Programmable inverter for controllable grid response

• US 10,447,040 B2
• Filed: 10/15/2014
• Issued: 10/15/2019
• Est. Priority Date: 10/15/2014
• Status: Active Grant

• Current Assignee: Cummins Power Generation IP, Inc.
• Original Assignee: Cummins Power Generation IP, Inc.
• Inventors: Ayana, Elias M., Hunt, Michelle, Palmer, Brad K.
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Dominique, Emmanuel
• Application Number:
  US14/515,108
• Publication Number:
  US 20160111879A1
• Time in Patent Office: 1,826 Days
• CPC Class Codes: H02J 2300/10 The dispersed energy generation being of fossil origin, e.g. diesel generators
• CPC Class Codes: H02J 3/18 Arrangements for adjusting, eliminating or compensating reactive power in networks for adjustment of voltage H02J3/16
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/40 Synchronising a generator for connection to a network or to another generator
• CPC Class Codes: H02J 3/48 Controlling the sharing of the in-phase component
• CPC Class Codes: H02M 5/458 using semiconductor devices only
• CPC Class Codes: H02P 9/04 Control effected upon non-electric prime mover and dependent upon electric output value of the generator
• CPC Class Codes: H02P 9/08 Control of generator circuit during starting or stopping of driving means, e.g. for initiating excitation

Abstract

A system for providing programmable grid response characteristics includes a generator set having an alternator output voltage, where the alternator output voltage is rectified to provide DC power to a DC bus of the generator set. The system further includes a programmable inverter having power electronics configured to receive a response requirement corresponding to a code requirement of a grid, receive the DC power from the DC bus, and condition the DC power based on the response requirement to provide an AC output response. The AC output response meets specifications of the response requirement.

Claims

1. A system for providing programmable grid response characteristics, comprising:

a generator set having an alternator output voltage, wherein the alternator output voltage is rectified to provide DC power to a DC bus of the generator set; and

a programmable inverter comprising power electronics configured to;

store a plurality of differing response requirements each corresponding to one of a plurality of differing grid code requirements of a plurality of grids, each of the differing grid code requirements relating to compliance requirements of a jurisdiction for connecting to one of the plurality of grids,

select a response requirement from the plurality of response requirements, the selected response requirement corresponding to a grid code requirement of a first grid to which the system is connected or is to be connected from among the plurality of grids,

receive the DC power from the DC bus, and

condition the DC power based on the selected response requirement to provide an AC output response, wherein the AC output response meets specifications of the selected response requirement.

2. The system of claim 1, wherein the grid code requirement is based on a low voltage ride through (LVRT) output requirement.

3. The system of claim 1, wherein the selected response requirement is based on one of a target country, a target location, a target grid code response or a target generator set mode of operation of the programmable inverter.

4. The system of claim 3, wherein the selected response requirement is based on the target location of the AC output response of the programmable inverter.

5. The system of claim 1, wherein the programmable inverter is configured to update the selected response requirement responsive to a code change or other output response update.

6. The system of claim 1, wherein the system is on a microgrid of a grid, and wherein the programmable inverter is configured to function in an island mode for the microgrid.

7. The system of claim 6, wherein while in the island mode the programmable inverter is configured to provide a grid reference for one or more additional grid following inverters on the microgrid.

8. The system of claim 1, further comprising one or more additional DC sources coupled to the DC bus, wherein the one or more additional DC sources are configured to allow for a load surge capacity by providing additional DC power.

9. The system of claim 8, wherein the one or more additional DC sources are one or more storage devices and the generator set is sized based on the additional DC power and an expected average load of the generator set.

10. The system of claim 1, further comprising an active rectifier stage configured to boost DC voltage of the DC bus to allow a prime mover of the generator set to operate at a reduced operating speed or reduced power output setting.

11. The system of claim 1, further comprising a battery coupled to the DC bus and configured to provide power to the grid when power of the generator set is cycled off.

12. The system of claim 1, wherein the generator set is configured to support a gradual start-up upon connection of a load.

13. The system of claim 1, wherein the programmable inverter is configured to receive commands and modify a response of the programmable inverter based on the commands during operation.

14. The system of claim 1, wherein the programmable inverter is configured to decouple an AC transient response of the programmable inverter from a transient response of at least one of a prime mover or an alternator of the generator set.

15. The system of claim 1, wherein the generator set is configured to provide a low RPM spinning reserve mode when a load is not connected to the generator set, and wherein the generator set is configured to spool up out of the low RPM spinning reserve mode upon connection of the load.

16. The system of claim 1, wherein the system further comprises a plurality of generator sets and a plurality of programmable inverters, wherein the generator set is one of the plurality of generator sets and the programmable inverter is one of the plurality of programmable inverters, each of the plurality of generator sets coupled to one of the plurality of programmable inverters.

17. The system of claim 16, wherein at least one of the plurality of generator sets and at least one of the plurality of programmable inverters are configured to be hot swappable on to a common DC bus.

18. The system of claim 16, wherein the plurality of generator sets and the plurality of programmable inverters are coupled to a common DC bus in a DC parallel configuration.

19. The system of claim 16, wherein the plurality of programmable inverters are coupled to a common local grid in an AC parallel configuration.

20. The system of claim 16, wherein each of the plurality of programmable inverters is configured to provide an equal AC output response to a load.

21. The system of claim 20, further comprising a controller configured to control the plurality of programmable inverters, and wherein each of the plurality of programmable inverters is configured to provide an AC output response as controlled by the controller.

22. The system of claim 21, wherein the controller is configured to control the plurality of programmable inverters to reduce a fuel consumption across the plurality of generator sets.

23. The system of claim 21, wherein the controller is configured to control the plurality of programmable inverters to provide a stable combined power output level across the plurality of generator sets.

24. A method of providing programmable grid response characteristics, comprising:

providing, by a generator set, an alternator output voltage;

rectifying the alternator output voltage to provide DC power to a DC bus of the generator set;

selecting, by a programmable inverter comprising power electronics, a response requirement from a plurality of differing response requirements stored in the programmable inverter, each of the plurality of differing response requirements corresponding to one of a plurality of differing grid code requirements of a plurality of grids, each of the differing grid code requirements relating to compliance requirements of a jurisdiction for connecting to one of the plurality of grids, wherein the selected response requirement corresponds to a grid code requirement of a grid to which the programmable inverter is connected or is to be connected;

receiving, by the programmable inverter, the DC power from the DC bus; and

conditioning, by the programmable inverter, the DC power based on the selected response requirement to provide an AC output response, wherein the AC output response meets specifications of the selected response requirement.

25. The method of claim 24, wherein the grid code requirement is based on a low voltage ride through (LVRT) output requirement.

26. The method of claim 24, wherein the selected response requirement is based on a target location or target grid code of the AC output response of the programmable inverter.

27. The method of claim 24, further comprising updating the selected response requirement responsive to a code change or other output response update.

28. The method of claim 24, further comprising:

coupling one or more additional DC sources couple to the DC bus; and

providing additional DC power, by the one or more additional DC sources, to the programmable inverter.

29. The method of claim 28, wherein the additional DC sources are storage devices and further comprising sizing the generator set based on the additional DC power, a required load surge capacity, and an expected average load of the generator set.

30. The method of claim 24, further comprising boosting, by an active rectifier stage, DC voltage of the DC bus to allow a prime mover of the generator set to operate at a reduced operating speed or reduced power output setting.

31. The method of claim 24, further comprising operating the generator set in a fall back power generation mode by disconnecting the programmable inverter and connecting the alternator output voltage directly to a grid to output voltage directly to the grid as a synchronous generator.

32. The method of claim 24, further comprising anticipating a load surge, wherein anticipating the load surge comprises:

keeping, by the programmable inverter, the AC output response stable and;

allowing a prime mover of the generator set to increase in rotational speed and store energy in response to the increased rotational speed of the prime mover.

33. The method of claim 24, further comprising utilizing the generator set as a replacement for an uninterruptible power supply in a data center.

34. The method of claim 24, further comprising coupling the generator set to a renewable energy source configured to utilize the generator set to supplement power generated by the renewable energy source.

35. A system for providing programmable grid response characteristics, comprising:

a generator set configured to generate and output AC power;

a rectifier coupled to the generator set and configured to;

receive the AC power, and

convert the AC power into DC power; and

one or more inverters coupled to the rectifier, each inverter comprising;

a transceiver configured to receive a transmitted response requirement corresponding to a grid code requirement of a grid;

programmable power electronics configured to;

store a plurality of differing response requirements each corresponding to one of a plurality of differing grid code requirements of a plurality of grids, each of the differing grid code requirements relating to compliance requirements of a jurisdiction for connecting to one of the plurality of grids,

select a response requirement from the plurality of response requirements, the selected response requirement corresponding to a grid code requirement of a first grid to which the system is connected or is to be connected from among the plurality of grids,

receive the DC power, and

condition, as specified by the selected response requirement, the DC power to provide an AC output response, wherein the AC output response is formed according to specifications of the selected response requirement; and

one or more processors configured to;

analyze the selected response requirement to determine the specifications of the selected response requirement, and

control operation of the programmable power electronics to convert the DC power to the AC output response based on the selected response requirement.

36. The system of claim 35, wherein the one or more processors are further configured to:

receive, via the transceiver, a code update or other output response update, and

update the selected response requirement responsive to the received update.

37. The system of claim 35, wherein the grid code requirement specifies a low voltage ride through (LVRT) output requirement.

38. The system of claim 37, wherein the selected response requirement is based on a target location or target grid code of the AC output response.

39. The system of claim 38, wherein the rectifier comprises an active rectifier stage configured to boost the DC power to allow a prime mover of the generator set to operate at a reduced operating speed or reduced power output setting.

40. The system of claim 39, wherein the generator set is a variable speed genset, and wherein the AC output response is conditioned to match a particular load.

41. The system of claim 40, further comprising one or more DC sources coupled to a DC bus of the system, the one or more DC sources configured to allow for one or more of lower AC power output of the generator set or a load surge capacity by providing additional DC power.

42. The system of claim 35, wherein:

the programmable power electronics are further configured to condition, as specified by the selected response requirement, the DC power to provide a second AC output response, wherein the second AC output response is formed according to the specifications of the selected response requirement; and

the one or more processors are further configured to control operation of the programmable power electronics to convert the DC power to the second AC output response based on the selected response requirement.