Trade-off with starting capability to maximize efficiency of a single-phase line-start permanent magnet motor

This paper addresses trade-off with starting capability to maximize efficiency of a small single-phase line-start permanent magnet motor. In general, as the number of main winding turns is higher, the induced electromotive force is higher. As a result, as the input current is reduced, the copper loss of the stator windings (main and auxiliary windings) is lower. Therefore, the motor efficiency is higher and the start-up and synchronization capability is conversely lower. In this paper, the rotor with the excellent start-up and synchronization capability has been used. The effects of the number of main winding turns on the efficiency and starting capability are clear experimentally by using two single-phase line-start permanent magnet motors with different one. It has been found that the small difference of the number of main winding turns gives the important trade-off between the starting capability and efficiency.