Sensorless Vector Control of IPMSM in Full Speed Range

For the Interior permanent magnet synchronous motor (IPMSM), according to the principle of minimizing the current vector amplitude required to output the same torque, the vector control strategy of maximum torque per ampere control (MTPA) below the base speed and flux weakening above the base speed is adopted. At this time, the copper loss of the motor is the smallest and the efficiency of the motor is the best. For the rotor position information required in vector control, the sliding mode observer is used to estimate the rotor position and speed in the medium and high-speed section, the high-frequency square wave voltage signal injection method is used to estimate the rotor position information in the low-speed section, and the weighting coefficient method is used to realize the smooth switching of the observation algorithms in the low-speed section and the medium and high-speed section. The Simulink simulation results show that the proposed method can accurately track the current working point and rotor position of vector control, and the rotor position error is controlled within 0.02 radian in steady-state operation.