Sliding mode variable structure direct power control of permanent-magnet direct drive generator

The pulse width modulation technique and dynamic operating mode characteristics of direct drive permanent magnet synchronous generator (PMSG) are researched firstly. A novel sliding mode variable structure directed power control algorithm applied to PMSG is proposed, and then design the controller using tip speed radio and flux-weakening control scheme. It can not only provide a constant switching frequency without involving any synchronous speed coordinate transformation and generator side phase information, but also can reduce the capacitance of generator-side converter. Simulation and experimental results show that the proposed theoretical analysis method and control strategy is effective under the platform PSCAD/EMTDC.