172 REFERENCES [1] Kundur P., “P.S. Stability and Control”, McGraw- Hill, Inc., 1994. [2] J.P. Charpentier, Sharma R and Rudervall R, “HVDC Tr. Sys Technology Review Paper”. [3] John P and Kundur P., “Definition and Classification of P.S. Stability”, IEEE Trans. on Power Systems., pp:1387- 1401, Vol. 19, No. 2, May 2004. [4] R. Zhang, Y. Min, Q. Tu and K. Hou, “A new method for generation shedding and load shedding in emergency control of P.S.,” in Proc. IEEE International Conference on Electric Utility Deregulation, Restructuring and Power Technologies, April 2K4, vol. 1, pp: 210– 214. [5] X. Chen, Y. Sun, C. Li and C. Deng, “An on-line transient stability emergency control strategy based on PMU forecasted trajectory,” in Proc. Int. P.Engg Conference, pp. 807–812, Dec 2K7. [6] Pavella M. and Vega D.R. , “A comprehensive approach to transient stability control. II. open loop emergency control,” IEEE Trans Power System, no. 4, vol. 18, pp. 1454–1460, Nov 2K3. [7] Pavella M., D. Ernst, “Closed-loop transient stability emergency control”, Proc. IEEE Power Engineering Society Winter Meeting, vol. 1, pp. 58–62, 2K. 173 [8] D. Ruiz-Vega, D. Ernst, M. Glavic, L. Wehenkel and M. Pavella, “ESIME - a method for transient stability closed-loop emergency control: achievements and prospects”, in Proc. IREP Symposium- Bulk Power System Dynamics and Control - VII, Revitalizing Operational Reliability, pp. 1–10, Aug 2K7. [9] T. S. Bhatti, R. Patel and D. P. Kothari, “A modified approach to transient stability enhancement with fast valving and braking resistor applications”, Int. J Electrical Power & Energy Systems, no. 10, vol. 28, Dec 2K6, pp. 729–738. [10] R. Ramshaw and N. Fernandopulle , “Domain of stability of a synchronous machine with excitation control-a cell mapping approach”, Electric Power Systems Research, pp. 173–181, no. 3, vol. 27, Aug 1993. [11] Rao N.R. and Reitan D.K., “A method of improving transient stability by bang-bang control of tie-line reactance”, IEEE Trans Power Apparatus and Systems, no. 1, vol. PAS-93, Jan 1974, pp. 303–311. [12] Gyugyi L., ‘Unified power-flow control concept for flexible AC transmission systems”, IEE Proc., Part-C, No. 4, Vol. 139, pp. 323331, 1992. [13] Zhou E.Z., “Application of SVAR compensators to increase P.S. damping”, IEEE Trans. of Power Systems, pp. 655-661, No. 2, Vol. 8, 1993. 174 [14] D. Povh, P. Zunko, R. Mihalic and I. Papic, “Improvement of transient stability by insertion of FACTS devices”, Proc. of the Power Tech, pp. 521-525, Sept. 5-8, 1993. [15] J. Samuelsson, L. Angquist and B. Lundin, “Power oscillation damping using controlled reactive power compensation – A comparison between series and shunt approaches”, IEEE Trans. on PS, pp. 687-695, Vol. 8, No. 2, 1993. [16] G. Andersson, L. Angqist, M. Noroozian and M. Ghandhari, “Improving power system dynamics by series connected FACTS devices”, IEEE Trans. of PD, pp. 1635-1641, Vol. 12, No. 4, 1997. [17] Pahalawaththa N.C., S. Limyingcharoen and U. D. Annakkage , “Fuzzy logic based unified power flow controllers for transient stability improvement” , IEE Proc-Gener. Trans. Distrib., No. 3, Vol. 145, May 1998. [18] L. Gyugyi and N.G. Hingorani, “Understanding FACTS: Concepts and technology of flexible ac transmission systems”, Edn.1999, IEEE Press, NY. [19] M. Kato, Y. Morioka, Y. Nakachi and Y. Mishima, “Implementation of unified power flow controller and verification for transmission capability improvement”, IEEE Trans. on PS, pp 575-581, 1999, Vol. 14, No. 2. 175 [20] J. Gronquist, M. Ghandhari, M. Noroozian, I. Hiskens and G. Anderson, “A robust control strategy for shunt and series reactive compensators to damp electromechanical oscillations”, IEEE Trans. on PD, , pp. 812-817, Vol. 16, No. 4, 2K1. [21] Rasolomampionona D.D., S. Robak and M. Januszewski , “P.S. stability enhancement using PSS and UPFC Lyapunov-based controllers: A comparative study”, Proc. of the Bologna Power Tech Conference, June 23-26, 2K3. [22] M.H. Haque and P. Kumkratug , “Improving of stability region and damping of a P.S. by using SSSC”, Proc. of the IEEE PES , 13-19 July 2K3. [23] Haque M.H., “Improvement of fist swing stability limit by utilizing full benefit of shunt FACTS devices”, IEEE Trans. on PS, 2K4, Vol. 19, No. 4, pp. 1894-1902. [24] Haque M.H., “Stability improvement by FACTS devices: A comparison between STATCOM and SSSC”, Proc. of the IEEE PES, 1316 July 2K5. [25] S. Saadate and E. Gholipour, “Improving of transient stability of power systems using UPFC”, IEEE Trans. on PD, pp.1677-1682, Vol. 20, No. 2, 2K5. [26] Mishra S, “Neural-Network-Based Adaptive UPFC for Improving Transient Stability Performance of Power System”, IEEE TRANSACTIONS ON NEURAL NETWORKS, NO. 2, VOL. 17, MARCH 2K6. 176 [27] Haque M. H., “Application of UPFC to Enhance Transient Stability Limit”, IEEE 2K7. [28] L. Gyugyi and N. G. Hingorani, “Understanding FACTS: Concepts and Technology of Flexible AC Transmission Systems”, 1999 edn, Wiley-IEEE Press. [29] A.H.M.A. Rahim and I.M. El-Amin , “STABILIZATION OF A HIGH VOLTAGE AC-DC POWER SYSTEM II. MULTIMACHINE SYSTEM SUBJECTED TO LARGE PERTURBATION”, IEEE Transactions on Power Apparatus and Systems, No. 11, Vol. PAS-104, November 1985. [30] D. Mc Callum, J.Gagnon and A.E. Hammad, “IMPROVING THE DYNAMIC PERFORMANCE OF A COMPLEX AC/DC SYSTEM BY HVDC CONTROL MODIFICATIONS”, IEEE Transactions on Power Delivery, November 1990, Vol. 5, No. 4. [31] Teshome A., “Effect of a modulated HVDC link on power system transients”, Electric Power System Research, pp. 101–109, vol. 25, no. 2, Nov 1992. [32] M.A. Choudhry and S.M. Badran, “DESIGN OF MODULATION CONTROLLERS FOR AC-DC P.Ss”, IEEE Transactions on Power System, November 1993, Vol. 8, No. 4. [33] S. P. Cheung, S. K. Tso, “Fast prediction of transient stability margin in systems with SVC control and HVDC link”, Proc. Int. Conf. Energy Management and Power Delivery, vol. 2, pp. 456–461, Nov 1995. 177 [34] M. Goto, K. Yamaji, K. Tomiyama, M. Sato and M. Sekita, “Power swing damping control by HVDC power modulation in an AC-DC hybrid transmission system”, Electrical Engineering in Japan, pp. 10– 18, vol. 124, no. 3, Dec 1998. [35] Jovcic Dragan, “ Control of HVDC Systems operating with long DC cables”, IEE AC-DC Power Transmission , 2K1 Nov. [36]Ngamroo I., “A Stabilization of Frequency Oscillations using a Power Modulation Control of HVDC Link in a Parallel AC-DC Interconnected System”, pp: 1405-1410, 2K2 IEEE. [37] Z. Yao and M. Xiao-ming, “Application of HVDC modulation in damping electromechanical oscillations”, in Proc. IEEE PESGeneral Meeting, pp. 1–6, June 2K7. [38] Krause P.C. and Peterson H.A, “Damping of power swings in a parallel AC and DC system”, IEEE Trans. PAS., (December 1966), pp. 1231-1239, Vol. 85. [39] PAUL C. KRAUSE and DENNIS P. CARROLL , “Stability Analysis of a DC Power System”, IEEE TRANS on PAS, NO. 6, VOL. PAS-89, JULY/AUGUST 1970. [40] N. G. Hingorani, J. L. Hay and J. S. Bhatti , “SIMPLIFIED DYNAMIC SIMULATION OF HVDC SYSTEM BY DIGITAL COMPUTER: PART II- DESIGN OF CONTROLLER AND TEST RESULTS”, IEEE TRANSACTIONS ON POWER APPARATUS MARCH/APRIL 1971, NO. 2, VOL. PAS-90. AND SYSTEMS, 178 [41] Mittelstadt W.A. and Cresap R.L, “Small-signal modulation of the Pacific HVDC Intertie”, IEEE Trans. PAS., pp.536-541, Vol. 95 (March/April 1976). [42] Krishna C.R., Pai M. A. and Padiyar K. R., “TRANSIENT STABILITY ANALYSIS OF MULTI-MACHINE AC/DC POWER SYSTEMS VIA ENERGY-FUNCTION METHOD”, IEEE Transactions on Power Apparatus and Systems, December 1981, No. 12, Vol. PAS-100. [43] Krishna A.C.R., Padiyar K.R. and Pai M.A., "A versatile system model for the dynamic stability analysis of power systems including HVDC links”, IEEE Trans. PAS., pp:1871-1880, Vol. 100 (April 1981) . [44] Decarlo R.A., Lefebvre S and Carroll D.P., “Decentralized power modulation of multiterminal HVDC systems”, IEEE Trans. PAS., (July 1981), pp.3331- 3339, Vol. 100 . [45] R.W. Menzies, D.A. Woodford and A.M. Gole , “DIGITAL SIMULATION OF DC LINKS AND AC MACHINES”, IEEE Transactions on Power Apparatus and Systems, No. 6, Vol. PAS-102, June 1983. [46] J. Arrilaga and K.S. Turner, “HVDC CONTROL STRATEGIES TO IMPROVE TRANSIENT STABILITY IN THE INTERCONNECTED P.Ss”, IEEE Transactions on Power Apparatus and Systems, No. 7, Vol. PAS-102, July 1983. [47] Carroll reactive D. P. and Chowdary M.A, “Coordinated active and power modulation of multiterminal HVDC Trans. PAS., pp 1480-1485, Vol. 103 (June 1984). systems”, IEEE 179 [48] E. Salgado, “UNCONVENTIONAL M. Szechtman, HVDC J.P. Bowles, CONTROL W.W. TECHNIQUE Ping, FOR STABILIZATION OF A WEAK POWER SYSTEM”,IEEE Transaction on Power Apparatus and Systems, August 1984, Vol. PAS-103, No. 8. [49] Woodford D.A., “VALIDATION OF DIGITAL SIMULATION OF DC LINKS”, IEEE Transactions on Power Apparatus and Systems, Vol. PAS-104, , September 1985, No. 9. [50] Nejad A.H. and Ong C. M., “DIGITAL SIMULATION OF MULTITERMINAL HVDC SYSTEMS FOR TRANSIENT STABILITY STUDIES USING A SIMPLIFIED DC SYSTEM REPRESENTATION”, IEEE Transactions on Power Apparatus and Systems, June 1985, Vol. PAS-104, No. 6. [51] M.A. Choudhry and K.A. Kllithy , “EFFECT OF LOAD MODELS ON AC/DC SYSTEM STABILITY AND MODUI.ATION CONTROL DESIGN”, IEEE Transactions on Power Systems, No. 2, Vol. 4, May 1989. [52] A.R. Saavedra, A.R. Wood and J. Arrillaga, “Unified control strategy for back-to-back HVDC convertor stations”, IEE PROCEEDINGS-C, No.2, MARCH 1993, Vol. 140. [53] Kacejko P. A., Yeo R. L., Hammons T. J. and Gwee C. L., "Enhancement of power system transient response by control of HVDC converter power", Electric Machines and Power Systems, pp. 219-41, vol. 28, Mar. 2K. 180 [54] Liu Z., "Design features of Three Gorges-Changzhou ±500 kV HVDC Project", in Proceedings of the IEEE PES Winter Meeting, pp. 12-16, 2K. [55] Samuelsson O., "Load modulation at two locations for damping of electro-mechanical oscillations in a multi machine system”, in Proceedings of the PES Summer Meeting, pp. 1912-17, 2K. [56] X. Qiu, X. Li, H. Liu et al, “A nonlinear control strategy of HVDC for improving transient stability of P.Ss”, Automation of Electric Power Systems, pp. 16-19, vol. 26, 2K2. [57] Ngamroo I, “A Stabilization of Frequency Oscillations in a Parallel AC-DC Interconnected Power System via an HVDC Link”, 173-180, Science Asia 28 (2K2) . [58] I. Ngamroo, S. Dechanupapritfha and A. Patanapakdee, “AN HVDC-BASED CONTROLLER DESIGN FOR STABILIZATION OF FREQUENCY OSCILLATION”, pp: 379-382, 2K3 IEEE. [59] Lu Jiming, Hu Zhaoqing and Mao Chengxiong, “A NOVEL CONTROL STRATEGY FOR VSC BASED HVDC IN MULTI-MACHINE P.Ss”, JOURNAL OF ELECTRICAL & ELECTRONICS ENGINEERING, 2K4, pp: 1183-1190, Vol 4, No 2. [60] Khan B.H. and Rahman H., “Stability improvement of power system by simultaneous AC–DC power transmission”, Electric Power Systems Research, pp.756–764, 78 (2K8). 181 [61] Daehler P., Hammad A. and Koelsch H., “ACTIVE AND REACTIVE POWER CONTROLS FOR THE GEZHOUBA-SHANGHAI HVDC TRANSMISSION SCHEME”, Switzerland, ABB Power Systems. [62]IEEE committee report,“HVDC Controls for System Dynamic Perfo rmance”, IEEE Trans., pp. 743‐752, Vol. PWRS‐6, No. 2, May 1991. [63] B. Johnson, W. Wong, S. Lefebvre, J. Reeve and J. Gagnon , “ExperiencewithModeling MTDC Systems in Transient StabilityProgra ms,” IEEE Trans.on PD, pp. 405‐413, Vol. 6, No. 1, Jan 91. [64] IEEE committee report, “Dynamic Performance Characteristics of North American HVDC Systems Stability Evaluations,” IEEE Trans. for Transient On and Dynamic PAS, No. 7, Vol. PAS‐100, July 1981, pp. 3356‐3364. [65] Padiyar K. R., “HVDC Power Transmission Systems”, 2K4 edn, New Age International (P) Ltd. [66] “IEEE Guide for Planning DC Links Terminating at AC Locations Having Low Short-Circuit Capacities”, 1997 edn,The Institute of Electrical and Electronics Engineers, Inc. [67] Wang L. and Hsu Y.Y., “Damping of a parallel ac-dc power system using PID power system stabilizers and rectifier current regulators”, IEEE Trans. On Energy Conversion, September 1988, vol. 3, no. 3, pp. 540-547. 182 [68] G.S. Hope, B. Puthal, P. K. Dash and 0.P. Malik, “TRANSIENT STABILITY AND OPTIMAL CONTROL OF PARALLEL AC-DC P.Ss”, IEEE Transactions on Power Apparatus and Systems, no.3, Vol. PAS-95, May/June 1976. [69] A. Prole and V. P. Lukic, “Optimal connection of controlled HVDC to AC power system”, Electrical Power & Energy Systems , Edn.1984. [70] M.A. Choudhry, G.D. Galanos and A.S. Emarah, “Design of Optimal Modulation Controllers for Multi- area using Eigen value sensitivities”, IEEE Trans. AC/DC Systems Power System, August 1987, pp. 522-528, vol. PWRS-2, no. 3. [71] EL-AMIN IBRAHIM, “An Optimal Control Strategy for MultiTerminal HVDC Systems”, JKAU: Eng. Sci., pp. 31-50 2K2, vol. 14 no. 2. [72] Marc T., Ula S. and Pecen R., “Modeling and simulation of a Kalman Filter based control scheme for an AC/DC P.S.”, Electrical Power and Energy Systems, 173–189, 26 (2K4). [73] A.C. Liew, A. Controllers for Routray and P.K. Dash, “High performance HVDC Transmission Links”, IEE Proc. Gener. Transm. Distrib., September 1994, pp. 422-428, vol.141, no. 5. [74] A.K. David, A.F. Hammad and K.W.V. To, “A robust co-ordinated control scheme for HVDC transmission with parallel ac systems”, IEEE Trans. Power Delivery, July 1994, pp. 1710-1716, vol. 9, no. 3. 183 [75] A. Routray, A.C. Liew and P.K. Dash, “Design controllers for HVDC links in of AC-DC P.Ss” ,Electric robust Power Systems Research , pp:201-209, vol 33 (1995). [76] V. Vittal, S. Venkataraman and M.H. Khammash, “ANALYSIS AND SYNTHESIS OF HVDC CONTROLS FOR ROBUST STABILITY OF POWER SYSTEMS”, IEEE Transactions on Power System, November 1995, Vol. 10. No. 4. [77] G. Anderson and L. E. Jones, “SELECTING ROBUST INPUT SIGNALS FOR HVDC DAMPING CONTROLLERS”, AC and DC Power Transmission, 1996, April- May. [78] H. Werner and M. Aten, “Robust multivariable control design for HVDC back-to back schemes”, IEE Proc-Gen. Trans. Distr., No. 6, Vol 150, November 2K3. [79] Ula S, Timmerman M. and Recayi P, “Modeling and simulation of a Kalman filter based control scheme for an AC/DC P.S.”, Int. J. Elect Power Energy Sys 2K4 [March], 26(3):173–189. [80] R. HURTEAU, M. SAAD and S. LEFEBVRE, “ADAPTIVE CONTROL FOR HVdc POWER TRANSMISSION SYSTEMS”, IEEE Transactions on Power Apparatus and Systems, September 1985, Vol. PAS-104, No. 9. [81] J.S. Thorp, A.G. Phadke, N. Rostamkolai and W.F. Long, “AN ADAPTIVE OPTIMAL CONTROL STRATEGY FOR DYNAMIC STABILITY ENHANCEMENT OF AC/DC POWER SYSTEMS”, IEEE Transactions on Power Systems, August 1988, Vol. 3, No. 3. 184 [82] Mansour S. and Reeve J., “Gain scheduling adaptive control strategies for HVDC systems to accommodate large disturbances”, IEEE Trans Power Sys 1994, 366–372 [February], 9(1). [83] A.K. David and K.W.V.To, “Multivariable adaptive control of ACDC systems”, IEE, pp: 658-664, 1994. [84] Ula A.H.M.S. and Meah K. , “A new simplified adaptive control scheme for multi-terminal HVDC transmission systems”, (2K9), Electrical Power and Energy Systems. [85] P.K. Kalra, “On Development of Expert Systems for HVDC Controls”, Proceedings of 2nd Conference on Engineering Problems, 1986. [86] Kalra, P.K. and Emmanuel P., “Requirements for the Development of an Expert System for HVDC Controls”, published in Symposium on Expert System application in Power System, Sweden, 1988, pp 6.226.25. [87] B.K. Bose, “Expert system, fuzzy logic, and neural network applications in power electronics and motion control”, Proceedings of the IEEE: Aug 1994, pp: 1303 – 1323, Vol 82 Issue: 8. 185 [88] Jignesh Solanki, Noel Schulz and Sarika Khushalani, “Optimized restoration of combined ac/dc shipboard power systems including distributed generation and islanding techniques”, Electric Power Systems Research, Pages 1528-1536, Volume 78, Issue 9, September 2K8. [89] K. Khorasani, V. K. Sood, R. V. Patel and N. Kandil, “Comparative Evaluation of Neural-Network-Based and PI Current Controllers for HVDC Transmission”, IEEE TRANSACTIONS ON POWER ELECTRONICS, MAY 1994, VOL. 9 , NO. 3. [90] K. Khorasani, V. K. Sood, K. G. Narendra and R. V. Patel, “Investigation into an Artificial Neural Network based On-Line Current Controller for an HVDC Transmission link”, IEEE Transactions on Power Systems, No. 4, Vol. 12, November 1997. [91] R.V.Pate1, K.Khorasani, K.G. Narendra and V.K. Sood, “Intelligent Current Controller for an HVDC Transmission link”, IEEE Transactions on Power Systems, No. 3, Vol. 13, August 1998. [92] S. Filizadeh, A. M. Gole and E. Rahimi “Commutation Failure Analysis in HVDC Systems Using Advanced Multiple-Run Methods”, International Conference on Power Systems Transients (IPST’05), June 19-23, 2K5. 186 [93] Y.A. Mubarak, “Genetic Algorithms Controllers for HVDC Systems Control”, pp:477 – 481, Proceedings of the 41st International Universities Power Engineering Conference, UPEC’ 2K6. [94] Kumar S.V.J.R. and Srujana A., “A Novel HVDC Control Strategy to Enhance Interconnected Power Systems: A Graphical-Based Solution”, American Journal of Scientific Research, pp.35-46, Issue 11(2K10). [95] Parthasarathy K, Purushothama GK, Thukaram D. and Udupa AN, “A fuzzy control for network overload alleviation”. Int J Elect Power Energy Sys 2K1; 119–28 [February], 23(2). [96] Hui R., Mok TK, Liu H, Ni Y and Wu FF, “Tuning the fuzzy damping controller for UPFC through genetic algorithm with comparison to the gradient descent training”, Int J Elect Power Energy Sys 2K5; 275–83 [May], 27(4). [97] S.Rahman, P.K.Dash and A.Routray, “AN ADAPTIVE FUZZY LOGIC CONTROLLER FOR AC-DC POWER SYSTEMS “, IEEE 1993. [98] Liew AC, Dash PK and Routray A., “High-performance controller for HVDC transmission links”, IEE Proc Generation Transmission Distribution 1994; 422–428[September], 141(5). [99] Panda SK., Dash PK and Routray A, “A fuzzy self-tuning PI controller for HVDC links”. IEEE Trans Power Elect 1996; 669–79 [September], 11(5). 187 [100] Davies JB, Gole AM, Chapman DG and Daneshpooy A , “Fuzzy logic control for HVDC transmission”, IEEE Trans Power Delivery, 1997;pp.1690–1697 [October], 12(4). [101] H.J.C.Peiris, U.D. Annakkage and N.C. Pahalawaththa, “Damping improvement of an ac-dc interconnected system using a fuzzy logic coordinated modulation controller”, IEEE 1998. [102] Kang H.T., Park J.H., Choi J.G. and Hwang G.H., “DESIGN OF FUZZY LOGIC CONTROLLER FOR HVDC USING AN ADAPTIVE EVOLUTIONARY ALGORITHM”, 2K1 IEEE ISIE. [103] F. D. Zhong and T. S. Chung , “Fuzzy logic controller for enhancing oscillatory stability of AC/DC interconnected power system,” Elect. Power Syst. Res., pp. 221–226, vol. 63, no. 3, 2K2. [104] K. Kantapanit, C. Treesatayapun, and S. Dumronggittigule, “HVDC control system based on Fuzzified Input Perceptron”, IEEE Bologna power Tech Conference ,June 2K3. [105] Jahed Motlagh MR, Najafi HR, Shoulaie A, and Robinson F, “A new self-tuning robust PI controller for HVDC systems”. 39th International universities power engineering conference, UPEC 2K4, pp. 698–703, vol. 2. [106] Meah K, Ula S., “Investigation on fuzzy logic based auto-tuning current controller application in HVDC Links”, pp. 266–272, 20–22 April 2K7. 188 [107] Meah K, Ula AHMS, “Simple fuzzy self-tuning PI controller for multi-terminal HVDC transmission systems”, Elect Power Component Sys 2K8; 224–238 [March], 36(3). [108] R.K. Pandey , Arindam Ghosh, “Design of self-tuning controllers for a two terminal HVDC link”, Electrical Power and Energy Systems , 389–395, vol. 31 (2K9). [109] Stagg and El- Abiad, “Computer Methods in Power System Analysis”, International Student Edition, McGraw- Hill, Book Company, 1968 edn. [110] G.Fahny, N. Stott and J. Reeve , “VERSATILE LOAD FLOW METHOD FOR MULTITERMINAL HVDC SYSTEMS”, IEEE Trans. on PAS, no.3, May/June 1977, Vol. PAS-96. [111] B.R. Oswald and A. Panosyan, “Modified Newton-Raphson Load Flow Analysis for Integrated AC/DC Power Systems”. [112] G. Anderson and T. Smed, “A New Approach to AC/DC Power Flow”, IEEE Trans. on Power Systems., No. 3, pp 1238- 1244, Vol. 6, Aug. 1991. [113] Bruce Smith and Jos Arrillaga , “AC- DC Power System Analysis”, The Institution of Electrical Engineers, Edn.1998. [114] A. F. A. Kadir and M. W. Mustafa, "A modified approach for load flow analysis of integrated AC-DC power systems," in 2K TENCON Proceedings, pp. 108-113, Intelligent Systems and Technologies for the New Millennium. 189 [115] G. Balzer and J. Warnking, “Load-flow conditions for HVDC transmission in synchronous networks”, European Transactions on Electrical Power, Mar. 2K, vol. 10, pp. 87-91. [116] A.A. Fouad and P.M. Anderson, “Power System Control and Stability”, Iowa State University Press,1977, edn.1. [117] Vikram Krishnaswamy and Garng M. Huang, “HVDC Controls for Power System Stability”, IEEE Power Engineering Society, 2K2, pp. 597- 602. [118] G. S. Hope, M. A. M. Hassan and O.P. Malik , “A Fuzzy Logic Based Stabilizer for A Synchronous Machine”, IEEE Trans. on Energy Conversion, pp. 407- 413, Vol. 6, No. 3, September 1991. [119] Hiyama T. and Lim C.M., “Application of A Rule-Based Control Scheme for Stability Enhancement of Power Systems”, IEEE 1995, pp. 1347- 1357. [120] Cheng C.H., and Hsu Y.Y., “Design of fuzzy power system stabilizers for multi-machine power systems”, IEE Proceedings, May 1990, Vol. 137, No. 3.