A Sliding Mode Observer Based on CSSMC Algorithm For PMSM

In the domain of sensorless control for Permanent Magnet Synchronous Motors (PMSM), the Sliding Mode Observer (SMO) serves as a robust estimation technique that reconstructs the rotor position and angular speed by observing the extended back-electromotive force (EMF). This approach leverages the inherent discontinuous switching characteristics of sliding mode control to achieve high-precision state estimation while maintaining strong robustness against parameter uncertainties and external disturbances. However, the SMO exhibits inherent limitations, including suboptimal convergence dynamics due to fixed-gain switching and pronounced chattering phenomena caused by ideal discontinuous control actions. To optimize the SMO for PMSM sensorless control, this study implements the cascade spiral sliding mode control (CSSMC) algorithm for observer design, resulting in the cascade spiral sliding mode observer (CSSMO), which achieves accelerated convergence of state estimation errors and simultaneous suppression of high-frequency chattering.