCL is established using EMTC/PSCA softwae. Results ae discussed caefully to show the pefomance of the poposed FCL on the tansient stability impovement. II. POWER CIRCUIT TOPOLIGY AN PRINCIPLES OF OPERATION A. Powe Cicuit Topology The thee-phase powe cicuit topology of the poposed FCL is shown in Figue 1. This stuctue is composed of thee main pats, which ae descibed as follows: 1- The thee-phase tansfome in seies with the system that is named Isolation tansfome - The thee-phase diode ectifie bidge 3- A magnet as C eacto with lage value As a conventional method, isolation tansfome is needed to diect the line cuent to cuent limiting pat. Thee-phase diode bidge is AC/C conveting tool fo FCL and magnet is the main pat of FCL which has the cuent limiting task duing the shot cicuit fault. B. Pinciples of Opeation In nomal opeation of powe system, diode bidge ectifies line cuent to C cuent and this C cuent chages magnet. When the C cuent eaches to the peak of line cuent, magnet behaves as shot cicuit because of its supeconducting chaacteistic and so, voltage dop on it becomes almost eo. Vey small voltage dop on magnet is due to C cuent ipple. By this way, total voltage dop on FCL will be elated to voltage dop on diodes and isolation tansfome, which is negligible in compaison with feede s nominal voltage. Theefoe, FCL has not consideable effect on the nomal opeation of powe system. As fault occus, line cuent stats to incease. Howeve, the magnet limits its inceasing ate and pevents fault cuent apid incement. In this case, fault enegy will be stoed in magnet. Since the value of magnet is lage, this cuent limitation is in acceptable ange, which will be shown in simulation esults. By this manne, the voltage of connected bus does not expeience consideable sag in compaison with the case of no FCL. Theefoe, powe flow in system will be not inteupted by the fault and tansient stability of system will be impoved. By emoval of the fault, system etuns to its nomal state and magnet stats to dischage. Since the magnet is in its supeconducting state duing the fault and has not quenching phenomenon, thee will not be any ecovey time and so, just afte fault emoval, FCL eteats fom the system. A B C Isolation Tansfome i (t dc 4 6 iode Bidge V dc Lsmes Magnet Cyostat i (t L 5 1 3 Pimay Side Seconday Side Figue 1. Thee-phase powe cicuit topology of the poposed FCL III. ANALYTICAL ANALYSIS OF THE PROPOSE FCL This section deals with the analytical analysis of the poposed FCL s pefomance in cuent limiting duing the fault. To calculate the equation of line cuent and C cuent, two modes ae consideed as Pe-Fault Condition, and Fault uation. A. Pe-Fault Condition In pe-fault condition, line cuent, i L (t, and C cuent, i dc (t have two modes as Chaging mode and ischaging mode. C cuent and diodes cuents ae shown in Figue. Enlaged view of these cuents is shown in Figue 3. Chaging mode begins at t and ends at t 1. In this mode, one diode fom each phase is ON. So, the following equation can be witten. di( t Vmsin( t i( t L V (1 whee, i = i dc = i L, = s + FCL + L, L = L S + L + L L, s and L s ae souce side s esisto and inducto, espectively, L and L L ae load side s esisto and inducto, espectively, FCL is equivalent esistance of FCL s elements and V is voltage dop on each diode. Solving Equation (1 leads to: ( t t V ( L m V i t e ( I sin( t Vm V sin( t whee, I i( t, ( L, tan ( L/. ischaging mode stats at t 1 and continues to t. In this mode, both diodes of each phase ae ON and theefoe the line cuent is sinusoidal wavefom and FCL behaves as a seies tansfome with shot-cicuited seconday. In such condition, C cuent diffeential equation can be deived as follow: didc idc V (3 whee, is the diode s esistance. Note that its value is vey small. By solving Equation (3, C cuent fomula will be as follow: 1 ( 36
Intenational Jounal on Technical and Physical Poblems of Engineeing (IJTPE, Iss. 17, Vol. 5, No. 4, ec. 13 ( tt1 dc ( ( max / / i t e I V V (4 Consideing chaging and dischaging modes of cuent, it is possible to calculate the aveage value (I dc and ipple (i of C cuent. As it is obvious, C cuent s ipple leads to voltage dop on magnet and theefoe on FCL. Fo I dc and i, we can wite: i Idc Imax (5 1 i ( Imax I (6 whee, I max is the peak of line cuent. I in Equation (6 can be calculated fom Equation (4 in t instant as follow: ( tt1 L V V ( max I e I (7 By consideing that e -x (1-x and t - t = T / 6, whee T is the time peiod of powe system, Equation (7 can be simplified to Equation (8. V V I (1 T / 9 ( Imax (8 Theefoe, i can be deived fom combination of Equations (6 and (8. T V i ( ( Imax L (9 It is impotant to note that its value is vey small due to vey small value of /L. Consideing Equation (9, the voltage dop on magnet can be calculated as Equation (1. V V 4 ( Imax L (1 By using Equation (9, fomula of I dc can be witten as follow: T TV Idc Imax (1 L L (11 It is obvious that the aveage of magnet s cuent is vey close to the peak of line cuent. This value can be used fo designing the magnet. B. Fault uation Consideing Figue 4, fault occus at t f. The fault condition has two modes as M 1 and M. The mode M 1 is in t 3 to t 4 time inteval and in this mode, diodes 4 and 5 ae ON, while 1,, 3 and 6 ae OFF. Theefoe, cuent of phase B is equal to negative value of cuent of phase A and cuent of phase C is eo (Figue 5. The eo sections, which ae appeaed in the line cuent, ae due to the commutation of diodes. In the nomal opeation, commutation of diodes was based on thei cuent, while, in the fault condition, thee will be voltage commutation on diodes. In such condition, fomula of cuent of phase A can be witten as follow: dia sin( ( ( t Vm t ia t L V (1 ( t t 3 Vm V i ( L A t e ( I3 sin( t3 Vm V sin( t whee, 1 s FCL, L Ls Lsmes, I ia ( t 3 3 (13 ( L, tan ( L/ and. Note that the C cuent elation is same as cuent of phase A in this mode. Fo phase B and C, as pointed peviously, i B (t = -i A (t and i C (t =. In mode M, iodes 4 and 1 ae in commutation, 5 is ON and othe diodes ae OFF. Theefoe, one diode fom each phase is ON and theefoe, sum of phases cuent is eo (Figue 5. The line cuent in this time inteval follows in the Equation (14. Cuent Idc Id1 Id Id3 Id4 Id5 Id6 M1 Figue 4. C cuent and diodes cuents in the fault condition M tf t3 t4 t5 Idc A phase B phase C phase Idc Id1 Id Id3 Id4 Id5 Id6 Cuent Cuent Figue. C cuent and diodes cuents in the nomal opeation of powe system Figue 3. Enlaged view of Figue Figue 5. Line cuent and C cuent in the fault condition tf t3 t4 t5 ( t t 4 Vm V i ( L A t e ( I4 sin( t4 (14 Vm V sin( t whee, I 4 = i A (t 4. Simila to the pevious mode, C cuent follows the cuent of phase A elation. The cuents of phase B and C can be diven fom Equation (14 with coesponding phase shift. This manne of vaiation will be epetitive fo next steps in the fault condition. 37
Intenational Jounal on Technical and Physical Poblems of Engineeing (IJTPE, Iss. 17, Vol. 5, No. 4, ec. 13 IV. TRANSIENT STABILITY ANALYSIS USING THE PROPOSE FCL In this section, it will be shown that the poposed FCL can impove the tansient stability of powe system by absobing the enegy duing fault and estoing the voltage of connected bus. It is possible to model the FCL by a esisto duing the fault, but it should be consideed that this esisto is not an odinay esisto and should be calculated. Fo this calculation, we used the elation of enegy stoed in magnet duing the fault as follow: 1 w I ( whee, w is the enegy stoed in magnet duing the fault and I is the magnet s cuent duing the fault and can be witten as Equation (16, appoximately. I Imax t (16 whee, V dc is the C side voltage ectified by the diode bidge. So, the instantaneous powe of magnet can be concluded as follow: dw Pdc Imax t L (17 Consideing Equation (17 and fault duation equal to t f, aveage of active powe absobed by magnet will be as Equation (18. Pdc, ave Imax t f (18 Finally, consideing the fact that the AC side and C side active powes ae equal and V dc is equal to: 6 sin( Vm (19 3 whee, R fcl (the model of poposed FCL duing the fault in its ac side can be concluded as Equation (. Vm Rfcl ( 3 3V m 3( Imax t f Lsmes It is impotant to note that this esisto has minimum and maximum limits as follows: Rfcl Vm (1 3Imax Consideing Equations (, (1 and (4, lage value of L will lead to lage value of R fcl and consequently bette limitation of fault cuent and bette enhancement of tansient stability. Howeve, lage value of L will incease the design and constuction difficulties and costs. Theefoe, the value of L should be selected consideing the maximum acceptable fault cuent. In othe wods, the maximum line cuent and minimum time in which the cicuit beakes can open the line should be detemined and then the value of L should be calculated by using Equation (16. To show the effectiveness of the poposed FCL, Sum of the Maximum Oscillation (SMO of all geneatos has been consideed as a citeion fo the stable powe system with and without the poposed FCL. Theefoe, fo the unstable powe system, without the poposed FCL, the mentioned citeion will be infinite. Consideing Figue 6, the maximum oscillation of a geneato can be witten as follow: ( i max, i min, i whee, ω i is angula fequency of geneato i. By using the poposed FCL, it will be shown in the simulation esults that the sum of Δω i fo all geneatos (i fom 1 to 5 can be educed, and as a esult, tansient stability of the powe system will be impoved. SMO fo all geneatos can be expessed as Equation (3. 5 SMO i1 i (3 As mentioned above, SMO will be infinite fo an unstable system. Howeve, If SMO citeion is deceased by using the poposed FCL, it can be concluded that the FCL impoves the tansient stability of the powe system. Angula fequency ωmax,i ωmin,i Δωi Figue 6. Schematic oscillation of a geneato afte fault Figue 7. IEEE standad 14-bus powe system V. SIMULATION RESULTS Simulations using EMTC/PSCA softwae ae pefomed on Figue 7. Consideing the histoy of measuements on system, it is assumed that the line between buses 7 and 9 is moe supposed to shot cicuit faults. To study the pefomance of poposed FCL on cuent limitation and tansient stability impovement, a thee-phase to gound fault is consideed at t = 6 sec. with the duation of. sec. (1 cycles of powe fequency in this line. In this simulation, value of L is calculated.48 H consideing Equation (17 in section IV. Two sets of the poposed FCL ae installed at two end of line 7-9. 38
Intenational Jounal on Technical and Physical Poblems of Engineeing (IJTPE, Iss. 17, Vol. 5, No. 4, ec. 13 Figue 8 shows the fault cuent without using the poposed FCL. In addition, Figue 9 shows the line 7-9 cuent fom the bus 7 side. The cuent, which is flowed fom bus 9 to the faulted point, is simila to Figue 9. Consideing these figues, line cuent is inceased extemely duing the fault, which may cause the instability of geneatos. Figue 1 shows the geneato 1 and angula fequency in such condition. This figue shows that the synchonous geneatos angula fequencies stat to incease uncontollably and become unstable. To show effect of fault on synchonous compensatos, thei angula fequencies ae shown in Figue 11. Accoding to this figue, duing the fault, the lines esistance because of high shot cicuit cuents that causes a decement on thei angula fequency absobs synchonous compensatos kinetic enegy. Afte fault emoval, they stat to oscillate aound the system base fequency and etun to thei nomal state. Note that since the synchonous compensatos do not povide active powe fo the system, they will be unstable in shot cicuit faults. Howeve, afte instability of geneatos and powe system inteuption, synchonous compensatos speed declines to eo. Moeove, the fault causes deep voltage sag on system buses. This voltage sag is moe citical on buses, which ae connected to the faulty line. Buses 7 and 9 voltages duing the fault ae shown in Figues 1 and 13, espectively. In geneal, instability of the geneatos is obvious fom maintained figues. Cuent (ka Cuent (ka Figue 8. Thee-phase fault cuent without using FCL Figue 9. Fault cuent fom bus 7 to the faulted point without using FCL Angula fequency (ad/s 1 5-5 -1 1 5-5 -1 35 35 3 Geneato 1 Geneato 5 6 7 8 9 1 Figue 1. Gen. 1 and angula fequency afte fault without using FCL Angula fequency (ad/s Cuent (ka Figue 11. Angula fequency of synchonous compensatos without using FCL 3 - -3 33 3 31 3 Condenso 5 Condenso 4 Condenso 3 5 6 7 8 9 1 (s Figue 1. Voltage of bus 7 duing the fault without using FCL 3 - -3 Figue 13. Voltage of bus 9 duing the fault without using FCL 1 5-5 -1 Figue 14. Fault cuent by using the poposed FCL By using the poposed FCL and consideing the magnet s value equal to.48 H fault cuent is limited as shown in Figue 14. This leads to limitation of cuent flowed fom the system to the faulted point. Fo instance, the fault cuent fom bus 7 is shown in Figue. This effective limitation of fault cuent helps the geneatos to maintain thei stability (Figue 16. In addition, as shown in this figue, the synchonous compensatos expeience vey small deviation fom the base fequency. Figues 17 and 18 ae shows voltage of bus 7 and 9 duing the fault situation in pesence of the poposed FCL. Accoding to these two figues, voltages of these buses ae estoed popely. Because of these figues, using FCL pevents the instability of geneatos and impoves the tansient stability of whole system. In addition, the SMO index, voltage sag pevention, and cuent limiting esults in fault condition fo the poposed -based FCL ae pesented in Table 1. The SMO index is calculated using Equation (3. To study the voltage sag pevention capability of poposed FCL, aveage of voltage sag on all powe system buses ae calculated as follow: 39
Intenational Jounal on Technical and Physical Poblems of Engineeing (IJTPE, Iss. 17, Vol. 5, No. 4, ec. 13 14 ave 1 N F N Vsag Vk Vk V k (4 14 k1 In addition, Equation (5 assesses cuent limiting pefomance of FCL. F N I I / I (5 F Cuent (ka max max Figue. Cuent of bus 7 to the faulted point with the poposed FCL Angula fequency (ad/s Figue 16. Geneatos 1 and and synchonous compensatos angula fequency with the poposed FCL 1 5-5 -1 3 316 3 314 313 31 - -3 G1 G SC3 SC4 SC5 5 6 7 8 9 1 Figue 17. Voltage of bus 7 duing fault with the poposed FCL 3 - -3 Figue 18. Voltage of bus 9 duing fault with the poposed FCL As pointed peviously, without using FCL, system becomes unstable and SMO index will be infinite, while by using FCL it is deceased to 4.197 (ad/s. Aveage voltage sag is educed fom 56.8 % in no FCL condition to 5.71 % with using the poposed FCL. Impovement of voltage pofile duing the fault is obvious fom these esults. In addition, cuent limiting capability of FCL is pesented in Table 1. The fault cuent is limited to about 4.5 pu, while without using FCL, the magnitude of fault cuent was 3 to 5 times geate than its nomal value. Table 1. Values of SMO, voltage sag and fault cuent Without FCL With FCL SMO (ad/s Inf. 4.197 Aveage Voltage Sag (% 56.8 5.71 Line 7 (pu.4667 4.77 Cuent Limitation Line 9 (pu 1.4367 4.47 VI. CONCLUSIONS In this pape, enhancement of powe system s tansient stability by using a -based FCL is poposed. The poposed -based FCL can impove the tansient stability by two ways. Fistly, by peventing the voltage sag in connected bus duing the fault and secondly by absobing the acceleation powe of geneatos in the fault inteval and stoing it in magnet. By this manne, the synchonous geneatos can keep thei stability afte the shot cicuit faults. Sum of maximum oscillations (SMO of geneatos angula fequency and aveage of voltage sag on system buses ae consideed as indices to evaluate the tansient stability and voltage pofile impovement capability of the poposed FCL. In geneal, analytical analysis and simulation esults using EMTC/PSCA softwae in standad IEEE 14-bus system show that the poposed FCL has acceptable pefomance in tansient stability enhancement and voltage pofile impovement in addition to fault cuent limiting. REFERENCES [1] M. Jafai, S.B. Nadei, M. Taafda Hagh, M. Abapou, S.H. Hosseini, Voltage Sag Compensation of Point of Common Coupling (PCC Using Fault Cuent Limite, IEEE Tansactions on Powe elivey, Vol. 6, No. 4, pp. 638-646, Octobe 11. [] M. Sedighiadeh, B. Minooie, M. Savi, Powe System Stability Enhancement Using a NSPSO esigned UPFC amping Contolle, Intenational Jounal on Technical and Physical Poblems of Engineeing (IJTPE, Issue 14, Vol. 5, No. 1, pp. 1-8, Mach 13. [4] S.B. Nadei, M. Jafai, M. Taafda Hagh, Paallel Resonance Type Fault Cuent Limite, IEEE Tans. Ind. Electon., Vol. 6, No. 7, pp. 538-546, July 13. [5] M. Mohammadi, N. Javiash, M. Pahoodeh, Stability Enhancement of FIG Wind Tubines by Paametes Tuning of FACTS evices, Intenational Jounal on Technical and Physical Poblems of Engineeing (IJTPE, Issue 14, Vol. 5, No. 1, pp. 8-88, Mach 13. [6] Y. Lin, L.L. Zhen, K.P. Juengst, Application Studies of Supeconducting Fault Cuent Limites in Electic Powe Systems, IEEE Tans. Appl. Supeconducting, Vol. 1, No. 1, Mach. [7] M. Taafda-Hagh, M. Abapou, Non-Supeconducting Fault Cuent Limite with Contolling the Magnitudes of Fault Cuents, IEEE Tans. Powe Electon., Vol. 4, No. 3, Mach 9. [8] H. Ohsaki, M. Sekino, S. Nonaka, Chaacteistics of Resistive Fault Cuent Limiting Elements Using YBCO Supeconducting Thin Film with Meande-Shaped Metal Laye, IEEE Tans. Appl. Supecond., Vol. 19, No. 3, pp. 1818-18, June 9. [9] V. Sokolovsky, V. Meeovich, I. Vajda, V. Beilin, Supeconducting FCL - esign and Application, IEEE Tans. Appl. Supecond., Vol. 14, No. 3, pp. 199-, Septembe 4. [1] S.H. Lim, H.S. Choi,.Ch. Chung, Y.H. Jeong, Y.H. Han, T.H. Sung, B.S. Han, Fault Cuent Limiting 4
Intenational Jounal on Technical and Physical Poblems of Engineeing (IJTPE, Iss. 17, Vol. 5, No. 4, ec. 13 Chaacteistics of Resistive Type SFCL Using A Tansfome, IEEE Tans. Appl. Supecond., Vol., No., pp. 55-58, June 5. [11] T. Hoshino, K.M. Salim, M. Nishikawa, I. Muta, T. Nakamua, C Reacto Effect on Bidge Type Supeconducting Fault Cuent Limite uing Load Inceasing, IEEE Tans. Appl. Supecond., Vol. 11, No. 1, pp. 1944-1947, Mach 1. [1] M. Taafda-Hagh, M. Abapou, Non-Supeconducting Fault Cuent Limites, Euo. Tans. Elect. Powe, Vol. 19, No. 5, pp. 669-68, July 9. [13] G.T. Son, H.J. Lee, S.Y. Lee, J.W. Pak, A Study on the iect Stability Analysis of Multi-Machine Powe System with Resistive SFCL, IEEE Tans. Appl. Supeconduct., Vol., No. 3, Aticle No. 5634, June 1. [14] I. Ngamoo, S. Vachiasiciikul, Coodinated Contol of Optimied SFCL and fo Impovement of Powe System Tansient Stability, IEEE Tans. Appl. Supeconduct., Vol., No. 3, Aticle No. 5685, June 1. [] M. Feie, Enegy Stoage in a Supeconducting Winding in Low Tempeatue and Electic Powe, Pegamon Pess, pp. 45-43, 197. [16] J.. Roges, 3-MJ System fo Electic Utility Tansmission Stabiliation, Poc. IEEE, Vol. 71, pp. 19-117, 1983. [17] R.J. Loyd, S.M. Schoenung, T. Nakamua, W. Hassenahl, J.. Roges, J.R. Hcell,.W. Lieuance, M.A. Hilal, esign Advances in Supeconducting Magnetic Enegy Stoage fo Electic Utility Load Leveling, IEEE Tans. Mag., Vol. 3, pp. 133-133, 1987. [18] F. Fattahi, N.M. Tabatabaei, N. Taghiadegan, amping of Oscillations of Aebaijan Electical Netwok by System and Fuy Contolle, Intenational Jounal on Technical and Physical Poblems of Engineeing (IJTPE, Issue, Vol., No. 1, pp. 11-14, Mach 1. [19] A. Jalili, H. Shayeghi, N.M. Tabatabaei, Fuy PI Contolle Based on LFC in the eegulated Powe System Including, Intenational Jounal on Technical and Physical Poblems of Engineeing (IJTPE, Issue 8, Vol. 3, No.3, pp. 38-47, Septembe 11. [] E.R. Lee, S. Lee, C. Lee, H.J. Suh,.K. Bae, H.M. Kim, Y.S. Yoon, T.K. Ko, Test of C Reacto Type Fault Cuent Limite Using Magnet fo Optimal esign, IEEE Tans. Appl. Supecond., Vol. 1, No., pp. 85-853, Mach. [1] I. Ngamoo, S. Vachiasiciikul, Optimied SFCL and Units fo Multi-Machine Tansient Stabiliation Based on Kinetic Enegy Contol, IEEE Tans. Appl. Supeconduct., Vol. 3, No. 3, Aticle No. 539, June 13. [] M. Jafai, A. Vafameh, M.R. Aliadeh Pahlavani, Tansient Stability Enhancement Using -Based Fault Cuent Limite, Intenational Review of Automatic Contol (IREACO, Vol. 5, No. 6, pp. 749-756, Novembe 1. [3] G. idie, J. Leveque, A. Reoug, A Novel Appoach to etemine the Optimal Location of SFCL in Electic Powe Gid to Impove Powe System Stability, IEEE Tans. Powe Sys., Vol. 8, No., pp. 978-984, May 13. [4] Y. Shiai, K. Fuushiba, Y. Shouno, M. Shiotsu, T. Nitta, Impovement of Powe System Stability by Use of Supeconducting Fault Cuent Limite with ZnO evice and Resisto in Paallel, IEEE Tans. Appl. Supecond., Vol. 18, No., pp. 68-683, June 8. [5] K. Fuushiba, T. Yoshii, Y. Shiai, K. Fushiki, J. Baba T. Nitta, Powe System Chaacteistics of the SCFCL in Paallel with A Resisto in Seies with A ZnO evice, IEEE Tans. Appl. Supecond., Vol. 17, No., pp. 19-1918, June 7. [6] B.Ch. Sung,.K. Pak, J.W. Pak, T.K. Ko, Study on a Seies Resistive SFCL to Impove Powe System Tansient Stability - Modeling, Simulation and Expeimental Veification, IEEE Tans. Ind. Electon., Vol. 56, No. 7, pp. 41-419, July 9. [7] B.Ch. Sung, J.W. Pak, Optimal Paamete Selection of Resistive SFCL Applied to A Powe System Using Eigenvalue Analysis, IEEE Tans. Appl. Supecond., Vol., No. 3, pp. 1147-1, June 1. BIOGRAPHIES Mehdi Jafai was bon in Aha, Ian. He eceived the B.Sc. and M.Sc. degees in Powe Engineeing fom Univesity of Tabi, Tabi, Ian, in 8 and 11, espectively. He is cuently with the Aha Banch, Islamic Aad Univesity, Aha, Ian. His cuent eseach inteests include fault cuent limites, powe quality and powe system tansient. Mohammad Rea Aliadeh Pahlavani eceived the Ph.. degee in Electical Engineeing fom Ian Univesity of Science and Technology, Tehan, Ian in 9. Cuently he is in epatment of Electical Engineeing, Malek Ashta Univesity of Technology, Tehan, Ian. He is the autho of moe than 11 ISI tansactions jounals, intenational, and national confeence papes in the field of electomagnetic systems, electical machines, powe electonic, FACTS and pulsed powe. 41