Control strategy for a mid-size wind energy convertion system

A control strategy for a mid-size Permanent Magnet Synchronous Machine (PMSM) based Wind Energy Conversion System (WECS) operating under unbalanced voltages and currents is presented in this paper. The analyzed WECS is based on a PMSM connected through a non-controlled rectifier to the DC-bus. This paper proposes a new control strategy for improving the wind energy conversion efficiency based on the DC voltage regulation. In addition, in order to eliminate over-currents risk during unbalanced conditions, a control scheme has been designed to independently control positive and negative sequence currents. The proposed controller is based on the feedback linearization technique and shows an improvement in the system performance regarding 2ω ripple elimination in the DC voltage arising during AC-side imbalances and an accurate and decoupled active and reactive power tracking.