Resonant Converters with an Improved Voltage Regulation Range

Patent metadata

Field	Value
Publication number	US-2016294294-A1
Application number	US-201514676515-A
Country	US
Kind code	A1
Filing date	Apr 1, 2015
Priority date	Apr 1, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

A method comprises determining an operating mode based upon an input voltage and an output voltage of a resonant converter, wherein the resonant converter comprises a switch network coupled to an input dc power source, a resonant tank coupled to the switch network and a transformer coupled between the resonant tank and a secondary rectifier, wherein the secondary rectifier is a full-bridge rectifier, configuring the switch network to operate at a buck converter mode in response to a first input voltage and configuring the secondary rectifier to operate at a boost converter mode in response to a second input voltage, wherein the first voltage is higher than the output voltage and the second voltage is lower than the output voltage.

First claim

1 . A method comprising:
determining an operating mode based upon an input voltage and an output voltage of a resonant converter comprising:
a switch network coupled to an input dc power source and a resonant tank, wherein a transformer is coupled between the resonant tank and a full-bridge secondary rectifier;
configuring the switch network to operate at a buck converter mode; and configuring the full-bridge secondary rectifier to operate at a boost converter mode.

2 . The method of claim 1 , further comprising:
configuring the switch network to operate at the buck converter mode in response to a first input voltage; and configuring the full-bridge secondary rectifier to operate at the boost converter mode in response to a second input voltage, wherein:
the first voltage is higher than the output voltage of the resonant converter; and
the second voltage is lower than the output voltage of the resonant converter.

3 . The method of claim 1 , further comprising:
in the buck converter mode, controlling the switch network based on a phase-shift PWM scheme; and in the boost converter mode, shorting a secondary side winding of the transformer by turning on two switches of the full-bridge secondary rectifier.

4 . The method of claim 1 , further comprising:
in the buck converter mode, controlling the switch network based on a frequency modulation scheme; and in the boost converter mode, shorting a secondary side winding of the transformer by turning on two switches of the full-bridge secondary rectifier.

5 . The method of claim 1 , further comprising:
in the buck converter mode, controlling the switch network based on an asymmetric PWM scheme; and in the boost converter mode, shorting a secondary side winding of the transformer by turning on two switches of the full-bridge secondary rectifier.

6 . The method of claim 1 , further comprising:
in the buck converter mode, controlling two bottom switches of the switch network based on a PWM modulation scheme; and in the boost converter mode, shorting a secondary side winding of the transformer by turning on two switches of the full-bridge secondary rectifier.

7 . The method of claim 1 , wherein the full-bridge secondary rectifier comprises four switches, and wherein:
a first switch and a second switch are connected in series and further coupled between two terminals of an output capacitor; and a third switch and a fourth switch are connected in series and further coupled between the two terminals of the output capacitor.

8 . The method of claim 7 , wherein:
a secondary side winding of the transformer has a first terminal connected to a common node of the first switch and the second switch, and a second terminal connected to a common node of the third switch and the fourth switch.

9 . The method of claim 8 , further comprising:
simultaneously turning on the second switch and the fourth switch to short the secondary side winding of the transformer in the boost converter mode.

10 . The method of claim 8 , further comprising:
simultaneously turning on the first switch and the third switch to short the secondary side winding of the transformer in the boost converter mode.

11 . A system comprising:
a switching network configured to be connected with an input dc power source and operate at a buck converter mode in response to a first input voltage; a resonant tank coupled between the switching network and a primary side of a transformer; and a rectifier coupled between a secondary side of the transformer and an output capacitor and configured to operate at a boost converter mode in response to a second input voltage, wherein:
the first voltage is higher than a voltage across the output capacitor; and
the second voltage is lower than the voltage across the output capacitor.

12 . The system of claim 11 , wherein the rectifier is a full-bridge rectifier comprising:
a first switch and a second switch are connected in series and further coupled between two terminals of an output capacitor; and a third switch and a fourth switch are connected in series and further coupled between the two terminals of the output capacitor.

13 . The system of claim 12 , wherein:
a secondary side winding of the transformer has a first terminal connected to a common node of the first switch and the second switch, and a second terminal connected to a common node of the third switch and the fourth switch.

14 . The system of claim 12 , wherein:
the second switch and the fourth switch are configured to be simultaneously turned on to short the secondary side winding of the transformer.

15 . A method comprising:
enabling a resonant converter that comprising:
a switch network coupled to an input dc power source;
a resonant tank coupled to the switch network; and
a transformer coupled between the resonant tank and a full-bridge secondary rectifier;
in response to an output voltage of the input dc power source, determining an operating mode; configuring the switch network to operate at a buck converter mode in response to a first input voltage; and configuring the secondary rectifier to operate at a boost converter mode in response to a second input voltage, wherein:
the first voltage is higher than an output voltage of the resonant converter; and
the second voltage is lower than the output voltage of the resonant converter.

16 . The method of claim 15 , wherein:
the switch network comprises:
a first primary switch and a second primary switch connected in series and further coupled between two terminals of the input dc power source; and
a third primary switch and a fourth primary switch connected in series and further coupled between two terminals of the input dc power source;
a first terminal of a primary winding of the transformer is coupled to a common node of the first primary switch and the second primary switch through the resonant tank; a second terminal of the primary winding of the transformer is coupled to a common node of the third primary switch and the fourth primary switch; the full-bridge secondary rectifier comprises four switches, and wherein:
a first switch and a second switch are connected in series and further coupled between two terminals of an output capacitor; and
a third switch and a fourth switch are connected in series and further coupled between the two terminals of the output capacitor;
a first terminal of a secondary winding of the transformer is coupled to a common node of the first switch and the second switch; and a second terminal of the secondary winding of the transformer is coupled to a common node of the third switch and the fourth switch, and wherein the first terminal of the secondary winding and the first terminal of the primary winding share a same polarity.

17 . The method of claim 16 , further comprising:
in the boost converter mode, simultaneously turning on both the second switch and the fourth switch.

18 . The method of claim 16 , wherein:
in the boost converter mode, simultaneously turning on both the first switch and the third switch.

19 . The method of claim 16 , further comprising:
in the boost converter mode, simultaneously turning on both the second switch and the third switch when the first primary switch and the fourth primary switch are turned on.

20 . The method of claim 16 , further comprising:
in a first boost converter mode, simultaneously turning on both the second switch and the fourth switch; and in a second boost converter mode, simul

Assignees

• Futurewei Technologies Inc

Inventors

• Ye Liming
• Dai Heping
• Fu Dianbo
• Chen Daoshen

Classifications

• H02M3/33546 Primary

  with automatic control of the output voltage or current (H02M3/33561 takes precedence) · 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

• H02M3/33592 Primary

  having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer · CPC title

• 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