Optimal allocation of combined DG and capacitor for real power loss minimization in distribution networks

Optimal siting and sizing of Distributed Generation (DG) and shunt capacitor at the distribution networks for the purpose of real power loss minimization is drawing much attention of electric power utilities in the present days. Some inherent benefits of power loss minimization includes: reduction of power flow in feeder lines, releases stress on feeder loading, and hence increases their life time, adds opportunity to using the existing facility to serve any increased load demand, avoidance of power purchased from the grid and also the cost of loss compensating devices, reduction in customer bill, etc. In this paper, a method based on analytical approach for optimal allocation (sizing and siting) of DG and capacitor with the objective to minimize the total real power loss subjected to equality and inequality constraints in the distribution network is presented. A sensitivity analysis technique has utilized to identify the optimal candidate locations for DG and capacitor placement and the heuristic curve fitting technique is used to determine their optimal capacity in the networks. To validate the suitability of the proposed method, it has been applied to 12-bus and IEEE 33-bus test distribution systems. The obtained simulation results and comparison of different cases considered reveals that allocation of DG and capacitor combination results in significant loss reduction with good voltage profile and also release in the line loading in the power distribution networks. (C) 2013 Elsevier Ltd. All rights reserved.