System and method for synchronizing multiple generators with an electrical power distribution system

• US 9,136,711 B2
• Filed: 04/04/2012
• Issued: 09/15/2015
• Est. Priority Date: 08/21/2007
• Status: Active Grant

• Current Assignee: EI Electronics LLC (Hubbell, Inc.)
• Original Assignee: Electro Industries/Gaugetech
• Inventors: Slota, Frederick B., Kagan, Erran
• Primary Examiner(s): Fennema, Robert
• Assistant Examiner(s): Norton, Jennifer L
• Application Number:
  US13/439,333
• Publication Number:
  US 20120187770A1
• Time in Patent Office: 1,259 Days
• Field of Search: 700/286, 700/287, 700/297, 307/87, 322/29, 323/212, 323/235, 323/244
• US Class Current: 1/1
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05B 23/02 Electric testing or monitoring
• CPC Class Codes: G05F 1/625 wherein it is irrelevant whether the variable actually regulated is ac or dc
• CPC Class Codes: G05F 1/66 Regulating electric power
• CPC Class Codes: H02J 13/00009 using pulsed signals
• CPC Class Codes: H02J 3/06 Controlling transfer of power between connected networks; Controlling sharing of load between connected networks
• CPC Class Codes: H02J 3/08 Synchronising of networks
• CPC Class Codes: H02J 3/34 Arrangements for transfer of electric power between networks of substantially different frequency
• 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 3/40 Synchronising a generator for connection to a network or to another generator
• CPC Class Codes: H02J 3/42 with automatic parallel connection when synchronisation is achieved
• CPC Class Codes: H05B 47/19 via wireless transmission
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 20/246 the system involving the remote operation of lamps or lighting equipment
• CPC Class Codes: Y04S 40/121 using the power network as support for the transmission

Abstract

Systems and method for synchronizing power generators with a power grid are provided. One system among various implementations includes a plurality of synchronization modules, wherein each synchronization module corresponds to one power generator. The synchronization modules are configured to output a control signal to adjust a frequency of the respective power generator to correspond with the frequency of the existing power grid. The system also includes a central controller in communication with the plurality of synchronization modules. The central controller is configured to determine a propagation delay with respect to each synchronization module. The propagation delay is a measure of time for a signal to propagate from the respective synchronization module to the central controller. The central controller is further configured to send a control signal to each synchronization module to control when each synchronization module connects the respective power generator to the existing power grid.

Claims

1. A system comprising:

a plurality of power generators configured to be connected to transmission lines of an existing power grid;

a plurality of synchronization modules, each synchronization module corresponding to one of the plurality of power generators and configured to output a control signal to adjust a frequency of a respective power generator to correspond with the frequency of the existing power grid; and

a central controller in communication with the plurality of synchronization modules, the central controller configured to determine a propagation delay with respect to each synchronization module, the propagation delay being a measure of time for a signal to propagate from a respective synchronization module to the central controller;

wherein the central controller is further configured to send a control signal to each synchronization module to control when each synchronization module connects the respective power generator to the existing power grid based on the determined propagation delay signal.

2. The system of claim 1, further comprising a communication network, wherein the central controller communicates with the plurality of synchronization modules via the communication network.

3. The system of claim 2, wherein the communication network is configured to communicate with the plurality of synchronization modules via the existing power grid.

4. The system of claim 1, wherein the central controller is configured to determine the propagation delay using time signals synchronized using GPS signals.

5. The system of claim 1, wherein the central controller is further configured to transmit a request to obtain a status of each of the synchronization modules.

6. The system of claim 1, wherein each synchronization module is associated with a meter module configured to sense electrical parameters of an electrical power distribution system associated with the existing power grid.

7. The system of claim 6, wherein each synchronization module is further configured to compute a frequency of a voltage waveform of the respective power generator using zero-crossing times of the voltage waveform.

8. The system of claim 6, wherein each synchronization module is further configured to compute a phase angle difference between a voltage waveform of the respective power generator and the electrical power distribution system.

9. The system of claim 1, wherein the central controller is incorporated in one of the synchronization modules.

19. The system of claim 1, wherein the central controller is configured to determine the propagation delay using time signals synchronized using Precise Time Protocol.

20. The system of claim 8, wherein the computed phase angle difference is recorded with a timestamp.

21. The system of claim 20, wherein the timestamp is determined from a GPS signal.

22. The system of claim 20, wherein the timestamp is determined from an IRIG-B signal generating device coupled to each synchronization module.

23. The system of claim 2, wherein the communication network is configured to communicate with the plurality of synchronization modules via at least one of Ethernet lines, telephone lines, satellite transmission, cellular transmission and WiFi transmission.

24. The system of claim 1, wherein a time clock of the central controller and a time clock of each of the plurality of synchronization modules are synchronized using Precise Time Protocol.

45. The apparatus of claim 1, wherein the apparatus is selected from the group consisting of a digital electrical power and energy meter, a Programmable Logic Controller (PLC), a Remote Terminal Unit, a protective relay, or a fault recorder.

10. A method comprising:

associating a plurality of synchronization modules with a plurality of respective power generators;

outputting a control signal from each of the synchronization modules to adjust a frequency of the respective power generator to correspond with the frequency of an existing power grid;

determining a propagation delay with respect to each synchronization module, the propagation delay being a measure of time for a signal to propagate from the respective synchronization module to a central controller; and

sending a control signal from the central controller to each synchronization module to control when each synchronization module connects the respective power generator to the existing power grid based on the determined propagation delay signal.

11. The method of claim 10, wherein sending the control signal further comprises communicating through a communication network.

12. The method of claim 11, wherein sending the control signal further comprises communicating with the plurality of synchronization modules via the existing power grid.

13. The method of claim 10, further comprising determining the propagation delay using time signals synchronized using GPS signals.

14. The method of claim 10, further comprising transmitting a request to obtain the status of each of the synchronization modules.

15. The method of claim 10, further comprising sensing electrical parameters of an electrical power distribution system associated with the existing power grid.

16. The method of claim 15, further comprising computing a frequency of a voltage waveform of the respective power generator using zero-crossing times of the voltage waveform.

17. The method of claim 15, further comprising computing a phase angle difference between a voltage waveform of the respective power generator and the electrical power distribution system.

18. The method of claim 10, wherein sending the control signal to each of the synchronization modules further comprises staggering the control signals to prevent two power generators from being connected to the existing power grid at the same time.

25. The method of claim 10, further comprising determining the propagation delay using time signals synchronized using Precise Time Protocol.

26. The method of claim 17, further comprising recording a timestamp of the computed phase angle difference.

27. The method of claim 26, wherein the timestamp is determined from a GPS signal.

28. The method of claim 26, wherein the timestamp is determined from an IRIG-B signal generating device coupled to each synchronization module.

29. The method of claim 11, wherein sending the control signal further comprises communicating with the plurality of synchronization modules via at least one of Ethernet lines, telephone lines, satellite transmission, cellular transmission and WiFi transmission.

30. The method of claim 10, further comprising synchronizing a time clock of the central controller and a time clock of each of the plurality of synchronization modules using Precise Time Protocol.

31. An apparatus for synchronizing a plurality of power generators to transmission lines of an existing power grid, the apparatus comprising:

a controller in communication with a plurality of synchronization modules, each synchronization module corresponding to one of the plurality of power generators and configured to output a control signal to adjust a frequency of a respective power generator to correspond with the frequency of the existing power grid, the controller configured to determine a propagation delay with respect to each synchronization module, the propagation delay being a measure of time for a signal to propagate from a respective synchronization module to the controller;

wherein the controller is further configured to send a control signal to each synchronization module to control when each synchronization module connects the respective power generator to the existing power grid based on the determined propagation delay signal.

32. The apparatus of claim 31, further comprising a communication network, wherein the controller communicates with the plurality of synchronization modules via the communication network.

33. The apparatus of claim 32, wherein the communication network is configured to communicate with the plurality of synchronization modules via the existing power grid.

34. The apparatus of claim 31, wherein the controller is configured to determine the propagation delay using time signals synchronized using GPS signals.

35. The apparatus of claim 31, wherein the controller is further configured to transmit a request to obtain a status of each of the synchronization modules.

36. The apparatus of claim 31, further comprising a meter module configured to sense electrical parameters of an electrical power distribution system associated with the existing power grid.

37. The apparatus of claim 36, further comprising a synchronization module, the synchronization module configured to compute a frequency of a voltage waveform of the existing power grid using zero-crossing times of the voltage waveform.

38. The apparatus of claim 37, wherein the synchronization module is further configured to compute a phase angle difference between a voltage waveform of a respective power generator and the voltage waveform of the existing power grid.

39. The apparatus of claim 31, wherein the controller is configured to determine the propagation delay using time signals synchronized using Precise Time Protocol.

40. The apparatus of claim 38, wherein the voltage waveform of a respective power generator is received from at least one of the plurality of synchronization modules with a timestamp.

41. The apparatus of claim 40, wherein the timestamp is determined from a GPS signal.

42. The apparatus of claim 40, wherein the timestamp is determined from an IRIG-B signal generating device coupled to each synchronization module.

43. The apparatus of claim 32, wherein the communication network is configured to communicate with the plurality of synchronization modules via at least one of Ethernet lines, telephone lines, satellite transmission, cellular transmission and WiFi transmission.

44. The apparatus of claim 31, wherein a time clock of the controller and a time clock of each of the plurality of synchronization modules are synchronized using Precise Time Protocol.