A Single-phase Line-start Pm Motor Design Method-from Three-phase To Single-phase

High efficiency motors have been needed in a large variety of industrial products in order to save electrical energy. The single-phase induction motor has advantages such as simple structure and low-cost production. Thus,it has used primarily for the home appliance. However, the single-phase induction motor has low efficiency caused by copper loss of rotor and vibration caused by unbalanced magnetic field. contrary, the single-phase line-start permanent magnet motor(LS-PMSM) is capable of very high efficiency and near unity power factor performance as there is loss caused by the slip induction. In particular, the single-phase LS-PMSM can be used immediately instead of the conventional induction motors for application in pumps,air conditions and fans.The design and performance analysis of single-phase line-start permanent magnet motors is more difficult and complicate than three-phase ones due to the asymmetry existed in the single-phase LS-PMSM stator windings and especially due to the limit to single phase voltage supply. This paper presented an effective and simple method for the single-phase LS-PMSM design, which starts from designing a three-phase LS-PMSM with the required rated power and other specifications by using any existing method or software, then transforming the designed three-phase sysmmetric stator windings to two-phase windings based on producing the same effective space ampere-turns. The method details are introduced. A design example is given with performance analysed by using FEM, and the result shows that this method is very practicable.