Line-start permanent magnet synchronous motor starting capability improvement using pole-changing method

Line-start permanent magnet synchronous motor has many advantages, but it has two important defects are poor starting torque and synchronization capability. This paper presents a pole-changing of line-start permanent magnet synchronous motor which has a 6/8 pole-changing stator winding. A new structure of stator winding is designed to realize pole-changing. This motor can eliminate braking torque and pulsating torque at start-up effectively and improve the motor's starting capability significantly. The two-dimensional (2D) finite element method (FEM) is implemented to design and analyze the motor. The results show that pole-changing line-start permanent magnet synchronous motor at start-up can significantly improve the motor's starting performance.