Methods, systems, and computer readable media for protecting and controlling a microgrid with a dynamic boundary

Patent metadata

Field	Value
Publication number	US-11515702-B2
Application number	US-202016775836-A
Country	US
Kind code	B2
Filing date	Jan 29, 2020
Priority date	May 1, 2019
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

Methods, systems, and computer readable mediums for protecting and controlling a microgrid with a dynamic boundary are disclosed. One method includes detecting a fault in a microgrid that includes a dynamic point-of-common-coupling (PCC), in response to determining that the microgrid is operating in a grid-connected mode, isolating the fault by tripping a microgrid side smart switch and a grid side smart switch that are located immediately adjacent to the fault, initiating the reclosing of the grid side smart switch, and initiating the reclosing for the microgrid side smart switch via resynchronization if the grid side smart switch is successfully reclosed, and in response to determining that the microgrid is operating in an islanded mode, isolating the fault by tripping a microgrid side smart switch that is located immediately adjacent to the fault, and initiating the reclosing of the microgrid side smart switch.

First claim

What is claimed is:

1. A method for protecting and controlling a microgrid with a dynamic boundary, the method comprising:
detecting a fault in a microgrid that includes a dynamic point-of-common-coupling (PCC);
in response to determining that the microgrid is operating in a grid-connected mode, isolating the fault by tripping a microgrid side smart switch and a grid side smart switch that are located immediately adjacent to the fault, wherein each of the microgrid side smart switch and the grid side smart switch is equipped with a directional element that determines the position of the fault, initiating a reclosing of the grid side smart switch, and initiating the reclosing for a microgrid side smart switch via resynchronization if the grid side smart switch is successfully reclosed; and
in response to determining that the microgrid is operating in an islanded mode, isolating the fault by tripping a microgrid side smart switch that is located immediately adjacent to the fault, wherein the microgrid side smart switch is equipped with a directional element that determines the position of the fault, and initiating the reclosing of the microgrid side smart switch.

2. The method of claim 1 wherein the smart switches in the microgrid are configured to communicate with each other.

3. The method of claim 1 wherein the microgrid side smart switch determines a trip decision using an undervoltage relay and/or overvoltage relay included in the microgrid side smart switch.

4. The method of claim 1 wherein the grid side smart switch determines a trip decision using an inverse time overcurrent relay included in the grid side smart switch.

5. The method of claim 1 wherein the grid side smart switch sends a notification signal to a microgrid central controller (MGCC) when the grid side smart switch is successfully reclosed.

6. The method of claim 5 wherein the MGCC receives a subsequent notification signal when the fault is cleared.

7. The method of claim 1 wherein the microgrid includes a microgrid central controller (MGCC) that redefines a microgrid side and/or a main grid side after feeder reconfiguration.

8. The method for claim 1 wherein the microgrid includes at least one distributed energy resource (DER) with ride-through capability.

9. A system for protecting and controlling a microgrid with a dynamic boundary, the system comprising:
a microgrid central controller (MGCC) and smart switches configured for detecting and isolating a fault in a microgrid, wherein the microgrid includes a dynamic point-of-common-coupling (PCC); and
a plurality of protective relays that are configured for:
in response to a determination that the microgrid is operating in a grid-connected mode, isolating the fault by tripping a microgrid side smart switch and a grid side smart switch that are located immediately adjacent to the fault, wherein each of the microgrid side smart switch and the grid side smart switch is equipped with a directional element that determines the position of the fault, initiating a reclosing of the grid side smart switch, and initiating a reclosing for the microgrid side smart switch via resynchronization if the grid side smart switch is successfully reclosed; and
in response to a determination that the microgrid is operating in an islanded mode, isolating the fault by tripping a microgrid side smart switch that is located immediately adjacent to the fault, wherein the microgrid side smart switch is equipped with a directional element that determines the position of the fault, and initiating the reclosing of the microgrid side smart switch.

10. The system of claim 9 wherein the plurality of protective relays are incorporated in a plurality of smart switches that are configured to communicate with each other.

11. The system of claim 9 wherein the microgrid side smart switch determines a trip decision using an undervoltage relay and/or an undervoltage relay included in the microgrid side smart switch.

12. The system of claim 9 wherein the grid side smart switch determines a trip decision using an inverse time overcurrent relay included in the grid side smart switch.

13. The system of claim 9 wherein the grid side smart switch sends a notification signal to the MGCC when the grid side smart switch is successfully reclosed.

14. The system of claim 13 wherein the MGCC receives a subsequent notification signal when the fault is cleared.

15. The system of claim 9 wherein the MGCC redefines a microgrid side and/or a main grid side after feeder reconfiguration.

16. The system of claim 9 wherein the microgrid include at least one distributed energy resource (DER) with ride-through capability.

17. A non-transitory computer readable medium having stored thereon executable instructions that when executed by a processor of a computer controls the computer to perform steps comprising:
detecting a fault in a microgrid that includes a dynamic point-of-common-coupling (PCC);
in response to determining that the microgrid is operating in a grid-connected mode, isolating the fault by tripping a microgrid side smart switch and a grid side smart switch that are located immediately adjacent to the fault, wherein each of the microgrid side smart switch and the grid side smart switch is equipped with a directional element that determines the position of the fault, initiating a reclosing of the grid side smart switch, and initiating a reclosing for the microgrid side smart switch via resynchronization if the grid side smart switch is successfully reclosed; and
in response to determining that the microgrid is operating in an islanded mode, isolating the fault by tripping a microgrid side smart switch that is located immediately adjacent to the fault, wherein the microgrid side smart switch is equipped with a directional element that determines the position of the fault, and initiating the reclosing of the microgrid side smart switch.

18. The non-transitory computer readable medium of claim 17 wherein the microgrid side smart switch determines a trip decision using an undervoltage relay and/or overvoltage relay included in the microgrid side smart switch.

19. The non-transitory computer readable medium of claim 17 wherein the grid side smart switch determines a trip decision using an inverse time overcurrent relay included in the grid side smart switch.

20. The non-transitory computer readable medium of claim 17 wherein the microgrid includes a microgrid central controller (MGCC) that redefines a microgrid side and/or a main grid side after feeder reconfiguration.

Assignees

• Univ Tennessee Res Found

Inventors

• Wang Fei
• Li Dingrui
• Liu Yilu
• Ma Yiwei
• Ray Ishita
• Tolbert Leon M
• Yin He
• Zhu Lin

Classifications

• H02J13/13

  characterised by the transmission of data to equipment in the power network · CPC title

• H02J2101/40

  Hybrid power plants, i.e. a plurality of different generation technologies being operated at one power plant · CPC title

• H02J13/36

  specially adapted for protection systems · CPC title

• H02J13/14

  the power network being locally controlled, e.g. home energy management systems [HEMS] · CPC title

• H02H7/28

  for meshed systems · CPC title