Low-speed Sensorless Control Method of SPMSM for Oil Pump Based on Improved Pulsating High-Frequency Voltage Injection

摘要

Aiming at the problem that the sensorless surface-mounted permanent magnet synchronous motor has a certain failure rate and poor low-speed control performance, an improved sensorless rotor initial position detection and low-speed position tracking method is proposed. First of all, the pulsating high-frequency voltage is injected into the estimated coordinate system, and the relationship between current response and position error is obtained through the principle of flux linkage cross-coupling. The composite phase-locked loop rotor position observer is established by optimizing the filter and performing phase compensation of the modulation signal. Then, combined with pulse voltage vector injection, the conditions for determining the rotor polarity are given. This observer can accurately detect and track the rotor position from start to low speed in sensorle ss control. Finally, build a test platform for oil pump experiments, the experimental results verify that the method can realize the closed-loop start of the surface-mounted permanent magnet synchronous motor with large torque at rest, which improves the efficiency and robustness of low-speed operation.