A high frequency transformer isolated inverter expecting no duty cycle loss

An isolated inverter based on differential output is proposed. The inverter is composed by two phase-shifted full bridges (PSFB) converters. The two PSFBs share a common leg which works as the lagging one on the primary side. Two current-doubler synchronous rectifiers (CDR) are on the secondary side and constitute differential structure. With the same DC bias and phase-reversed AC components in the two PSFBs, an AC output voltage is acquired. Compared to traditional H-bridge inverters which claim high-quality outputs, the new configuration has the potential capability to obtain ultra-low distortion in output voltage without using any special control or compensations, because there is no duty cycle loss in each PSFB. Moreover, switches on the primary side can realize zero voltage switching (ZVS) within a wide load range, while the ones on the secondary side can achieve zero current switching (ZCS). Finally, simulation model and a 1kW prototype are built to verify the effectiveness of the proposed scheme.