Auto-disturbance rejection control for three-phase voltage-type PWM rectifier

Traditional voltage-outer-loop controllers have weak disturbance rejection ability, therefore, auto-disturbance rejection control (ADRC) for three-phase voltage-type pulse-width-modulation (PWM) rectifier is proposed. Based on the PWM rectifier model in the synchronous reference frame, a current-inner-loop controller is designed with the feedback linearization control method. The traditional ADRC is improved with the new nonlinear state error feedback function. Moreover, its convergence speed is faster than the speed of the linear state error feedback function, and the chattering of the traditional ADRC is eliminated. The voltage-outer-loop controller and its parameters tuning methods are given based on the improved ADRC. Experimental results show that, the proposed PWM rectifier control system has better steady and dynamic performances, and especially has a good rejection ability of disturbances in AC voltage and DC load. © 2011 State Grid Electric Power Research Institute Press.