A new starting method of sensorless PMSM motors based on STM32F103B

In this paper, we investigate position sensorless control technique for the permanent magnet synchronous motor (PMSM). We observed that when the current flows along the magnetic axis, there is variation of the current response caused by the magnetic saturation of the stator core of the PMSM. Based on the variation, we proposed a method of inspecting the PMSM rotor position at the standstill and a novel start-up method which laid foundation for controlling d-q axis current and frequency. The method ensures the success rate of start-up, prevents the motor reverse and the starting fault by reducing the start-up current and increasing the starting torque. Moreover, it is independent of the model of the motor and it is robust to motor parameter variations. Finally, our experimental results based on STM32F103B suggested that this method is feasible and can be applied effectively.