System and method for arc detection and intervention in solar energy systems

Patent metadata

Field	Value
Publication number	US-9927822-B2
Application number	US-201514718426-A
Country	US
Kind code	B2
Filing date	May 21, 2015
Priority date	Feb 24, 2011
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

An arc detection and intervention system for a solar energy system. One or more arc detectors are strategically located among strings of solar panels. In conjunction with local management units (LMUs), arcs can be isolated and affected panels disconnected from the solar energy system.

First claim

What is claimed is:

1. A photovoltaic system, comprising:
a plurality of photovoltaic panels;
a plurality of devices locally coupled to the plurality of photovoltaic panels respectively, each respective device in the plurality of devices coupled to a respective photovoltaic panel of the plurality of photovoltaic panels, the respective device including:
a controller; and
a converter having at least one switch controlled by the controller to receive electricity generated by the respective photovoltaic panel and convert the electricity into an output;

a set of wires connecting outputs of the plurality of devices;
an arc detector coupled to the set of wires to detect arc occurrences; and
a system managing processor separate from a first device and in communication with the arc detector and the plurality of devices;
wherein the system managing processor is configured to identify a location of an arc in the photovoltaic system by at least:
communicating to the first device in the plurality of devices in the plurality of photovoltaic panels to turn off an output of the first device, and
determining absence of arc detected by the arc detector in a predetermined period of time after turning off the output of the first device; and

wherein an operation of the plurality of devices is controlled based on the location of the arc.

2. The system of claim 1 , wherein the arc detector is configured to detect an arc occurrence in the system via detecting a signal in the set of wires.

3. The system of claim 2 , wherein the signal corresponds to a voltage change.

4. The system of claim 2 , wherein the signal corresponds to a frequency spectrum change.

5. The system of claim 2 , wherein in response to a communication from the arc detector indicating a detected arc occurrence in the system, the system managing processor is configured to identify a subset of the plurality of devices.

6. The system of claim 5 , wherein the system managing processor is configured to instruct devices in the subset to turn off outputs for at least the predetermined period of time to determine whether the arc detector detects arc occurrences during a time period in which outputs of devices in the subset are turned off.

7. The system of claim 5 , wherein the system managing processor is configured to instruct devices in the subset to turn off outputs sequentially, wherein each of devices in the subset is instructed to turn off outputs for the predetermined period of time.

8. An apparatus, comprising:
a system managing processor for a photovoltaic system, the system having:
a plurality of photovoltaic panels;
a plurality of devices locally coupled to the plurality of photovoltaic panels respectively, each respective device in the plurality of devices coupled to a respective photovoltaic panel of the plurality of photovoltaic panels, the respective device including:
a controller; and
a converter having at least one switch controlled by the controller to receive electricity generated by the respective photovoltaic panel and convert the electricity into an output;

a set of wires connecting outputs of the devices; and
an arc detector coupled to the set of wires to detect arc occurrences; and

wherein the system managing processor is configured for communications with the arc detector and the devices in the photovoltaic system; and
wherein the system managing processor is configured to identify a location of an arc in the photovoltaic system by at least:
communicating to a first device in the plurality of devices in the plurality of photovoltaic panels to turn off an output of the first device, and
determining absence of arc detected by the arc detector in a predetermined period of time after turning off the output of the first device; and

wherein an operation of the plurality of devices is controlled based on the location of the arc.

9. The apparatus of claim 8 , wherein the arc detector is configured to detect an arc occurrence in the system via detecting a signal in the set of wires.

10. The apparatus of claim 9 , wherein the signal corresponds to a voltage change.

11. The apparatus of claim 9 , wherein the signal corresponds to a frequency spectrum change.

12. The apparatus of claim 9 , wherein in response to a communication from the arc detector indicating a detected arc occurrence in the system, the system managing processor is configured to identify a subset of the plurality of devices.

13. The apparatus of claim 12 , wherein the system managing processor is configured to instruct devices in the subset to turn off outputs for at least the predetermined period of time to determine whether the arc detector detects arc occurrences during a time period in which outputs of devices in the subset are turned off.

14. The apparatus of claim 12 , wherein the system managing processor is configured to instruct devices in the subset to turn off outputs sequentially, wherein each of devices in the subset is instructed to turn off outputs for the predetermined period of time.

15. A method in a photovoltaic system, the method comprising:
providing a plurality of photovoltaic panels and a plurality of devices locally coupled to the plurality of photovoltaic panels respectively, each respective device in the plurality of devices coupled to a respective photovoltaic panel of the plurality of photovoltaic panels, the respective device including:
a controller; and
a converter having at least one switch controlled by the controller to receive electricity generated by the respective photovoltaic panel and convert the electricity into an output, wherein a set of wires connect outputs of the devices; and

receiving, in a system managing processor of the photovoltaic system, a communication from an arc detector coupled to the set of wires, the communication indicating an arc occurrence detected by the arc detector; and
identifying, by the system managing processor, a location of an arc in the photovoltaic system by at least:
communicating to a first device in the plurality of devices in the plurality of photovoltaic panels to turn off an output of the first device, and
determining absence of arc detected by the arc detector in a predetermined period of time after turning off the output of the first device; and

wherein an operation of the plurality of devices is controlled based on the location of the arc.

16. The method of claim 15 , wherein the arc detector is configured to detect an arc occurrence in the system via detecting a signal in the set of wires.

17. The method of claim 16 , wherein the signal corresponds to one of: a voltage change, and a frequency spectrum change.

18. The method of claim 16 , further comprising:
in response to the communication from the arc detector, identifying, by the system managing processor a subset of the plurality of devices.

19. The method of claim 18 , further comprising:
communicating, by the system managing processor, with devices in the subset to turn off outputs for at least the predetermined period of time to determine whether the arc detector detects arc occurrences during a time period in which outputs of devices in the subset are turned off.

20. The method of claim 18 , wherein the system managing processor is configured to instruct devices in the subset to turn off outputs sequentially, wherein each of devices in the subset is instructed to turn off outputs for the predetermined period of time.

Assignees

• Tigo Energy Inc

Inventors

• Eizips Daniel
• Arditi Shmuel

Classifications

• H02S50/10

  Testing of PV devices, e.g. of PV modules or single PV cells (testing of semiconductor devices during manufacturing {H10P74/00}) · CPC title

• G05B15/02

  electric · CPC title

• H02S10/10

  including a supplementary source of electric power, e.g. hybrid diesel-PV energy systems (combinations with gas-turbine plants F02C6/00) · CPC title

• G05F1/02 Primary

  Regulating electric characteristics of arcs · CPC title

• G05B23/0218

  characterised by the fault detection method dealing with either existing or incipient faults · CPC title