Implementation of soft-switching bidirectional flyback converter without auxiliary switch

A new bidirectional flyback converter is introduced in this study. To provide soft-switching condition, two identical auxiliary circuits are applied to both sides of the converter, without using any extra switches. These circuits do not impose high voltage or current stresses on the converter. To transfer the power in each direction, only one switch is gated through pulse-width modulation technique. So, the control circuit of this converter is very simple. Regardless of the power flow direction, the switch of the converter is turned on under zero-current condition and is almost turned off under zero-voltage condition. The experimental results of the proposed bidirectional converter are presented to verify the theoretical analysis.