Strategic Capacitor Placement for Reducing Voltage Collapse Probability in Power Systems

Bus voltage stability is very important factor in power system reliability.Voltage instability and protection system malfunction can lead to voltage collapse. If power systems cannot meet reactive power demands on a bus, voltage starts to drop. Thus, reactive power compensation can reduce the risk of voltage collapse. In this paper, two new indices are introduced for weak bus identification; also, a method is proposed for reducing the collapse probability of placing capacitors. To this end, the networks of 30 IEEE standard buses were studied; buses were ranked according to the weakest bus identification indices. Network probabilities of being in normal, under-voltage, and risk-and-collapse zones were calculated. By the strategic placement of capacitors with PSO (Particle swarm optimization), the algorithm probability of networks in the collapse zone reduced significantly; also, the performance of proposed indices over other methods was illustrated.