Optimal reactive power planning against voltage collapse using the successive multiobjective fuzzy LP technique

A new and comprehensive method for optimal reactive power planning (ORPP) against voltage collapse (VC) is given. The problem has the objectives of optimally siting and sizing new capacitors at prospective locations such that the transmission loss is minimum, an acceptable voltage profile is obtained, and the voltage stability is improved. To plan against VC, modal analysis is used to generate a participation-factor-based voltage collapse sensitive index (VCSI). VCSI is used to rank and select the best few prospective buses to site new capacitors. Using fuzzy models, all the violated load bus voltage constraints are fuzzified and their enforcements are maximised. The nonlinear programming problem of ORPP is solved in the successive multiobjective fuzzy LP framework. The proposed method was tested on modified IEEE 6-bus system and on a 191-bus Indian electric utility system. The results of the studies are discussed