POWER INVERTER

• US 20100315850A1
• Filed: 06/12/2009
• Published: 12/16/2010
• Est. Priority Date: 06/12/2009
• Status: Active Grant

• Current Assignee: Veranda Solar, Inc.
• Original Assignee: Veranda Solar, Inc.
• Inventors: Jones, Peter, Fetscher, Emilie, J'Neva Devi, Capra
• Granted Patent: US 8,259,478 B2
• Time in Patent Office: Days
• US Class Current: 363/95
• CPC Class Codes: H02J 2300/10 The dispersed energy generation being of fossil origin, e.g. diesel generators
• CPC Class Codes: H02J 2300/20 The dispersed energy generation being of renewable origin
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy wind motors F03D
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: H02M 7/493 the static converters being arranged for operation in parallel
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects

Abstract

A power inverter is provided for converting DC power into AC power. The inverter may be operable to couple to two or more transformer modules each operable to convert at least a portion of the DC power to at least a portion of the AC power. In one embodiment, two or more transformer modules are removably coupled to the inverter. In an alternative embodiment, the inverter is capable of electrically coupling to an externally-housed transformer module. In an alternative embodiment, the inverter may include two or more transformer modules hard-wired into the device. The inverter may include an AC safety plug for releasably connecting to an AC power network and outputting AC power. The inverter may include one or more sensors configured to detect one or more properties of the AC power network for the purposes of determining whether a connection to the power network should be established.

Claims

1. A power inverter for converting a direct current (DC) power to an alternating current (AC) power, the inverter comprising:

an input terminal for connecting to an external DC power source, the DC power source having a DC power;

an inverter coupling circuit operable to electrically couple to a first transformer module and a second transformer module, wherein each transformer module is operable to convert at least a portion of the DC power to at least a portion of the AC power;

an output terminal for outputting the AC power to an AC power network;

an AC power network sensor for detecting a property associated with the AC power network;

a DC power sensor for detecting a property associated with the DC power source;

a first switch for electrically connecting the inverter coupling circuit to the output terminal, wherein the state of the first switch is determined by the AC power network sensor; and

a second switch for electrically connecting the DC power source to the inverter coupling circuit, wherein the state of the second switch is determined by the DC power sensor.

2. The power inverter of claim 1, wherein the output terminal is connected to an AC power network.

3. The power inverter of claim 1, wherein the output terminal is located on an output safety plug for outputting the AC power, the output safety plug comprising:

the output terminal, wherein the output terminal is operable to connect to a socket configured to receive the output safety plug, wherein the socket is connected to an AC power network;

a contact sensor for detecting a sufficient contact between the output terminal of the output safety plug and the socket, wherein the contact sensor is connected to the safety plug; and

a third switch for electrically connecting the inverter coupling circuit to the output terminal of the safety plug, wherein the state of the third switch is determined by the contact sensor.

4. The power inverter of claim 1, wherein the inverter coupling circuit includes a first slot operable to removably couple to the first transformer and a second slot operable to removably couple to the second transformer.

5. The power inverter of claim 1, further comprising a processor operable to control one or more parameters of the first transformer module or one or more parameters of the second transformer module.

6. The power inverter of claim 5, wherein the one or more parameters of the first transformer is whether the first transformer module is active or inactive.

7. The power inverter of claim 5, wherein:

the processor is contained in a first housing,

the inverter coupling circuit is contained in a second housing, and

the first housing is separate from the second housing.

8. The power inverter of claim 1, wherein the inverter coupling circuit is contained within a housing, and wherein the inverter coupling circuit is further operable to electrically couple to an external transformer module, the external transformer module being external to the housing.

9. The power inverter of claim 1, wherein:

the inverter coupling circuit is contained in a first housing,

the input terminal for connecting to an external DC power source is contained in a second housing, and

the first housing is separate from the second housing.

10. The power inverter of claim 1, wherein:

the inverter coupling circuit is contained in a first housing,

the output terminal for outputting the AC power to an AC power network is contained in a second housing, and

the first housing is separate from the second housing.

11. The power inverter of claim 1, wherein:

the input terminal for connecting to an external DC power source is contained in a first housing,

the output terminal for outputting the AC power to an AC power network is contained in a second housing, and

the first housing is separate from the second housing.

12. The power inverter of claim 1, wherein:

the first transformer module is contained in a first housing,

the second transformer module is contained in a second housing, and

the first housing is separate from the second housing.

13. The power inverter of claim 1, further comprising a power regulator configured as a maximum power point tracker (MPPT) or a DC to DC converter controlled by a maximum power point tracking algorithm.

14. A power inverter for converting a direct current (DC) power to an alternating current (AC) power, the inverter comprising:

an input terminal for connecting to an external DC power source, the DC power source having a DC power;

an inverter coupling circuit comprising a transformer operable to convert at least a portion of the DC power to at least a portion of the AC power;

an output safety plug for outputting the AC power, the output safety plug comprising;

an output terminal for connecting to a socket configured to receive the output safety plug, wherein the socket is connected to an AC power network;

a contact sensor for detecting a sufficient contact between the output terminal of the output safety plug and the socket, wherein the contact sensor is connected to the safety plug; and

a first switch for electrically connecting the inverter coupling circuit to the output terminal of the safety plug, wherein the state of the first switch is determined by the contact sensor;

an AC power network sensor for detecting a property associated with the AC power network;

a DC power sensor for detecting a property associated with the DC power source;

a second switch for electrically connecting the inverter coupling circuit to the output terminal of the output safety plug, wherein the state of the second switch is determined by the AC power network sensor; and

a third switch for electrically connecting the DC power source to the inverter coupling circuit, wherein the state of the third switch is determined by the DC power sensor.

15. The power inverter of claim 14, wherein the first switch and the second switch are the same switch.

16. The power inverter of claim 14, wherein the inverter coupling circuit is operable to electrically couple to an external transformer, wherein the external transformer is operable to convert at least a portion of the DC power to at least a portion of the AC power.

17. The power inverter of claim 14, wherein the inverter coupling circuit is operable to electrically couple to two or more external transformers, wherein the external transformers are operable to convert at least a portion of the DC power to at least a portion of the AC power.

18. A method for matching an optimal power rating of an inverter to a direct current (DC) input power comprising:

a) measuring the DC input power in a power inverter comprising two or more transformer modules;

b) determining the minimum number of transformer modules required to convert the measured DC input power into AC power, wherein each transformer module is operable to convert at least a portion of the DC input power into at least a portion of the AC power;

c) activating the minimum number of transformer modules required to convert the measured DC input power into AC power.

19. The method of claim 18, further comprising the step of repeating a) through c).

20. The method of claim 18, further comprising deactivating the two or more transformer modules in response to an external switch.