A sliding mode duty-ratio control with current balancing algorithm for interleaved buck converters

In this work, a sliding mode duty-ratio controller (SMDC) with auto phase current balancing algorithm (CBA) is proposed for the interleaved buck converters. To achieve fast dynamic voltage regulation, a SMDC is proposed to generate the duty ratio based on the reference voltage tracking error. Due to the equivalent series resistances (ESR) mismatch, unbalanced phase currents may occur. To address this issue, based on a new multi-point synchronized dc-link current sensing, a novel CBA approach is proposed to adjust the duty ratio for each interleaved phase, such that the balanced phase currents can be achieved. The proposed method can be applied for either continuous or discontinues conduction mode. The effectiveness of the proposed approach has been verified using both simulation and experimental studies.