PMSM sensorless control based on Sliding Mode Observers methodology for nonlinear systems with model imprecision

The paper proposes a new Sliding Mode Observer (SMO) applied in sensorless control of Permanent Magnet Synchronous Machine (PMSM) considering model imprecision. In this implementation the PMSM model and proposed SMO are both expressed in the γδ estimated reference frame. Operating in sliding mode an extended state observer uses the provided equivalent control input to estimate the modified back EMF (MBEMF) and its disturbance. The state tracking is additionally strengthened by the equivalent control leading to sufficient chattering reduction. Simulation results demonstrate the effectiveness of the developed observer scheme considering uncertainty conditions.