A New Soft Switched Flyback Converter with Active Energy Recovery Cell

This paper presents a new soft-switched flyback converter with an active energy recovery cell comprising of a semiconductor switch, three diodes and an L-C cell. The active resonant cell is used to recover and utilize the trapped leakage energy of the flyback transformer. All semiconductor switches of this converter change their states under zero voltage and/or zero current condition and the diodes recover softly. Moreover, both the switches are operated by the same gate pulse, simplifying the implementation of control and drive circuitry. The proposed converter enjoys the advantages of high efficiency, large power density and simplicity in gate drive circuitry requirement. Performance of the proposed converter has been successfully validated by experimentation on a laboratory scale hardware prototype, rated with nominal 90-110V input, 24 V, 72 W output and operating with 100 kHz switching frequency.