Sensorless technique applied to PMSG of WECS using sliding mode observer

This paper proposes a sensorless speed technique for variable speed wind turbine (WT) with permanent magnet synchronous generator (PMSG) applied to implement the maximum power point tracking (MPPT) of WT. Initially the PMSG model is developed, then a sliding mode observer is described in details aiming to obtain the generator speed estimate. Whenever the wind speed is below the nominal value, the estimated wind turbine speed is used to calculate the optimum torque to maximize the aerodynamics efficiency. Then, by controlling the boost converter current it is possible to impose this desired torque. Experimental results are provided to support the theoretical analysis as well as to demonstrate the good performance of the proposed sensorless algorithm.