A new duty-cycle-shifted PWM control scheme for half-bridge DC-DC converters to achieve zero-voltage-switching

A modified ZVS half-bridge DC-DC converter

“…Recently, various soft-switching PWM converters have been proposed combining the advantages of the conventional PWM converter with the resonant converters [1][2][3][4][5][6][7][8][9][10][11][12]. Among these converters, the phase-shifted zerovoltage-switching full bridge is one of the most attractive techniques, since it allows all switches to operate at Zero-Voltage Switching (ZVS) by utilizing transformer leakage inductance and junction capacitance of MOSFETs without adding an auxiliary switch [1][2][3].…”

“…The main drawback of the symmetric half-bridge topology is that both switches operate at hard switching conditions. Moreover, during the off-time period of the two switches, the oscillation between the transformer leakage inductance and junction capacitance of primary switches results in energy dissipation due to the diodes reverse recovery [11].…”

“…A ZVS half-bridge DC-DC converter based on the Duty-Cycle-Shifted (DCS) PWM control is presented to achieve ZVS for all switches [11][12]. By changing the distribution of duty cycles, one of the two primary-side switches achieves ZVS utilizing the transformer leakage inductance and reflected load current for wide load variations.…”

“…In Section IV, the prototype and experimental results are presented. The conclusion is given in Section V. The concept of the DCS control is shifting one of the two symmetric drive signals close to the other, while keeping the PWM control mode [11]. As a result, ZVS may be achieved because one switch turns on just after the other switch turns off.…”