Optimization of Shunt Compensation for Voltage Stability Improvement Using PSO

Abstract

Voltage instability mainly occurs due to domination of lagging loads present in power system; because of voltage instability, power system faces some difficulties. Some effective methods are discussed in order to improve voltage stability. FVSI is effective method that investigates stability of the each line. FVSI indices are calculated for all lines, and these values ranked according to vulnerable to voltage instability. Load bus connected to vulnerable line treated as vulnerable bus and reactive power is injected at that bus and that is optimal location for compensation; this process can be done for different contingencies and optimal size can be determined by PSO. Implementing PSO to the IEEE 14-bus test system optimal location and size of the shunt compensation is found by finding that the search space considering the FVSI indices values by making the FVSI having highest values will be the vulnerable buses, by implementing the PSO iteratively and by randomly updating the reactive power values at each candidate solution. In each iteration, reactive power injection is found at each candidate and checked for the closeness to the desired solution. These local best values are updated depending upon the fitness values as per the found values. After each iteration, pbest values will be updated with the global best values and are called the Gbest. This Gbest will be considered as the final solution for the placement of shunt compensation at those candidate spaces.