IMPROVED GENETIC ALGORITHMS FOR OPTIMAL POWER-FLOW UNDER BOTH NORMAL AND CONTINGENT OPERATION STATES

This paper presents an improved genetic algorithm (IGA) to solve the p roblem of optimal power flow. The GA, with the dynamical hierarchy of the coding system developed in this paper, has the ability to code a l arge number of control variables in a practical system within a reason able length string. It is, therefore, able to regulate the active powe r outputs of generators, bus voltages, shunt capacitors/ reactors and transformer tap-settings to minimize the fuel costs. Two cases in the IEEE 30-bus system for both normal and contingent operation states hav e been studied. In the contingent state, the circuit outage is simulat ed in one branch which causes a power flow violation in the other bran ch. The IGA always finds the best results and eliminates operational a nd insecure violations. (C) 1997 Elsevier Science Ltd.