A Position Sensorless Control Method Robust to Inductance Mismatch for SynRM Based on Generalized Multiple Model Resonant Kalman Filter

Synchronous reluctance motors (SynRM) have a highly nonlinear flux-current mathematical relationship, making it difficult to obtain accurate inductance information. The Kalman filter-based position estimation method is designed by using a single active back electromotive force (AEMF) model. When inductance parameter mismatch occurs, the estimation performance of the AEMF observer designed by using the single-model resonant Kalman filter (SM-RKF) is more sensitive to inductance parameter deviation as the load increases. To inhibit the effects of inductance parameter mismatch on the SynRM sensorless control system, the position estimation method based on a generalized multiple model resonant Kalman filter (GMM-RKF) is proposed. First, a new AEMF model of the SynRM is derived at maximum inductance-oriented coordinate frame. Second, the model set of GMM-RKF is built by RKF1 and RKF2 observers, which are derived from the two AEMF models. The two observers exhibit different parameter sensitivity characteristics at different current vector angle ranges. In comparison with SM-RKF, GMM-RKF has superior robustness against inductance mismatch since it combines the areas in two RKFs where the position estimation is robust to inductance mismatch. The effectiveness of the proposed sensorless control scheme is verified through an experimental prototype.