A Sensorless Control Strategy for Wound Rotor Synchronous Machine Considering Parameter Variations

When the excitation current and load of wound rotor synchronous machine (WRSM) change, the d-q axis inductances of main generator (MG) are greatly affected by the serious nonlinear of the magnetic field saturation. In order to reduce the influence of parameter variations on the estimation accuracy of position and speed, a sensorless control scheme based on extended Kalman filter for WRSM is proposed in this paper. The position estimation model is only associated with the q-axis inductance, and is irrelevant to the d-axis inductance which is more susceptible to magnetic field saturation. The online identification for the q-axis inductance of MG is carried out by the recursive least square (RLS) algorithm, and the identified result are used to correct the estimation model. Experimental and simulation results are provided to validate the proposed strategy.