DC bus current optimization control strategy in DFIG wind power systems with current source converter

摘要

This paper proposes the dc bus current optimization control strategy in DFIG wind power systems with current source converter (CSC). In CSC-based systems, the converter losses are dependent on the dc bus current so that it is important to reduce it to minimum. The dc current is chosen as the larger value of rotor side converter (RSC) current and grid side converter (GSC) current. The RSC current is usually larger than GSC current because RSC will provide the generator's exciting current additionally. If the generator's stator can provide some reactive power to provide part of the exciting current, and the GSC compensate this part of reactive power to keep the grid working in unit power factor condition, the dc bus can be reduced further. The detailed control strategies for optimum dc bus converter are proposed. The simulation results has verified the validation of dc bus current optimization control strategy.