A novel feed-forward and feed-back control of a VSI for variable speed wind-driven PM alternators

摘要

This paper brings out an improved control strategy for an inverter employed to integrate a 3-kW wind-driven permanent-magnet synchronous generator (PMSG) to the utility network. The proposed controller features a feed-back control for enhanced current tracking performance and a feed-forward control for power tracking with varying wind-speeds. The harmonic content of the current fed to the grid is minimised by a hybrid feed-back controller comprising PI and hysteresis blocks in cascade. The feed-back current controller derives a varying current reference with varying wind-speed from the feed-forward control loop. This paper brings out the ability of the controller to vary the amplitude of the inverter-current with varying wind-speed, without distorting the inverter current waveform. Simulation results of a wind-driven PMSG integrated to a single-phase grid using an inverter with the proposed control is presented. Waveform obtained from an experimental test-rig is also given.