Rotor structure design of interior permanent magnet brushless motors for sensor-less control

Based on the need for sensor-less control of interior permanent magnet (IPM) brushless motors, a computer-aided design method for phase inductance optimization is put forward. With this method, repeated manual design process is alleviated, and ideal phase inductance waves can be obtained which is beneficial to sensor-less control of IPM brushless motors. Besides, cogging torque is reduced and motor performance is improved. Transformation from an existing surface-mounted permanent magnet (SPM) brushless motor to IPM has been done to obtain an ideal phase inductance wave with the proposed method.