High Efficiency High Frequency Resonant Power Conversion

• US 20140225439A1
• Filed: 02/10/2014
• Published: 08/14/2014
• Est. Priority Date: 02/14/2013
• Status: Active Grant

• Current Assignee: Quanten Technologies Limited
• Original Assignee: NuVolta Technologies, Inc.
• Inventors: Mao, Hengchun
• Granted Patent: US 9,755,534 B2
• Time in Patent Office: Days
• US Class Current: 307/31
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00308 Overvoltage protection
• CPC Class Codes: H02M 1/0058 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 Class Codes: H02M 3/3376 with automatic control of output voltage or current
• CPC Class Codes: H02M 7/4815 Resonant converters H02M7/4811 and H02M7/4826 take precedence
• CPC Class Codes: Y02B 70/10 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

Abstract

A power converter comprises a switch network coupled to an input voltage, a power transformer having a primary winding and a secondary winding, wherein the primary winding is coupled to the switch network, and the secondary winding is coupled to a rectifier, wherein the rectifier is coupled to an output voltage, a primary resonant tank having a first resonant capacitor and a first resonant frequency, and coupled to the primary winding of the power transformer and the switch network, and a regulation circuit configured to control the output voltage of the power converter to be substantially proportional to the input voltage and the switch network to operate at a frequency substantially close to the first resonant frequency.

Claims

1. A power converter comprising:

a switch network coupled to an input voltage;

a power transformer having a primary winding and a secondary winding, wherein the primary winding is coupled to the switch network, and the secondary winding is coupled to a rectifier, wherein the rectifier is coupled to an output voltage;

a primary resonant tank having a first resonant capacitor and a first resonant frequency, and coupled to the primary winding of the power transformer and the switch network; and

a regulation circuit configured to control the output voltage of the power converter to be substantially proportional to the input voltage and the switch network to operate at a frequency substantially close to the first resonant frequency.

2. The power converter of claim 1, wherein the secondary winding is coupled to a secondary resonant tank comprising at least a second resonant capacitor and having a second resonant frequency, wherein the second resonant frequency is substantially close to the first resonant frequency.

3. The power converter of claim 1, wherein the transformer has a feedback winding which is coupled to a signal conditioning circuit, which is in turn coupled to the regulation circuit and provides a feedback signal substantially proportional to the output voltage.

4. The power converter of claim 3, wherein the feedback signal is adjustable based upon a load current.

5. The power converter of claim 3, wherein the feedback winding is part of the primary winding of the power transformer.

6. The power converter of claim 1, wherein the regulation circuit has a reference substantially proportional to the input voltage.

7. The power converter of claim 6, wherein the reference is adjustable based upon a load current.

8. The power converter of claim 1, wherein the power converter has more than one output.

9. A system having a power converter comprising:

a switch network coupled to an input voltage;

a power transformer having a primary winding and a secondary winding, wherein the primary winding is coupoled to the switch network, and the secondary winding is coupled to a rectifier, wherein the rectifier is coupled to an output voltage;

a primary resonant tank having a first resonant capacitor and a first resonant frequency, and coupled to the primary winding of the power transformer and the switch network; and

a secondary resonant tank comprising at least a second resonant capacitor and having a second resonant frequency, and coupled to the secondary winding of the power transformer, wherein the second resonant frequency is substantially close to the first resonant frequency.

10. The system of claim 9 comprising further a regulation circuit configured to control the output voltage to be substantially proportional to its input voltage and the switch network to operate at a frequency substantially close to the first resonant frequency.

11. The system of claim 9, wherein the transformer has a feedback winding, and the feedback winding is coupled to the regulation circuit through a signal conditioning circuit and provides a feedback signal substantially proportional to the output voltage.

12. The system of claim 9, wherein the primary resonant tank has a series resonant circuit.

13. The system of claim 9, wherein the primary resonant tank has a parallel resonant circuit.

14. The system of claim 11, wherein the signal conditioning circuit performs rectification and filtering to the signal.

15. A method to control a power converter comprising:

sensing a signal substantially proportional to an output voltage of the converter, wherein a primary resonant tank having a first resonant frequency is coupled to a transformer having a primary winding and a secondary winding;

constructing a reference substantially proportional to an input voltage; and

configuring a regulation circuit wherein the signal and the reference are compared to control a switching frequency of the converter to be a value substantially close to the resonant frequency of the primary resonant tank in steady state.

16. The method of claim 15, wherein the secondary winding of the transformer is coupled to a secondary resonant tank having a second resonant frequency, wherein the second resonant frequency is substantially close to the first resonant frequency.

17. The method of claim 15, wherein the switching frequency is set initially to a high value and the regulation circuit adjusts the switching frequency to a lower steady state value.

18. The method of claim 15, wherein the switching frequency is set initially to a low value and the regulation circuit adjusts the switching frequency to a higher steady state value.

19. The method of claim 15 further comprising sensing the output voltage from a feedback winding of the power transformer.

20. The method of claim 19, wherein the feedback winding is part of the primary winding of the power transformer.