Rotor Flux Linkage Identification of Permanent Magnet Synchronous Machine Without Rotor Position Sensor Under Load Conditions

In the conventional rotor flux linkage identification method for permanent magnet synchronous motor (PMSM) drive systems without rotor position sensors, the identification accuracy decreases significantly as the load increases. It is, therefore, not applicable in most industry applications when the motor is loaded. This article proposes a rotor flux linkage identification method which is suitable for PMSM without a rotor position sensor under different load conditions to address this issue. Accurate rotor flux linkage identification under a wide range of load conditions can be achieved while the motor operates in the conventional $I/f$ control mode only once, indicating that the proposed method is effective and easy to implement.The error analysis, furthermore, shows that this method has strong robustness against parameter mismatch. The experimental results show that the identification accuracy of the proposal under different loads has improved significantly compared with the conventional method.