A hybrid switching scheme for LLC series-resonant half-bridge dc-dc converter in a wide load range

This paper presents a hybrid switching scheme for LLC series-resonant half-bridge (SRHB) dc-dc converter. The concept of the proposed hybrid switching scheme is changing the switching mode to improve power efficiency in a wide load range. The SRHB converter operates in three different switching modes depending on the output load condition. Digital control of the system facilitates the implementation of the proposed hybrid switching scheme. High efficiency is achieved with a constant output voltage over wide load range. Experimental results on a 5 kW prototype are presented to evaluate the feasibility of the proposed switching scheme for the SRHB converter.