Development of a Combined Control System to Improve the Performance of a PMSG-Based Wind Energy Conversion System Under Normal and Grid Fault Conditions

Fast transient and smooth steady-state performance of wind energy conversion systems (WECSs) is essential for sustained power conversion and grid code fulfilment including low voltage ride through capability. In this paper, an analysis of permanent magnet synchronous generator (PMSG)-based WECSs under vector control and direct torque control provides the basis for combining salient features of the two control methods into a reliable and effective control system to provide enhanced machine performance. The system includes two hysteresis current controllers in connection with an inverter-switching table. The proposed control provides fast transient and smooth steady-state performance for machine side converter of PMSGs, which controls dc-link voltage under grid fault conditions. Extensive simulation results on a 2-MW PMSG-based WECS demonstrate the desired performance of the proposed control system under both grid-normal and -fault conditions.