Weak bus-oriented optimal Var planning based on grey wolf optimization

From last few decades, the frequent occurrence of the voltage collapse has attracted more and more attention. Voltage collapse is the system instability, usually, associated with the shortage of reactive power at the load end involving the entire power systems. The most effective method to counter voltage collapse is to find out the possible locations where voltage collapse may occur i.e. to find the weakest buses existing in the system. Weak bus oriented Var planning by grey wolf optimization (GWO) for system security has been proposed in this paper. Weak buses of the system has been determined by using four different methods, namely, fast voltage stability index (FVSI), line stability factor (LSF), line stability index (LSI) and voltage collapse proximity indicator (VCPI) method. Standard IEEE 57 bus test system is used as the test system to show the applicability of the proposed work. It has been observed that Var planning based on the detection of weak buses by voltage collapse proximity indicator provides the best result among other methods reported in literature.