Optimal reactive power planning method enhancing voltage stability margin using successive multiobjective fuzzy LP method

Lack of adequate reactive power support in a transmission system limits the real power transfer capacities leading to low voltages and Voltage Collaps e (VC) at load centers. This paper presents a Successive Multiobjective Fuz zy LP (SM-FLP) method to optimally site and size shunt capacitors such that the cost of the newly sited capacitors is minimum, the real power transmis sion loss is minimum, and the Voltage Stability Margin (VSM) is maximum whi le-obtaining the utmost satisfaction of all the violated load bus voltage c onstraints. The SMFLP method uses the Successive LP (SLP) framework to succ essively linearize the Nonlinear Programming (NLP) problem of Optimal React ive Pourer Planning (ORPP) and uses the Multiobjective Fuzzy LP (MFLP) tech nique to solve the linearized LP problems. Singular values of the Load flow Jacobian based Index: (SLJI) is used to rank and select the best prospecti ve sites for siting shunt capacitors. A set of few feast singular values of the load flow Jacobian is used as VSM indicator. This set is expressed in terms of the control vector and is optimized to maximize VSM in the propose d method. The SMFLP method of ORPP was tested upon 6 and 57 bus IEEE test s ystems. The results of the studies am presented showing the effect of ORPP on the singular values of the load flow Jacobian.