An Improved Hybrid Active Flux Observer With an Extended State Observer Based on A Quasi-Resonant Controller for Sensorless SPMSM Drives

The hybrid active flux observer, integrating the voltage model and current model, significantly expands the operational speed range. To suppress interference from uncertain errors and enhance control robustness, a hybrid active flux observer based on an extended state observer (ESO) has been proposed. However, since conventional ESO primarily addresses DC disturbances, this paper further develops a hybrid active flux observer with an extended state observer based on a quasi-resonant controller (QRCESO) to address AC disturbance effects. Additionally, conventional phase-locked loop (PLL) exhibits limited noise rejection capability. Therefore, this paper employs a 3rd order ESO (3rd-ESO) for speed and position estimation, which further suppresses AC noise interference. Experimental results validate the feasibility of the proposed method.