Smoothing of output power of PMSG-based WECS and enhancing FRT during grid faults

This paper presents a smoothing of an output power of wind energy conversion systems (WECS) with permanent magnet synchronous generator (PMSG) and enhancing the fault-ride through (FRT) capability during grid faults. It uses three main control methods: pitch angle control method, inertia of the wind turbine and DC-link voltage control. The generator side converter is used to control the PMSG torque for achieving stable power smoothing of the WECS while the grid-side inverter is used to control the DC-link and grid voltages. For the proposed method, the torque smoothing is effective for the reduction of torque difference and is controlled by the inertia of the wind turbine. The FRT requirement is imposed on a wind power generator so that it remains stable and connected to the grid during faults. The effectiveness of the proposed method is verified by the numerical simulations.