A novel interleaved LLC resonant converter with phase shift modulation

This paper presents a novel interleaved LLC resonant converter using phase shift modulation (PSM). The LLC resonant converters can achieve zero voltage switching (ZVS) of primary switches and zero current switching (ZCS) of secondary switches. However, the peak of secondary current is large due to the discontinuous current in secondary side. The PFM controlled interleaved LLC resonant converter has difficulty in synchronizing switching of phases owing to the parameter mismatches of resonant circuits. In the proposed method, the current unbalance caused by the parameter mismatches is compensated by the PSM. It is simulated and experimentally verified that the proposed method achieves lower peak current compared to conventional interleaved LLC resonant converters using only PFM control.