Optimal VAR Planning Considering Intermittent Wind Power Using Markov Model and Quantum Evolutionary Algorithm

Techniques for distributed generations (DGs) have attracted increasing attention due to their effects on environmental sustainability and the reduction in traditional megawatt (MW) generation expansion. Wind farms are one of the DGs and have intermittent characteristics. This paper presents a method for static VAR planning considering existing wind generator voltages and transformer taps as controllers to regulate the voltage profile in a distribution system with wind farms. Wind power generations and bus loads are modeled with the Markov model. The probabilities and durations of the operation states are obtained. Through a quantum evolutionary algorithm, the cost of static VAR compensators and MW loss in the system are minimized and the operational constraints are fulfilled. The applicability of the proposed method is verified through simulations using a standalone 25-bus (Penghu) system and a 17-bus system.