Sensor-less fusion of speed for permanent magnet synchronous motors

In the field of electric motor control, extensive efforts have been devoted to the development of position sensorless motor drives. In this paper, a novel fusion algorithm is proposed. The algorithm seamlessly fuses the information generated by a high and a low-speed sensorless technique. The resulting sensorless drive, based on novel fusion algorithm, permits position sensorless operation over the entire speed range. Simulation results show minimal error between the estimated and actual motor position. Furthermore, it is shown that the novel fusion algorithm resolves the position polarity problem, which characterizes low-speed sensorless techniques.