Composite Gain-Scheduled Control Design for IPMSM Speed Regulation Using an Extended State Observer

Abstract

The study presents a composite gain-scheduled control system integrated with an estimation technique based on an Extended State Observer (ESO) to enhance the robustness and tracking performance of the Interior Permanent Magnet Synchronous Motor (IPMSM) drive system under varying operating conditions. The composite control system comprises an integral state feedback controller (I-SFC) enhanced with a dynamic gain scheduling mechanism, and an extended state observer (ESO). The ESO is designed to account for the mechanical dynamics of the IPMSM and is incorporated in the speed control loop to estimate the lumped disturbance affecting the loop. The design of the scheduled controller involves approximating the nonlinear dynamic model of an IPMSM into a parameterized linear formulation that relies on scheduling variables, namely load disturbance and reference speed, to accommodate changes in linear
dynamics. An integral state feedback control with a gain scheduling mechanism is then developed to regulate the linearized model. The controller regularly updates the linear model and modifies the gain settings based on current disturbance estimates and reference speed to ensure stability and accurate tracking under varying operating conditions. The effectiveness of the proposed control scheme is validated through simulation tests in the MATLAB/Simulink environment. Simulation results demonstrate that the proposed scheduled I-SFC method significantly outperforms the fixed-gain I-SFC method, particularly regarding dynamic performance and robustness to disturbances.