Encoderless Control for PMSM Drives Based on A Robust Hybrid Flux Observer

This paper proposed a disturbance observer based on a hybrid flux model for encoderless control of permanent magnet synchronous motors (PMSMs). The method combines the advantages of current based and voltage-based flux models. A Generalized Proportional Integral Observer (GPIO) is designed on the hybrid flux model to compensate for time-varying disturbances, thereby improving flux estimation accuracy. The proposed approach significantly suppresses time-varying disturbances while maintaining rapid recovery of flux estimation accuracy under parameter variations, ensuring system dynamic performance and stability.