Optimal feeder reconfiguration for loss reduction by robust searching hybrid differential evolution

This paper introduces a robust searching hybrid differential evolution (RSHDE) method to solve the optimal feeder reconfiguration for power loss reduction. The feeder reconfiguration of distribution systems is to recognize beneficially load transfers so that the objective function composed of power losses is minimized and the prescribed voltage limits are satisfied. Mathematically, the problem of this research is a nonlinear programming problem with integer variables. This paper presents a new approach, which uses the RSHDE algorithm with integer variables to solve the problem. Owing to handle the integer variables, the HDE may fail to find the initial search direction for large-scale integer system. This is because the HDE applies a random search at its initial stages. Therefore, two new schemes, the multidirection search scheme and the search space reduction scheme, are embedded into the HDE. These two schemes are used to enhance the search ability before performing the initialization step of the solution process. One three-feeder distribution system from the literature and one practical distribution network of Taiwan Power Company (TPC) are used to exemplify the performance of the proposed method. Moreover, the previous HDE, simulated annealing and genetic algorithms methods are also applied to the same example systems for the purpose of comparison. Numerical results show that the proposed method is better than the other methods.