Improved Active Disturbance Rejection Control for PMSM Based on Modified Extended State Observer

Active disturbance rejection control (ADRC) is a new algorithm used in permanent magnet synchronous motor (PMSM) drive system which has a better tracking performance than proportional-integral (PI). Extended state observer (ESO) is the core part of ADRC which can estimate the total unknown disturbances and compensate for the influences in the closed-loop dynamics. The observation accuracy of ESO directly affects the compensation ability of the system. In order to promote the observation precision of ESO and improve the control performance of ADRC, a modified-structure ESO is proposed in this paper. Some simulation experiments are performed and the results indicate that the proposed controller can provide better speed dynamic and static performance under load disturbances.