Performance characteristic of interleaved LLC resonant converter with phase shift modulation

Abstract

In this paper, the effect of phase shift modulation on the LLC resonant converter for an interleaved LLC resonant converter with phase shift modulation is investigated. The LLC resonant converters can achieve zero voltage switching (ZVS) of the primary switches and the zero current switching of secondary switches. Due to the sinusoidal shapes and discontinuous conduction of secondary current, the peak of secondary current is large. The interleaving operation for the LLC resonant converter has difficulty in synchronizing switching instants among phases owing to the parameter mismatches of resonant circuits. To solve this issue, the interleaved LLC resonant converter with phase shift modulation is proposed. The effect of phase shift modulation on the LLC resonant converter is investigated. It is confirmed that the proposed method is suitable for the operation below series resonant frequency.