Self-Sensing Control of Wound Rotor Synchronous Motor Drive for Mine Hoist

Control of a wound rotor synchronous motor (WRSM) drive for a mine hoist has to address specific properties. One of them is reliable and safe operation without sensor of the rotor position. To fulfill this requirement, we propose a sensorless vector control allowing drive operation with maximum available torque. The proposed sensorless rotor position estimation utilizes natural ac components of the rotor field excitation current. This component acts as a modulation signal, which has measurable effect on the stator currents and can be used to estimate the actual position of the rotor. We investigate two techniques for identification of the rotor position: The phase-lock loop and the extended Kalman filter. Both techniques are able to estimate the rotor position and magnetic polarity. However, the Kalman filter offers faster convergence and higher accuracy. It is able to provide reliable rotor position estimation in the whole speed range of the drive. Proper function of the introduced control algorithm is verified by simulations and experiments made on a developed small-scale prototype of a mine hoist drive of rated power of 10 kW.