Power control systems and methods

• US 10,790,665 B2
• Filed: 09/11/2018
• Issued: 09/29/2020
• Est. Priority Date: 09/13/2015
• Status: Active Grant

• Current Assignee: Alpha Technologies Services, Inc. (EnerSys)
• Original Assignee: Alpha Technologies Services, Inc. (EnerSys)
• Inventors: Faley, Brian, LeBow, David, Bhatt, Pankaj H.
• Primary Examiner(s): Deberadinis, Robert L
• Application Number:
  US16/128,339
• Publication Number:
  US 20190140449A1
• Time in Patent Office: 749 Days
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• 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 5/00 Circuit arrangements for transfer of electric power between ac networks and dc networks H02J3/36 takes precedence
• CPC Class Codes: H02M 3/04 by static converters
• CPC Class Codes: H02M 7/44 by static converters
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving

Abstract

A power supply configured to operatively connect at least one load to at least one DC power source comprises an AC bus, a DC bus, a DC/AC converter, and a load balancer. The AC bus is adapted to be operatively connected to the load. the DC/AC converter is operatively connected between the DC bus and the AC bus. The load balancer is adapted to be operatively connected to the at least one DC power source and operatively connected to the DC bus. The power supply supplies power to the load from the first DC power source through the load balancer, the DC bus, the DC/AC converter, and the AC bus.

Claims

1. A power supply configured to operatively connect at least one load to at least one DC power source, the power supply comprising:

an AC bus adapted to be operatively connected to the load;

a DC bus;

a DC/AC converter operatively connected between the DC bus and the AC bus; and

a load balancer adapted to be operatively connected to the at least one DC power source and operatively connected to the DC bus;

wherein

the power supply supplies power to the load from the first DC power source through the load balancer, the DC bus, the DC/AC converter, and the AC bus.

2. A power supply as recited in claim 1, in which the load balancer substantially equalizes the charge on first and second split rail capacitors.

3. A power supply as recited in claim 1, in which the load balancer comprises a resonant capacitor and a resonant inductor connected in series.

4. A power supply as recited in claim 1, in which load balancer comprises a balance circuit that is alternately connected between first and second split rail capacitors.

5. A power supply as recited in claim 1, further comprising a DC/DC converter operatively connected to the load balancer, where the DC/DC converter is adapted to be operatively connected to the at least one DC power source.

6. A power supply as recited in claim 1, in which at least a portion of the load balancer is included in a DC/DC converter, in which the balance circuit is alternately connected between first and second split rail capacitors at a frequency and duty cycle that substantially matches a frequency and duty cycle of the DC/DC converter.

7. A power supply as recited in claim 1, in which the load balancer comprises a balance circuit that is alternately connected between first and second split rail capacitors such that the load balancer operates with nearly zero voltage switching.

8. A power supply as recited in claim 1, in which the DC bus is adapted to be connected to a plurality of DC power sources.

9. A power supply as recited in claim 1, in which the AC bus is adapted to be connected to at least one AC power source.

10. A power supply configured to operatively connect at least one load to a plurality of DC power sources, the power supply comprising:

an AC bus adapted to be operatively connected to the load;

a DC bus;

a DC/AC converter operatively connected between the DC bus and the AC bus; and

a first DC/DC converter operatively connected between a first DC power source and the DC bus;

a second DC/DC converter operatively connected to a second DC power source;

a load balancer operatively connected between the second DC/DC converter and the DC bus;

wherein

the power supply supplies power to the load

from the first DC power source through the first DC/DC converter, the DC bus, the DC/AC converter, and the AC bus, and

from the second DC power source through the second DC/DC converter, the load balancer, the DC bus, the DC/AC converter, and the AC bus.

11. A power supply as recited in claim 10, in which the load balancer substantially equalizes the charge on first and second split rail capacitors.

12. A power supply as recited in claim 10, in which the load balancer comprises a resonant capacitor and a resonant inductor connected in series.

13. A power supply as recited in claim 10, in which load balancer comprises a balance circuit that is alternately connected between first and second split rail capacitors.

14. A power supply as recited in claim 10, in which the load balancer comprises a balance circuit that is alternately connected between first and second split rail capacitors such that the load balancer operates with nearly zero voltage switching.

15. A power supply as recited in claim 10, in which the AC bus is adapted to be connected to at least one of a plurality of AC power sources.

16. A method of operatively connecting at least one load to at least one DC power source, the method comprising the steps of:

operatively connecting an AC bus to the load;

operatively connecting a DC/AC converter between a DC bus and the AC bus;

operatively connecting a load balancer between at least one DC power source and the DC bus;

supplying power to the load from the first DC power source through the load balancer, the DC bus, the DC/AC converter, and the AC bus.

17. A method as recited in claim 16, further comprising the step of arranging the load balancer to substantially equalize the charge on first and second split rail capacitors.

18. A method as recited in claim 16, in which the step of operatively connecting the load balancer comprises the step of connecting a resonant capacitor and a resonant inductor in series.

19. A method as recited in claim 16, in which the step of operatively connecting the load balancer comprises the step of alternately connecting a balance circuit between first and second split rail capacitors.

20. A method as recited in claim 16, further comprising the step of operatively connecting a DC/DC converter between the load balancer and to at least one DC power source.

21. A method as recited in claim 16, further comprising the step of including at least a portion of the load balancer in a DC/DC converter such that the balance circuit is alternately connected between first and second split rail capacitors at a frequency and duty cycle that substantially matches a frequency and duty cycle of the DC/DC converter.

22. A method as recited in claim 16, in which the step of operatively connecting load balancer comprises the step of alternately connecting a balance circuit between first and second split rail capacitors such that the load balancer operates with nearly zero voltage switching.

23. A method as recited in claim 16, further comprising the step of operatively connecting the AC bus to at least one AC power source.