Performance of line start permanent magnet synchronous motor with single-phase supply system

The operation of a three-phase induction motor from a single-phase supply with a capacitor in circuit is well known. While detailed investigations on the performance of the induction motor under such operating conditions are well reported in the literature, no such work is reported for the synchronous motor. The line-start permanent-magnet synchronous motor (LSPMSM) is actively being considered as an energy efficient alternative to the induction motor in general purpose, heavy duty applications. The paper presents an analytical and experimental evaluation on the performance of a three-phase LSPMSM fed from a single-phase supply. This analysis is carried out using symmetrical component theory. A capacitor is connected across two stator phases during starting and running. Estimation of the capacitor value to achieve the desired objectives, such as minimum unbalance, maximum power factor, maximum torque or maximum efficiency, is carried out. Load tests are conducted to validate the simulation results.