Researches on Sensorless Control of PMSM in Full Speed Range

For sensorless control in the full speed range of PMSM, in the zero speed section and low speed section, the pulse vibration high frequency injection method is currently dominant. In this method, the parameter variations, inverse potential and cross-coupling terms have an impact on the rotor position estimation error, and the rotor position estimation error is obvious; in the medium and high speed sections, the sliding mode observer is currently dominant. Conventional counter potential sliding mode observer has a large amount of noise disturbance in the output counter potential due to its inherent jitter characteristics and measurement noise, and the use of low-pass filter makes the output counter potential have phase shift and amplitude weakening, which indirectly affects the estimation of rotor position and speed. The book combines the needs and practical experiences of sensorless control, and conducts research on several key issues in the full-speed range sensorless control of PMSM, and proposes several types of excellent rotor position estimation methods for permanent magnet synchronous motors and corresponding strategies to improve the rotor position estimation accuracy.