New hybrid sensorless speed of a non-salient pole PMSG coupled to wind turbine using a modified switching algorithm

The paper focuses on the design of position and speed observers for the rotor of a non-salient pole permanent magnet synchronous generator (NSPPMSG) coupled to a wind turbine. With the random nature of wind speed this observer is required to provide a position and speed estimates over a wide speed range. The proposed hybrid structure combines two observers and a switching algorithm to select the appropriate observer based on a modified weighting coefficients method. The first observer is a higher-order sliding mode observer (HOSMO) based on modified super twisting algorithm (STA) with correction term and operates in the medium and nominal wind speed ranges. The second observer is used in the low speed range and is based on the rotor flux estimation and the control by injecting a direct reference current different to zero. The stability of each observer has been successfully assessed using an appropriate Lyapunov function. The simulation results obtained show the effectiveness and performance of the proposed observer and control scheme. •A new hybrid observer is proposed to estimate the position and speed of a non-salient pole PMSG driven by a wind turbine.•The hybrid structure combines two observers and allow the system to operate safely over a wide speed range without losing control.•The proposed switching algorithm is based on the weighting coefficients method.•Speed control is based on fuzzy logic to provide robustness and performance at low speeds.•Several simulation scenarios are presented to demonstrate the performance of the wind power system.