Transient overvoltage control for a wind farm based on goal representation adaptive dynamic programming

With increasing intermittent and fluctuant wind power integrated into the power system, the high penetration of wind generation has brought a series of challenges including voltage stability for the safe operation of power system. Static VAR Compensator (SVC) has been widely used to control the voltage on the point of common coupling (PCC) of wind farm. When severe fault occurs and leads to serious voltage drop in the system, SVC controlled by the conventional control method may cause voltage overshoot after the fault clearance due to its response time lag. And this voltage overshoot of PCC may lead to the failure of high voltage ride through. In order to solve such a problem and improve the system voltage stability under severe fault conditions, a goal representation adaptive dynamic programming (GrADP) based SVC controller is proposed in this paper. The proposed control method can precisely control reactive output of SVC through its self-learning function to approximate the optimal control policy. Thus the voltage on the PCC is effectively controlled. An IEEE four-machine two-area system is used to verify the effectiveness of the proposed approach. Detailed simulation analysis and comparative studies with particle swarm optimization (PSO) optimized SVC controller are carried out to demonstrate the performance of the new method. Simulation results indicate that the proposed control strategy is effective in mitigating the voltage overshoot with good adaptability under various operating conditions.