Novel multi resonant ZVS high frequency power converter with high efficiency power conversion

A novel multi resonant ZVS high frequency power converter (N MR-ZVS HF-PC) for low load resistance is developed. The high amplitude of the load current with suppressed switching current of the power converter ensures high efficiency of power conversion. The N MR-ZVS HF-PC is composed of only two passive circuit components of Cs and Cp except of Lo and Ro of load equivalent circuit for induction heating. The principle of ZVS operation of the N MR-ZVS HF-PC based on the multi resonant technology is elucidated. The new circuit topology that the current ratio of Ar of maximum load current and maximum switch current is defined only by capacitance ratio of Cp/Cs and is no relation to load condition of Lo, Ro and output frequency of fo is introduced. The ZVS operation region with variable output power in pulse frequency modulation (PFM) is numerically analyzed. The high efficiency operation of the N MR-ZVS HF-PC is verified by experiments.