Study of Steady-state Performances for a Novel Line-start Single-phase Permanent Magnet Synchronous Motor With Three Parallel-connected Windings

Several wire circuits have presented on the three-phase induction motor running on a single-phase supply,such as Smith and SEMIHEX.However,few suitable wire circuits have proposed for the three-phase line-start permanent magnet synchronous motor(LSPMSM).In this study,the novel LSPMSM with three parallel-connected windings has been put forward by applying the parallel-connected windings on the three-phase LSPMSM.First of all,the positive sequence impedance and negative sequence impedance of three-phase LSPMSM are presented,subsequently based on the symmetrical component method,the condition for balanced operation is analyzed and the method for determining the requested capacitances is also obtained.Then,the approach for calculating the steady-state performance is brought out.Finally,two prototypes,one with higher power factor and another with lower power factor,are designed,based on which,detailed experimental researches are carried out.It is concluded that,three-phase LSPMSM with lower power factor is better suited to be reconnected to the novel single-phase LSPMSM.And compared with three-phase LSPMSM of the same capacity,the single-phase LSPMSM reconnected from the three-phase LSPMSM with lower power has nearly the same efficiency when operating at rated load but with a higher power factor.