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

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 off-line, 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.