Three-level rectification DC/DC converter

Patent metadata

Field	Value
Publication number	US-12255539-B2
Application number	US-202217574027-A
Country	US
Kind code	B2
Filing date	Jan 12, 2022
Priority date	Dec 2, 2021
Publication date	Mar 18, 2025
Grant date	Mar 18, 2025

Abstract

The present disclosure provides a three-level rectification DC/DC converter including primary and secondary circuits and a resonant tank circuit. A voltage between two primary terminals is a first voltage. The secondary circuit includes a flying capacitor, a switch bridge arm, and a capacitor bridge arm. The switch bridge arm includes four switches serially connected. Two terminals of the flying capacitor are respectively connected between the first and second switches and connected between the third and fourth switches. Two secondary terminals are respectively connected between the second and third switches and connected between two output capacitors of the capacitor bridge arm. In two consecutive periods of the first voltage, the first and second switches are in an on state for a preset time length after two falling edges respectively, and the third and fourth switches are in the on state for the preset time length after two rising edges respectively.

First claim

What is claimed is:

1. 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 a flying capacitor, 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, two terminals of the flying capacitor are connected to a node between the first and second secondary switches and a node between the third and fourth secondary switches respectively, 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 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 first, second, third, and fourth secondary switches have a same switching frequency, there are two rising edges and two falling edges in two consecutive periods of the first voltage, during the two consecutive periods, the first secondary switch is at least in an on state for preset time length after one of the two falling edges, the second secondary switch is it least in the on state for the preset time length after one of the two ling edges, the third secondary switch is at least in the on state for the preset time length after one of the two rising edges, and the fourth secondary switch is at least in the on state for the preset time length after another one of the two rising edges.

2. The three-level rectification DC/DC converter according to claim 1 , wherein a first rising edge, a first falling edge, a second rising edge, and a second falling edge occur sequentially in the two consecutive periods of the first voltage, the first and second secondary switches are at least in the on state for the preset time length after the first and second falling edges respectively, and the fourth and third secondary switches are at least in the on state for the preset time length after the first and second rising edges respectively.

3. The three-level rectification DC/DC converter according to claim 2 , wherein phases of the fourth, first, third, and second secondary switches are sequentially out of phase by 90 degrees.

4. The three-level rectification DC/DC converter according to claim 2 , wherein the switching frequency of the first, second, third, and fourth secondary switches is equal to a half of a frequency of the first voltage.

5. The three-level rectification DC/DC converter according to claim 1 , wherein a first rising edge, a first falling edge, a second rising edge, and a second falling edge occur sequentially in the two consecutive periods of the first voltage, the first and second secondary switches are at least in the on state for the preset time length after the second and first falling edges respectively, and the fourth and third secondary switches are at least in the on state for the preset time length after the first and second rising edges respectively.

6. The three-level rectification DC/DC converter according to claim 5 , wherein phases of the second, third, first, and fourth secondary switches are sequentially out of phase by 90 degrees.

7. The three-level rectification DC/DC converter according to claim 5 , wherein the switching frequency of the first, second, third, and fourth secondary switches is equal to a half of a frequency of the first voltage.

8. The three-level rectification DC/DC converter according to claim 1 , wherein the first, second, third, and fourth secondary switches are further in the on state during a partial duration within a duration of currents flowing reversely through the first, second, third, and fourth secondary switches respectively.

9. The three-level rectification DC/DC converter according to claim 8 , wherein a duty ratio of the first, second, third, and fourth secondary switches are equal to 25%.

10. The three-level rectification DC/DC converter according to claim 1 , wherein the first, second, third, and fourth secondary switches are further in the on state during all durations within a duration of currents flowing reversely through the first, second, third, and fourth secondary switches respectively.

11. The three-level rectification DC/DC converter according to claim 10 , wherein driving signals of the first and fourth secondary switches are complementary, and driving signals of the second and third secondary switches are complementary.

12. The three-level rectification DC/DC converter according to claim 1 , wherein the preset time length is obtained based on the input voltage and the output voltage.

13. The three-level rectification DC/DC converter according to claim 1 , wherein all the primary and secondary switches are turned on with zero voltage switching.

14. The three-level rectification DC/DC converter according to claim 1 , wherein the first voltage is a square wave which is at a high level in one-half period and at a low level in the other half period.

15. The three-level rectification DC/DC converter according to claim 1 , wherein the primary circuit comprises an input capacitor, a first bridge arm, and a second bridge arm connected to each other in parallel, a voltage on the input capacitor is the input voltage, the first bridge arm comprises a first primary switch and a second primary switch connected in series, a node between the first and second primary switches is connected to the second primary terminal, the second bridge arm comprises a third primary switch and a fourth primary switch, and a node between the third and fourth primary switches is connected to the first primary terminal.

16. The three-level rectification DC/DC converter according to claim 1 , wherein the primary circuit comprises a flying capacitor, a first bridge arm and a second bridge arm, a voltage between two terminals of the first bridge arm is the input voltage, the two terminals of the first bridge arm are connected to two terminals of the second bridge arm respectively, the first bridge arm comprises a first input capacitor and a second input capacitor connected in series, the second bridge arm comprises a first primary switch, a second primary switch, a third primary switch, and a fourth primary switch sequentially connected in series, two terminals of the flying capacitor of the primary circuit are connected to a node between the first and second primary switches and a node between the third and fourth primary switches respectively, a node between the second and third primary switches is connected to the first primary terminal, and a node between the first and second input capacitors is connected to the second primary terminal.

Assignees

• Delta Electronics Shanghai Co

Inventors

• Zhang Chi
• Jia Minli
• Sun Hao
• Zhang Jinfa
• Barbosa Peter Mantovanelli

Classifications

• Y02B70/10

  Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes · CPC title

• H02M1/0058

  by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero (using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826) · CPC title

• H02M3/33584 Primary

  Bidirectional converters · CPC title

• H02M1/088

  for the simultaneous control of series or parallel connected semiconductor devices · CPC title

• H02M1/32

  Means for protecting converters other than automatic disconnection · CPC title