Improved nonlinear extended state observer based on model compensation for Interior permanent magnet synchronous motors sensorless drives

This article proposes a sensorless control strategy based on an improved linear extended state observer (INLESO) to address the control issues of interior permanent magnet synchronous motors (IPMSMs) under wide range speed adjustment and large load disturbances. Firstly, optimize the EEMF model of IPMSM through model compensation methods to reduce the complexity of the salient pole structure. Secondly, combining the advantages of linear extended state observer (LESO) and nonlinear ESO (NLESO), an improved NLESO (INLESO) is proposed to reduce phase delay and improve convergence speed. Then, the orthogonal phase-locked loop (EQPLL) is improved using Euler’s multiple angle formula to accurately extract velocity and position information during rapid turning. The simulation and experimental results show that compared with traditional LESO, this strategy can maintain high stability and efficiency in a wide speed range and large load torque disturbances. These improvements significantly enhance the reliability and applicability of sensorless IPMSM drivers.