“Sensorless Vector Control of Single Phase Line Start Permanent Magnet Motors (LSPMs)

Abstract

In this paper, sensorless vector control of single phase line-start permanent magnet (LSPM) motors is proposed. Providing two phase voltages for the motor, both start-up and run-up capacitors are eliminated. The provided voltage is such that, electrical angle between main and auxiliary windings voltages is 90 degrees and their amplitude ratio is related to the windings turn ratio. Accordingly, air gap magnetic flux will be similar to the circular form and then the torque pulsation is reduced as same as the three phase motor. Moreover a novel speed/position sensorless control for is developed for closed-loop control of LPMSM that yields a cost effective and reliable solution. In order to improve the efficiency of control, a Maximum Torque per unit Current (MTPC) method is used, in which the stator current vector is controlled based on the load condition. This method provides maximum torque for a given current. This, in turn, minimizes copper losses for a given torque. Finally, the simulation results are provided to confirm the proposed control design.