Decoupled Average Current Balancing Method for Interleaved Buck Converters with Dual Closed-Loop Control

Abstract

Dual closed-loop feedback control is commonly used to regulate the output voltage of interleaved buck converters. Meanwhile, current balancing control is used to balance inductor currents between the sub-modules. However, the coupling of dual closed-loop and balancing loop will cause interaction between control loops and complicate the design of controller parameters. In this paper, a decoupled average current balancing method with parallel dual closed-loop control is proposed. Based on the small signal model of interleaved buck converters, the decoupling conditions of dual closed-loop and balancing loops are derived. Then, the decoupled average current balancing control is designed. The small-signal transfer functions show that proposed current balancing loops and dual closed-loop are decoupled. Therefore, the controller parameters of each control loop can be designed independently. Finally, the experimental results are presented to validate the effectiveness of the proposed control method.