A new hybrid evolutionary strategy for reactive power dispatch

The problem of reactive power dispatch is to allocate reactive power generation so as to minimize the real power transmission losses and keep all the voltages within the limits, while satisfying a number of equality and inequality constraints. This paper presents a new method for solving this problem based on evolutionary strategy (ES). Some major improvements are added to the traditional ES in order to improve the convergence and to find a better solution. This improved technique is referred to as hybrid evolutionary strategy (HES). A conscious effort is made in the design of HES to reduce the number of load flow executions so that computational requirements are within reasonable limits. Extensive testing of HES is done and the results compared with those reported in the literature. These results show that HES converges to better solutions by evaluating considerably less number of solution strings and even lesser number of load flow executions as compared to the other evolutionary algorithms reported. (C) 2003 Elsevier Science B.V. All rights reserved.