Low Speed Sensorless Control Of SPMSM Based On High Frequency Pulsating Signal Injection

The sensorless control technology of Permanent Magnet Synchronous Motor(PMSM) has emerged and become the research focus in the field of motor control. Because of low and zero speed sensorless control technology is the key to achieve full speed range sensorless control, and Surface Mounted Permanent Magnet Synchronous Motor(SPMSM) is the most widely used type of PMSMs, the low and zero speed sensorless control research of SPMSM is more urgent. Therefore, focused on sensorless control of SPMSM under low and zero speed, the high frequency pulsating signal injection method is presented in this paper.A brief introduction of PMSM and its control strategy is firstly presented, in which the presentation of sensorless control methods is highlighted.Then, the mathematical model of PMSM and the principle of vector control are analyzed, and the id=0 strategy is adopted. Furthermore, the inverter modulation strategies are compared, the three-phase carrier SPWM inverter modulation strategy is chosen to prepare for the sensorless control. The SPMSM vector control system model based on the three-phase carrier SPWM inverter modulation strategy with position sensor is constructed. The simulation results demonstrate the good performance of vector control system.The principles of magnetic saturated saliency and fluctuating high frequency signal injection are researched. On this basis, a novel initial rotor position detection method for the SPMSM which combines the high frequency pulsating signal injection method with the carrier frequency component method is proposed. Thus, the rotor magnetic pole can be detected without injecting other different signals. The initial position detection to start running at low speed sensorless control is achieved. In addition, the influence of the inverter nonlinear effect on precision of the sensorless control is considered, and the phase voltage compensation strategy is adopted. The simulation research of initial position detection, start running at low speed and the phase voltage compensation are studied respectively. The simulation results show that the proposed scheme is feasible.Finally, the hardware platform and the software system of the PMSM control system are developed. The experimental researches aiming at a SPMSM which power is 1.5k W are carried out,and the experimental results verified the correctness of the strategy.