Method and apparatus for power converter input voltage regulation

Patent metadata

Field	Value
Publication number	US-9583946-B2
Application number	US-201113116587-A
Country	US
Kind code	B2
Filing date	May 26, 2011
Priority date	May 27, 2010
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

A method and apparatus for regulating an input voltage to a power conversion module. In one embodiment, the method comprises computing a voltage regulation threshold based on an output voltage for the power conversion module; comparing an input voltage of the power conversion module to the voltage regulation threshold; and generating, when the input voltage satisfies the voltage regulation threshold, an average input voltage less than the voltage regulation threshold, wherein the average input voltage is generated from the input voltage.

First claim

The invention claimed is:

1. A method for regulating an input voltage to a DC/AC power conversion module, comprising:
computing a voltage regulation threshold based on an AC line voltage of a power grid to which the DC/AC power conversion module is coupled;
comparing a value of the input voltage of the DC/AC power conversion module to the voltage regulation threshold; and
modifying the input voltage to generate a modified input voltage when the value of the input voltage exceeds the voltage regulation threshold, wherein the modified input voltage has an average voltage value that is less than the voltage regulation threshold such that the input voltage or the modified input voltage is maintained at a level that is less than the voltage regulation threshold.

2. The method of claim 1 , wherein generating the modified input voltage comprises driving at least one switch.

3. The method of claim 2 , wherein the modified input voltage is generated via fully symmetric switching.

4. The method of claim 2 , further comprising determining a switching rate, based on the value of the input voltage, for driving the at least one switch.

5. The method of claim 1 , wherein the voltage regulation threshold is based on a lowest rectified line-to-line voltage value of an AC line coupled to the DC/AC power conversion module.

6. The method of claim 5 , wherein the voltage regulation threshold is equal to a difference between the AC line voltage and a set value margin.

7. The method of claim 2 , wherein the at least one switch is driven using at least one of pulse width modulation (PWM), Space Vector PWM, or predictive modulation.

8. Apparatus for regulating an input voltage to a DC/AC power conversion module, comprising:
a voltage regulator module for (i) computing a voltage regulation threshold based on an AC line voltage of a power grid to which the DC/AC power conversion module is coupled; (ii) comparing a value of the input voltage of the DC/AC power conversion module to the voltage regulation threshold; and (iii) driving an input voltage regulator to generate a modified input voltage when the value of the input voltage exceeds the voltage regulation threshold, wherein the modified input voltage has an average voltage value that is less than the voltage regulation threshold such that the input voltage or the modified input voltage is maintained at a level that is less than the voltage regulation threshold.

9. The apparatus of claim 8 , further comprising the input voltage regulator, wherein the voltage regulator module drives at least one switch of the input voltage regulator to modify the input voltage.

10. The apparatus of claim 9 , wherein the input voltage regulator provides fully symmetric switching.

11. The apparatus of claim 9 , wherein the voltage regulator module determines a switching rate, based on the value of the input voltage, for driving the at least one switch to generate the input voltage.

12. The apparatus of claim 8 , wherein the voltage regulation threshold is a lowest rectified line-to-line voltage value of an AC line coupled to the DC/AC power conversion module.

13. The apparatus of claim 12 , wherein the voltage regulation threshold is equal to a difference between the AC line voltage and a set value margin.

14. The apparatus of claim 9 , wherein the at least one switch is driven using at least one of pulse width modulation (PWM), Space Vector PWM, or predictive modulation.

15. A power inverter comprising:
an input voltage regulator receiving an input voltage;
a DC-AC inversion stage comprising at least an H-bridge circuit;
an AC voltage sampler coupled to an AC line of a power grid for measuring an AC line voltage of the power grid to which the power inverter is coupled; and
a controller operative to receive AC voltage samples to determine a voltage regulation threshold, and control the input voltage regulator to generate a modified input voltage that is maintained at a level that is less than the voltage regulation threshold.

16. The power inverter of claim 15 , wherein the input voltage regulator further comprises at least one switch driven to generate the modified input voltage as an average input voltage to the DC-AC inversion stage by fully symmetric switching.

17. The power inverter of claim 16 , wherein the controller receives samples of the input voltage from an I-V monitoring circuit to determine a switching rate, based on the value of the input voltage, for driving the at least one switch to generate the modified input voltage.

18. The power inverter of claim 17 , wherein the I-V monitoring circuit is coupled between an input of the power inverter and the input voltage regulator.

19. The power inverter of claim 15 , wherein an input of the DC-AC inversion stage is coupled to an output of the input voltage regulator by an inductor.

20. The power inverter of claim 15 , further comprising a voltage monitoring circuit coupled between the input voltage regulator and the DC-AC inversion stage, such that the voltage monitoring circuit monitors the input voltage.

Assignees

• Fornage Martin
• Enphase Energy Inc

Inventors

• Fornage Martin

Classifications

• H02M7/48

  using discharge tubes with control electrode or semiconductor devices with control electrode · CPC title

• H02M7/537

  using semiconductor devices only, e.g. single switched pulse inverters · CPC title

• H02J2101/24

  Photovoltaics · CPC title

• H02J3/383 Primary

  Electricity · mapped topic

• H02M2001/007

  Electricity · mapped topic