Optimum Design of a Single-Phase Line-Start PM Motor Considering Efficiency, Maximum Torque, and Starting Torque

In this paper, an optimum design for a single-phase line start permanent magnet (LSPM) motor with respect to efficiency, maximum torque, and starting torque is proposed. The design variables, objective functions, and constraints are selected for this optimum design, which is divided into three steps. Step I maximizes the rated efficiency while maintaining a balanced operation and minimizing the stator copper loss. Step II utilizes equivalent circuit analysis to consider the efficiency and the maximum torque, while Step III calculates the precise starting torque using finite element (FE) analysis. The validity of the optimum design is verified by comparing the efficiency, maximum torque, and starting torque characteristics of the time-step FE analysis with experimental results.