Analysis and Design of LLC Based Dual Half Active Bridge Resonant Converter

In this paper, a high frequency isolated LLC based dual half active bridge resonant converter (DHABRC) is proposed. An electrolytic capacitor is often required for power conversion units which has many operational and reliability issues like short life-span, size and weight etc. The need of electrolytic filter capacitors required at input-output terminals of a DC-DC converter has been eliminated by replacing two active switches of a full bridge configuration with film capacitors. This leads to the reduction in number of switch counts of proposed DHABRC. Also, the complexity and cost of the topology will be reduced. The proposed DHABRC has been analyzed using modified fundamental harmonics approximation (FHA) to reduce the computational burden. The conditions for the soft-switching have been derived to obtain high efficiency over a wide range of load. For the verification of the proposed converter, experimental results are included for a 500 W laboratory prototype.