Research on speed fluctuation suppression of PMSM based on SADRC and QRC cascade control

The objective of this research is to reduce the speed fluctuation of Permanent Magnet Synchronous Motor (PMSM) due to periodic torque fluctuation. To achieve this, the authors designed a cascade control system based on Linear/Nonlinear Switching Active Disturbance Rejection Control (SADRC) and Quasi Resonant Controller (QRC). Periodic torque pulsations, mainly the first, second, and fourth harmonics, are analyzed first. The architecture of the SADRC and QRC cascade control systems is then established. Subsequently, the parameters of SADRC and QRC are calibrated by the bandwidth method, and a closed-loop system model of cascade control is developed. Ultimately, periodic load fluctuations with step load fluctuations are applied at the load side to ascertain the efficacy of the SADRC and QRC cascade control systems. The SADRC and QRC cascade control reduce the first, second, and fourth harmonics of speed fluctuations by 74%, 33%, and 47.5%, respectively, through the use of QRC current compensation in the presence of peak 2 N m periodic torque fluctuations. The SADRC and QRC cascade control systems demonstrate excellent performance in the context of cyclic and step load fluctuations.