An Improved Active-Front-End Rectifier Using Model Predictive Control

Abstract-This paper investigates an improved active-front-end (AFE) rectifier using model predictive control. The model predictive control (MPC) algorithm utilizes the discrete behavior of the power converter to determine the appropriate switching states by defining a cost function. The performance of the AFE rectifier has been verified with 3.0 kW experimental setup which shows that the efficiency of the MPC controlled AFE-rectifier is 96.82 % and is operated with acceptable THD (4.0%) of input current and very low DC voltage ripple. An efficiency comparison is performed between the MPC and VOC-based PWM controller of the AFE rectifier which ensures the effectiveness of MPC controller. Moreover, the stability of the MPC method has been analyzed with the root locus, discrete z-domain frequency response techniques (Nyquist diagram) and non-linear experimental system. The result confirms that, the control system of AFE rectifier is stable as it operates with infinite gain margin and very fast dynamic response. Keywords-Model predictive control (MPC); active front end (AFE) rectifier; stability analysis; AC-DC power conversion. I