Two Methods for Capacitor Placement Optimization Based on Improved Genetic Algorithm

An improved genetic algorithm for capacitor placement optimization is presented and applied in distribution system.The algorithm considers the location and capability of the capacitor to be installed as discrete variables.The minimization of the sum of various costs,including purchasing cost,installation cost,maintenance cost and active power loss charge,is regarded as objective function.Two methods for solving this optimization problem are provided.The first one needs to determine the locations and the maximal bank sizes under the maximal load level,and then calculates the precise bank sizes of fixed capacitor with other load levels,thus the total income is determined.Differing from the former method,the other method determines the sizes of fixed capacitor banks under the minimal load level first,and then calculates the sizes of switched capacitor banks with other load level.Compared with the simple genetic algorithm,the presented algorithm makes improvements on coding,selection,crossover,mutation and termination condition during the process of evolution.Finally,a reasonable result is shown obtained by the proposed methods in a 27-bus distribution system.