Design and Practical Implementation of Sensorless Control for Permanent Magnet Wind Turbine Systems

This paper presents the design, implementation, and experimental validation of a sensorless control architecture for a grid-connected permanent magnet synchronous generator (PMSG)-based wind energy conversion system (WECS). Unlike conventional sensorless schemes that focus primarily on machineside estimation, the proposed approach integrates sensorless field oriented control (FOC) on the machine-side converter with fully decoupled voltage oriented control (VOC) on the grid-side converter, enabling coordinated maximum power point tracking, stable DC link regulation, and seamless grid synchronization within a unified back to back converter framework. The control strategy is experimentally validated on a laboratory-scale test bench under low-speed wind conditions, where the DC link voltage is regulated at 150 V, and grid connection is achieved to a 60 V, 60Hz grid emulator. Experimental results demonstrate clean synchronization with balanced sinusoidal grid voltages and accurate current control. A step change in the d axis current reference from 0 to 1 A RMS (with zero q axis current) confirms fast and stable active power injection while maintaining zero reactive power exchange. The proposed setup establishes a flexible experimental platform for evaluating advanced PMSG control strategies, including active rectification, grid-support capabilities, and fault-ride-through.