Voltage Support Control Strategy of PMSG Wind Turbines During Unbalanced Grid Fault

This paper highlights the necessity of supporting the point of common coupling (PCC) voltage by the fully rated converter of permanent magnet synchronous generator (PMSG) type wind turbines under unbalanced voltage sags. According to the positive and negative sequence reactive currents injected into the grid by the grid side converter (GSC) are related to the voltage of each phase at PCC during asymmetric grid faults, a voltage support control strategy is proposed. The proposed method can achieve the purpose of supporting the PCC voltage of the grid and enhance the asymmetric ride-through capability of the wind turbine. And it can retain the sequence component characteristics of the current in the event of asymmetrical faults in the grid. The effect of different control options has been demonstrated using simulation on a test network and conclusion deduced.