IEEE --- 2005 Initernationtal Coniferetnce on Emiierging Technologies Septemnber 17-1S, Islaminabad Network Simulation with STATCON Devices to avoid Voltage Collapse in the Interconnected System Mohaimnad Ahmad Choudhry KashifNaeem Bangash Tahir Mahrnood Dept. of Electrical Engineering University of Engineering & Technology Taxila drahrmad(duettaxila.edu.pk conductors themselves and the geometry of the conductor configuration. Abstract In this paper r-eactive power control with the help of STA TCON ha1s been si/nzilaCted. Converter operation an?d switchinsg sequtence hcis been bhriefd. Real dctaci of' Wcapdai 500/220 k V pow?ier svstem retagarding extreme calses ol voltacge control hais been simulilcited on7 power system simulator PSS/E. Difljrent ralItin)g of simuiitlcited STA TCON has heen sugIgested Cat various stations to ov'ercomne voltcige collapse problem7t, increase steady, staite, Cdynanfic cand transient stability. 1. Introduction In moving power from generator to loads, the transmission network introduces both real and reactive losses. Real or active power transfer depends mainly on the power angle. Reactive power transfer depends mainly on voltage magnitude and flows from higlhest voltage to the lowest voltage. Tlle reactive-power nature of transmission lines is associated vith the geometry of the Contrasted with real power, reactive power simply cannot be transmitted long distances. To minimize reactive losses transfer of reactive power must be minimized and possible reactive power slhould be generated close to the point of consumption. Transmission lines both produce and consume reactive power. Transmission line shunt capacitance produces reactive power proportional to the square of voltage. Transmission line series inductance consumes reactive power proportional to the square of current. The reactive-power behavior of transmission lines is complicated by their inductive and capacitive characteristics. At low line loadings, the capacitive effect dominates, and generators and transmission- related reactive equipment must absorb reactive power to maintain line voltages within their appropriate limits. On the other hand, at high line loadings, the inductive effect dominates, and generators, capacitors, and other reactive devices must produce reactive power. The balance point at which the inductive and capacitive effects cancel each other (what is called surge-impedance 0-7803-9247-7/05/$20. 00 ©2005 IEEE 412