LLC resonant DC-DC converter for high voltage applications

In this paper, an LLC resonant dc-dc converter is proposed for high voltage applications. Full bridge inverter, LLC resonant tanks, high voltage transformer and full bridge rectifier are comprised in the proposed converter circuit. In operating frequency of proposing converter, output voltage regulation is achieved by narrow varying. The energy trapped in leakage inductance of the transformer and to achieve ZVS feature, LLC resonant circuit is utilized to retrieve. It also increases conversion efficiency. A high voltage transformer is used to step up AC voltage which is then refined by the rectifier. With the equivalent circuit derived by first harmonic approximation (FHA method, input-output response and DC characteristics in frequency domain are obtained. The theoretical equations of the circuit operations are studied in detail to infer. Finally, a design example is implemented out to establish the feasibility of the proposed LLC resonant converter. The simulation results on the essential switching and circuit operation are presented. The robustness of this study is verified by the simulation results of the proposed converter with 300V input and 3.5kV/0.35A output.