Research on third-harmonic injection based on nonlinear active disturbance rejection

Abstract

Abstract With the rapid development of power electronic technology and the permanent magnet industry, Permanent Magnet Synchronous Motor (PMSM) is widely used in high-tech industries such as aerospace and transportation with excellent performance. However, PMSM is a time-varying system with multiple variables and strong coupling, making its control strategy rather complex. It is becoming increasingly important to improve the control strategy. Addressing the issues of easy saturation, poor robustness in PI controllers, and the inconvenience of injecting third-harmonic from the outside into the three-phase three-leg topology to enhance torque density, which leads to insufficient control precision in the PMSM servo system, a nonlinear active disturbance rejection controller (NLADRC) is proposed as the control strategy for the third-harmonic injection-based field-oriented control (FOC). Compared to the PMSM servo system without the injection of third-harmonic, the proposed system exhibits better disturbance rejection capability and higher torque density. Through simulations of the PMSM servo system with the injection of third-harmonic, the proposed control strategy is verified to have good response speed and control performance.