Power converter and methods for increasing power delivery of soft alternating current power source

• US 10,333,299 B2
• Filed: 03/03/2014
• Issued: 06/25/2019
• Est. Priority Date: 03/05/2013
• Status: Active Grant

• Current Assignee: Acleap Power Incorporated
• Original Assignee: ABB Schweiz AG (ABB Limited)
• Inventors: Fontana, Edward Clark, Walter, Tab O, Davis, Roy Jaescentt, Subramaniam, Palanivel
• Primary Examiner(s): Barnie, Rexford N
• Assistant Examiner(s): Vu, Toan T
• Application Number:
  US14/195,594
• Publication Number:
  US 20140306526A1
• Time in Patent Office: 1,940 Days
• Field of Search: 307 24
• CPC Class Codes: H02J 2300/10 The dispersed energy generation being of fossil origin, e.g. diesel generators
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy wind motors F03D
• CPC Class Codes: H02J 3/00 Circuit arrangements for ac mains or ac distribution networks
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• 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
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects

Abstract

A power converter is provided that includes a detection circuit configured to determine a power source type based on at least one characteristic of power received from a power source. The detection circuit is also configured to determine an operating edge of the soft AC source by monitoring at least one parameter as the soft AC power source approaches a power limit, and assign an operating point to the soft AC power source based on the operating edge to increase power delivery of the soft AC power source.

Claims

1. A power converter for supplying power to a load, the power converter comprising:

a detection circuit in signal communication with a controller, the detection circuit configured to;

determine a power source type based on at least one characteristic of power received from a power source;

monitor at least one parameter of a soft AC power source;

determine, in response to detecting a change in the monitored parameter that satisfies a predefined amount of change, an operating edge of the soft AC power source, wherein the operating edge is indicative of a power output of the soft AC power source at which the detected change occurs and wherein the operating edge is less than a total amount of power that the soft AC power source is capable of producing;

calculate a scaled operating point associated with the soft AC power source that is less than the determined operating edge; and

utilize the scaled operating point in association with the soft AC power source.

2. A power converter in accordance with claim 1, wherein to determine the operating edge of the soft AC power source, said detection circuit is further configured to monitor a voltage droop of the soft AC power source as the soft AC power source approaches a power limit.

3. A power converter in accordance with claim 2, wherein to monitor a voltage droop, said detection circuit is further configured to determine a highest output voltage of the soft AC power source before current begins to drop as the soft AC power source approaches the power limit.

4. A power converter in accordance with claim 1, wherein to determine the operating edge of the soft AC power source, said detection circuit is further configured to monitor at least one of frequency, period, duty cycle, variations of frequency, components of current and voltage of power factor, phase differences in current and voltage, flip angle variations between current and voltage, and distortion.

5. A power converter in accordance with claim 1, wherein said detection circuit is further configured to determine a region of operation for the soft AC power source based on the determined operating edge.

6. A power converter in accordance with claim 1, wherein said detection circuit is further configured to operate the soft AC power source at the scaled operating point to deliver power to a load.

7. A power converter in accordance with claim 1, wherein the soft AC power source is a wind-powered generator.

8. A power converter in accordance with claim 7, wherein said detection circuit is further configured to operate the wind-powered generator over the operating edge in a pump mode for a predetermined time to increase the power transferred due to inertia in airflow as a blade of the wind-powered generator approaches stall.

9. A power converter in accordance with claim 1, wherein to utilize the scaled operating point in association with the soft AC power source, said detection circuit is further configured to:

determine a knee voltage of the soft AC power source, the knee voltage corresponding to a maximum output voltage of the soft AC power source;

set the scaled operating point to be near the knee voltage to utilize a full capacity of the soft AC power source.

10. A power converter in accordance with claim 1, wherein the power source comprises a plurality of power sources, and wherein the controller is configured to prioritize the conversion of power from each power source of the plurality of power sources relative to one another based upon predetermined parameters.

11. A method comprising:

coupling a power source to a load;

determining a power source type based on at least one characteristic of power received from the power source;

when a soft AC power source is determined to be the power source type, monitoring at least one parameter of the soft AC power source;

determining, in response to detecting a change in the monitored parameter that satisfies a predefined amount of change, an operating edge of the soft AC power source, wherein the operating edge is indicative of a power output of the soft AC power source at which the detected change occurs and wherein the operating edge is less than a total amount of power that the soft AC power source is capable of producing;

calculating a scaled operating point associated with the soft AC power source that is less than the determined operating edge; and

utilizing the scaled operating point in association with the soft AC power source.

12. A method in accordance with claim 11, wherein determining the operating edge of the soft AC power source comprises monitoring a voltage droop of the soft AC source as the soft AC power source approaches a power limit.

13. A method in accordance with claim 11, wherein determining the operating edge of the soft AC power source comprises monitoring at least one of frequency, period, duty cycle, and distortion.

14. A method in accordance with claim 11, further comprising determining a region of operation for the soft AC power source based on the determined operating edge.

15. A method in accordance with claim 14, further comprising:

measuring a voltage of AC input power being received; and

margining output voltage relative to a measured DC bus voltage to provide power to a load while maintaining operation of the soft AC power source within the region of operation.

16. A method in accordance with claim 11, further comprising prioritizing the conversion of power from each power source of a plurality of power sources relative to one another based upon predetermined parameters.

17. A power converter system comprising:

a plurality of power sources;

a direct current (DC) bus for providing power to at least one load; and

a power converter comprising a detection circuit configured to;

determine a power source type based on at least one characteristic of power received from a power source;

monitor at least one parameter of a soft AC power source;

determine, in response to detecting a change in the monitored parameter that satisfies a predefined amount of change, an operating edge of the soft AC power source, wherein the operating edge is indicative of a power output of the soft AC power source at which the detected change occurs and wherein the operating edge is less than a total amount of power that the soft AC power source is capable of producing;

calculate a scaled operating point associated with the soft AC power source that is less than the determined operating edge; and

utilize the scaled operating point in association with the soft AC power source to increase power delivery of the soft AC power source.

18. A power converter system in accordance with claim 17, wherein to determine the operating edge of the soft AC power source, said detection circuit is further configured to monitor at least one of voltage droop, frequency, I/frequency, duty cycle, variations of frequency, components of current and voltage of power factor, phase differences in current and voltage, flip angle variations between current and voltage, and distortion of the soft AC power source as the soft AC power source approaches a power limit.

19. A power converter system in accordance with claim 17, wherein said detection circuit is further configured to determine a region of operation for the soft AC power source based on the determined operating edge.

20. A power converter system in accordance with claim 17, further comprising a controller configured to prioritize the conversion of power from each power source of the plurality of power sources relative to one another based upon predetermined parameters.