Three-level rectification DC/DC converter

A three-level rectification DC/DC converter, comprising:

• a primary circuit receiving an input voltage and comprising a plurality of primary switches;
• a resonant tank circuit comprising a resonant inductor, a resonant capacitor, and a transformer, wherein a first primary terminal and a second primary terminal of the resonant tank circuit are coupled to the primary circuit, a primary winding of the transformer is coupled between the first and second primary terminals, a secondary winding of the transformer is coupled between a first secondary terminal and a second secondary terminal of the resonant tank circuit, a voltage between the first and second primary terminals is a first voltage, a voltage between the first and second secondary terminals is a second voltage;
• and
• a secondary circuit comprising two clamping switches, a switch bridge arm, and a capacitor bridge arm, wherein the switch bridge arm comprises a first secondary switch, a second secondary switch, a third secondary switch, and a fourth secondary switch sequentially connected in series, the two clamping switches are connected in series between a node between the first and second secondary switches and a node between the third and fourth secondary switches, a node between the second and third secondary switches is connected to the first secondary terminal, the capacitor bridge arm comprises a first output capacitor and a second output capacitor connected in series, a node between the first and second output capacitors is connected to a node between the two clamping switches and the second secondary terminal, two terminals of the capacitor bridge arm are connected to two terminals of the switch bridge arm, and a voltage between the two terminals of the capacitor bridge arm is an output voltage,
• wherein the second secondary switch is at least in an on state for a preset time length after a falling edge in a period of the first voltage, and the third secondary switch is at least in the on state for the preset time length after a rising edge in the period of the first voltage,
• wherein the three-level rectification DC/DC converter operates in a continuous current mode,
• wherein if the first secondary switch and the fourth secondary switches are kept in an off state, the second secondary switch is switched from the off state to the on state at the falling edge in the period of the first voltage and is in the on state for the preset time length after the falling edge, and the third secondary switch is switched from the off state to the on state at the rising edge in the period of the first voltage and is in the on state for the preset time length after the rising edge.