An Effective Adaptive-Observer-Based Wide Range Encoderless Control for PMSM Drives

In this work, we propose a new adaptive-observer-based encoderless control for permanent magnet synchronous motor (PMSM) drives. The proposed solution achieves full speed range operation without signal injection. To enable and enhance zero- and very low-speed operation with large load, a technique with a new drop voltage adaptation law to precisely identify and compensate the inverter nonlinearity is proposed. In addition, we propose a comprehensive design to ensure the input-to-state stability of the proposed observer, whose stability proof is also provided. Only three design parameters are required; theoretical design guidelines, guaranteeing robustness against parameter uncertainties and measured dc bias, are provided. Finally, the proposed solution is verified at a lab-constructed test-bench, with off-the-shelf commercial controller. Experimental results validate the effectiveness of the proposed methods for different testing scenarios.