Current control techniques for utility interface converters with low THD

This paper discusses current control techniques for utility interface converters with low total harmonic distortion (THD), fast dynamic responses, and high stability for transient responses. A repetitive control technique with designed phase margin has been developed to reduce the THD of a single-phase boost AC/DC converter operating over a wide range of load variations. A green-mode control strategy is developed to adjust the control mode as well as the switching frequency for efficiency improvement. A predictive current loop controller is used to achieve fast dynamic response under wide input voltage variation range and a repetitive controller is designed to minimize periodic errors within the current loop bandwidth. A single-chip DSP controller is used to realize the proposed control scheme. Simulation and experimental results confirm the feasibility and performances of the proposed control scheme.