H APF harmonic mitigation technique for PMSG wind energy conversion system

This paper focuses on current harmonics mitigation at the permanent magnet synchronous generator (PMSG) wind turbine system using a variable frequency active power filter (VF-APF) harmonic mitigation technique. Mitigation of current harmonics in the PMSG reduces harmonic losses, thus reducing the heating effect on the PMSG cause by the current harmonic components and extends the lifespan of the PMSG. The current harmonics in the wind turbine system is mainly caused by non-linear loading effect from the AC-DC converter in the wind energy conversion system (WECS). Therefore, to filter current harmonics component in the PMSG, a conventional fixed frequency grid connected 3-phase-shunt APF is applied to compensate the current harmonics in the WECS PMSG generator. The conventional APF is coupled with a phase-lock-loop (PLL) synchronizer to facilitate variable frequency functionality. The simulation results shown in this paper is conducted at PMSG WECS maximum power point conditions. The demonstrated results show that the designed VF-APF successfully mitigates the PMSG current harmonic over a wide range of wind speed.