Optimized Current Sharing Technique for Interleaved CLLC Converters for Minimal Output Current Distortion

Abstract:
An optimized current sharing technique (OCST) is proposed in this paper for a converter with 3 CLLC interleaved converters with slight differences in their respective resonance frequencies due to tolerance in the high-frequency transformers. The underlying optimization problem aims at minimizing the output current ripple and is solved offline, resulting in an optimization vector that defines the output DC current sharing and the phase lags between the 3 converters. The resulting technique demonstrates a significant reduction both in the DC current and DC voltage ripples.