Phase-shifted full-bridge converter based on an adjustable current auxiliary circuit with full load range ZVS and small duty cycle loss

In this paper, a phase-shifted full-bridge converter based on an adjustable current auxiliary circuit is proposed. The converter's switches achieve ZVS with the help of the parallel current provided by the auxiliary circuit. The conduction loss of the parallel current is reduced since the magnitude of the current can be adjusted by the variable inductor. Since there is no additional series inductor, the duty cycle loss of the proposed converter is minimal. Moreover, the oscillating voltage on the secondary side decays quickly, indicating that the energy involved in the oscillation is small, which is beneficial to reduce the loss of the RCD. The experimental platform is built. On this basis, theoretical analysis and experimental verification are carried out in this paper.