Optimal use of decentralized methods for volt/var control in distribution networks

摘要

This paper presents results of a heuristic optimization method for parameterization of decentral reactive power control, which can be used to improve static voltage quality in distribution grids. With an optimized Q(V)-curve it is possible to significantly reduce the additional reactive energy and accomplish lower losses in the grid while keeping the voltage within the specified limits. In this paper results for Q(V)-control and optimized cosφ(P)-curves with optional voltage regulated distribution transformers are presented. It is shown that the gradient of a Q(V)-curve should be as steep as possible. The optimization method also shows positive impact of bigger reactive power capability of each DG unit. Individual Q(V)-parameters for a group of distributed generators can significantly improve the efficiency of Q(V). The comparison with results using Optimal Power Flow shows a significant gap between optimal decentralized methods and coordinated optimization. Using coordinated optimization it is possible to reduce the yearly reactive energy of all DG units by over 95%.