Alternative-Source Energy Management

• US 20110254372A1
• Filed: 03/15/2011
• Published: 10/20/2011
• Est. Priority Date: 05/08/2007
• Status: Active Grant

• Current Assignee: Schneider Electric IT Corporation (Schneider Electric SE)
• Original Assignee: American Power Conversion Corporation (Schneider Electric SE)
• Inventors: Haines, Lance P., Deokar, Vishwas M.
• Granted Patent: US 8,320,146 B2
• Time in Patent Office: Days
• US Class Current: 307/66
• 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 2300/26 involving maximum power point tracking control for photovoltaic sources maximum power point systems in particular G05F1/67
• 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 3/388 Islanding, i.e. disconnection of local power supply from the network
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies
• 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 converter system includes a power converter system including: a DC-to-AC power converter; a first output configured to be coupled to a power grid; a first input configured to be coupled to the power grid; second outputs each configured to be coupled to a corresponding AC load; a power-grid switch coupled to the converter and to the first output; load switches coupled to the converter, the second outputs, and the first input; and a controller coupled to the load switches and to the first output and configured to determine whether energy from the power grid satisfies at least one criterion, the controller being further configured to control the power-grid switch and the load switches to couple the converter to the first output and to couple the first input to the second outputs if the at least one criterion is satisfied and otherwise to control the power-grid switch and the load switches to isolate the converter from the first output and to couple the converter to at least one of the second outputs.

Claims

1. A power converter system comprising:

a DC-to-AC power converter;

a plurality of outputs each configured to be coupled to an AC load;

a plurality of load switches coupled to the converter and the outputs; and

a controller coupled to the load switches and to the outputs and configured to control the load switches to selectively couple the converter to the outputs to selectively provide AC power from the DC-to-AC power converter to the outputs dependent upon at least one characteristic associated with the outputs other than power drawn on the outputs to dynamically change the selective coupling of the converter to the outputs to dynamically change which of the outputs receive power from the converter.

2. The system of claim 1 further comprising a first DC source that is unidirectionally coupled to the DC-to-AC power converter to supply DC power to the DC-to-AC power converter, the system further comprising:

a second DC source comprising an energy storage device; and

a bidirectional DC-to-DC converter coupled to the energy storage device and to the DC-to-AC power converter.

3. The system of claim 1 further comprising a bidirectional DC-to-DC converter coupled to the DC-to-AC converter and configured to couple to an energy storage device.

4. The system of claim 1 wherein the first DC source comprises at least one of a DC-output generator and at least one solar panel.

5. The system of claim 1 wherein the at least one characteristic is at least one of whether a particular output is permitted to receive power from a particular source, and whether a particular output is associated with a delayable AC load.

6. The system of claim 1 further comprising an AC generator coupled to the load switches.

7. A method of regulating power delivery by a power delivery system, the method comprising:

determining whether a power grid with acceptable first AC power available is connected to the power delivery system;

receiving first DC power at a DC-to-AC converter from a first DC power source other than an energy storage device and converting the received first DC power from the first DC power source to second AC power;

providing the second AC power to the power grid if it is determined that a power grid with acceptable power available is connected to the power delivery system;

providing the second AC power to a first portion of a plurality of AC loads connected to the power delivery system if it is determined that no power grid with acceptable power available is connected to the power delivery system; and

changing from providing the second AC power to the first portion to providing the second AC power to a second portion of the plurality of AC loads while no power grid with acceptable power available is connected to the power delivery system, the second portion being different than the first portion;

wherein the second AC power is provided to the first portion of the AC loads dependent upon at least one characteristic of a load of the first portion of the AC loads in addition to power draw of the first portion of the AC loads.

8. The method of claim 7 wherein the at least one characteristic comprises delayability of the respective load.

9. The method of claim 7 wherein the at least one characteristic comprises permission of the respective load to receive power derived from the first DC source.

10. The method of claim 7 wherein providing the second AC power to the first portion of the AC loads comprises providing the second AC power in an amount only up to a threshold amount.

11. The method of claim 7 further comprising providing third AC power to a third portion of the AC loads dependent upon whether the third portion is permitted to receive power derived from a source of the third AC power.

12. The method of claim 11 further comprising receiving second DC power at the DC-to-AC converter from a second DC power source, comprising an energy storage device, and converting the received second DC power from the second DC power source to the third AC power.

13. The method of claim 11 further comprising receiving the third AC power from an AC generator.

14. The method of claim 13 further comprising:

receiving second DC power at the DC-to-AC converter from a second DC power source, comprising an energy storage device, and converting the received second DC power from the second DC power source to fourth AC power;

receiving fifth AC power from an AC generator; and

combining the fourth and the fifth AC power to form the third AC power.

15. The method of claim 11 wherein the first and second portions of the AC loads are physically separate such that the second and third AC powers are provided to physically separate loads.

16. A method of regulating power delivery by a power delivery system, the method comprising:

providing characteristics of AC loads;

providing indications of alternative power sources, which of the alternative power sources are permitted to power which of the AC loads, and priority of use of the alternative power sources, wherein the alternative power sources are connected to the power delivery system, wherein the alternative power sources are different from a power grid; and

powering the at least one of the AC loads using at least one of the alternative power sources, without using a power grid, based on the characteristics of the AC loads, the priority of use of the alternative power sources, and which of the alternative power sources are permitted to power which of the AC loads.

17. The method of claim 16 wherein the characteristics include load delayability.

18. The method of claim 16 wherein the alternative power sources include a source of renewable DC power, the method further comprising:

determining whether a power grid with acceptable AC power available is connected to the power delivery system; and

providing power to the power grid from the source of renewable DC power if it is determined that a power grid with acceptable power available is connected to the power delivery system.

19. The method of claim 16 wherein powering the AC loads comprises powering the AC loads without exceeding a power threshold.

20. The method of claim 16 wherein powering the AC loads comprises discontinuing to power a particular one of the AC loads if a power drawn by the powered loads exceeds an available power presently provided by the alternative power sources to the AC loads.

21. The method of claim 20 wherein the discontinuing comprises selecting the particular one of the AC loads based upon at least one of the load characteristics.

22. The method of claim 20 wherein the discontinuing comprises selecting the particular one of the AC loads based upon the priority of use of the alternative power sources.