Resonant converter with wide input voltage range and input current ripple-free

A current fed resonant converter is presented and developed to have the advantages of wide input voltage operation range and less ripple current. The developed circuit includes two boost inverters in the front stage and one resonant converter in the rear stage. Two boost converters are operated using interleave pulse-width modulation in order to reduce the input ripple current. The resonant converter with voltage doubler circuit topology is adopted to obtain high-voltage output and realise zero-voltage turn-on switching for all power switches over ail load ranges. The active switches of two boost converters and the resonant converter share the same power switches so that the switch counts in the studied circuit are reduced. In order to extend the input voltage operation range, an additional boost converter is active when the input voltage is lower than the defined voltage level. Therefore, a wide input voltage range operation, 2 , 4-76 V, of the developed circuit can be realised to apply in the fuel cells or solar cells input applications. The feasibility and practicality of the developed circuit are confirmed by the test results with an 800 W prototype circuit.