Design and Implementation of a ZCS-PWM Half-Bridge Boost Rectifier With Output Voltage Balance Control

This paper provides a zero-current-switching (ZCS)-pulse width modulation (PWM) half-bridge boost rectifier with output voltage balance control using ZCS auxiliary resonant circuits. In the proposed ZCS-PWM half-bridge boost rectifier, ZCS in the active switches and ZCS in passive switches are performed without additional current stress. In addition to reduce switching losses, significant reductions in the conduction loss and in the current stress are realized because the circulating current for the soft-switching flows only through the auxiliary circuit. The steady-state analysis is performed for operation illustration, and the small-signal model is built up for output regulation control and power factor correction (PFC). An average-current-mode for PFC is utilized to control the proposed ZCS-PWM half-bridge boost in the continuous conduction mode. The two output capacitor voltage imbalance is inherent in the half-bridge rectifier, and therefore the balance control technique is added to be more complete for this research. The operational principles, design considerations, and realizations are discussed and verified. The specification of the proposed ZCS-PWM half-bridge boost is rated at 400 W and operates at 30 kHz, with an input ac voltage of 110 V_rms and a regulated output voltage 400 V_dc, for experiments to verify the theoretic analysis of the proposed ZCS-PWM half-bridge boost with output voltage balance control.