Full digital deadbeat speed control for permanent magnet synchronous motor with load compensation

A full digital deadbeat controller is proposed for the speed loop to obtain better dynamic response performance in permanent magnet synchronous motor servo system. Given an expected target error function and speed command in Z-domain form, according to the deadbeat zero-pole configuration rules, the digital controller is derived to make the current command output stable in several sampling periods and the speed response also becomes stable without ripples. To reject disturbance from the load variation, an estimation method, based on model reference adaptive system through Popov´s hyper stability criteria, is presented to identify online the moment of inertia and load torque. The two quantities are essential for the speed loop to achieve adaptive control by load compensation. The simulation and experimental results reveal the effectiveness of the proposed speed controller.