Sensorless PMSM control for H-axis washing machine drive

In this paper a position and speed estimation method without position transducer is presented. This method is applied for horizontal axis washing machines with permanent magnet synchronous motor (PMSM). By integrating methods, i.e. using a speed reference for zero speed startup and low speed acceleration, and back-EMF for mid-high speed operation, the rotor position can be estimated and controlled over the full speed range. In order to achieve correct operation from zero speed, the two techniques are combined with a crossover function based on the speed reference. The proposed method can be used in applications with significant and unpredictable variation in loads, such as horizontal axis washing machines. Moreover, the proposed method can be applied on drives with surface mounted PMSM or motors with low or distorted saliency signature. To verify the functionality of the proposed method, experimental validation was conducted using horizontal axis washing machine.