Method for detecting an electric arc in a photovoltaic installation

Patent metadata

Field	Value
Publication number	US-9389272-B2
Application number	US-200913141598-A
Country	US
Kind code	B2
Filing date	Dec 21, 2009
Priority date	Dec 22, 2008
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

Method for detecting an electric are in a photovoltaic device by ultrasound, comprising measuring at least one parameter among the amplitude, the duration and the central frequency, of an electrical signal received by an ultrasound sensor; and comparing the measurement of this at least one parameter of the electrical signal with predefined values in order to determine whether the measurement corresponds to that of an electric arc.

First claim

The invention claimed is:

1. A method for detecting an electric arc by ultrasound the method comprising the steps of:
positioning at least one ultrasound sensor on a photovoltaic module or on a chassis supporting a plurality of photovoltaic modules;
measuring (E 1 ) at least one parameter among an amplitude, a duration and a central frequency of an electrical signal received by the ultrasound sensor;
comparing (E 2 ) the measurement of this at least one parameter of the electrical signal with predefined values in order to determine whether the measurement corresponds to that of an electric arc,
wherein the second step (E 2 ) of comparing the measurement of the at least one parameter with predefined values comprises the following checks for determining whether the electrical signal is actually generated by an electric arc:
checking (E 21 ) whether the amplitude of the electrical signal is greater than or equal to 40 dB; and/or
checking (E 22 ) whether the duration of the electrical signal lies between 15 and 25 μs; and/or
checking (E 23 ) whether the central frequency of the electrical signal lies between 200 and 360 kHz,

checking (E 24 ) whether rms voltage of the electrical signal increases from a first value of between 5 and 15 dB EA to a second value of between 15 and 25 dB EA .

2. The method of claim 1 , comprising linking the at least one ultrasound sensor to a processing unit.

3. The method of claim 1 , wherein the at least one ultrasound sensor for the detection of electric arcs is located on a frame or on glass of at least one of the plurality of photovoltaic modules.

4. The method of claim 1 , wherein the plurality of photovoltaic modules are mounted on one or more chassis.

5. The method of claim 4 , wherein there is at least one ultrasound sensor per two photovoltaic modules.

6. A method for safeguarded management of a photovoltaic device, the method comprising the steps of:
positioning at least one ultrasound sensor on a photovoltaic module or on a chassis supporting a plurality of photovoltaic modules;
measuring (E 1 ) at least one parameter among an amplitude, a duration and a central frequency of an electrical signal received by the ultrasound sensor;
comparing (E 2 ) the measurement of this at least one parameter of the electrical signal with predefined values in order to determine whether the measurement corresponds to that of an electric arc,
wherein the second step (E 2 ) of comparing the measurement of the at least one parameter with predefined values comprises the following checks for determining whether the electrical signal is actually generated by an electric arc:
checking (E 21 ) whether the amplitude of the electrical signal is greater than or equal to 40 dB; and/or
checking (E 22 ) whether the duration of the electrical signal lies between 15 and 25 μs; and/or
checking (E 23 ) whether the central frequency of the electrical signal lies between 200 and 360 kHz;

opening an electrical circuit (E 3 ) of the photovoltaic device in the event that an electric arc is detected, in order to extinguish the electric arc,
after opening the electrical circuit following the detection of an electric arc, putting the photovoltaic device back into operation at least once (E 4 );
if an electric arc is detected again, stopping operation of the photovoltaic device and transmitting information about the malfunction of the photovoltaic device (E 5 ).

7. The method of claim 6 , comprising opening the electrical circuit with a safety device in the event that an electric arc is detected.

8. The method of claim 7 , wherein the safety device is positioned on an output terminal of all or some of the plurality of photovoltaic modules.

9. A method for safeguarded management of a photovoltaic device, the method comprising the steps of:
positioning at least one ultrasound sensor on a photovoltaic module or on a chassis supporting a plurality of photovoltaic modules;
measuring (E 1 ) at least one parameter among an amplitude, a duration and a central frequency of an electrical signal received by the ultrasound sensor;
comparing (E 2 ) the measurement of this at least one parameter of the electrical signal with predefined values in order to determine whether the measurement corresponds to that of an electric arc,
wherein the second step (E 2 ) of comparing the measurement of the at least one parameter with predefined values comprises the following checks for determining whether the electrical signal is actually generated by an electric arc:
checking (E 21 ) whether the amplitude of the electrical signal is greater than or equal to 40 dB; and/or
checking (E 22 ) whether the duration of the electrical signal lies between 15 and 25 μs; and/or
checking (E 23 ) whether the central frequency of the electrical signal lies between 200 and 360 kHz;

opening an electrical circuit (E 3 ) of the photovoltaic device in the event that an electric arc is detected, in order to extinguish the electric arc,
locating (E 6 ) the electric arc in the photovoltaic device, the step (E 6 ) of locating the electric arc in the photovoltaic device comprising the following substeps:
storing reception times (ti) of the electric arc for each of sensors ( 16 i ) and ranking these sensors in order of reception (E 61 , E 62 );
determining the location of the electric arc as a function of the order of arrival of the electric arc at each sensor ( 16 i ) (E 63 ).

10. A method for safeguarded management of a photovoltaic device according to claim 9 , wherein the method comprises a preliminary step (E 0 ) of initiating the electric arc detection method only after the photovoltaic device exceeds a certain electrical production threshold.

11. Method for detecting an electric arc by ultrasound, the method comprising the steps of:
positioning at least one ultrasound sensor on a photovoltaic module or on a chassis supporting a plurality of photovoltaic modules;
measuring (E 1 ) at least one parameter among an amplitude, a duration and a central frequency of an electrical signal received by the ultrasound sensor;
comparing (E 2 ) the measurement of this at least one parameter of the electrical signal with predefined values in order to determine whether the measurement corresponds to that of an electric arc,
wherein the second step (E 2 ) of comparing the measurement of the at least one parameter with predefined values comprises the following checks for determining whether the electrical signal is actually generated by an electric arc:
checking (E 21 ) whether the amplitude of the electrical signal is greater than or equal to 40 dB; and
checking (E 23 ) whether the central frequency of the electrical signal lies between 200 and 360 kHz.

12. The method of claim 11 , wherein the second step (E 2 ) further comprises checking (E 22 ) whether the duration of the electrical signal lies between 15 and 25 μs.

Assignees

• Chaintreuil Nicolas
• Perichon Pierre
• Vallet Sandrine
• Commissariat Energie Atomique

Inventors

• Chaintreuil Nicolas
• Perichon Pierre
• Vallet Sandrine

Classifications

• H10F77/955

  for photovoltaic devices · CPC title

• H10F10/00

  Individual photovoltaic cells, e.g. solar cells (electrolytic light-sensitive devices, e.g. dye-sensitised solar cells, H01G9/20) · CPC title

• H02H7/20

  for electronic equipment (for converters H02H7/10; for electric measuring instruments G01R1/36; for DC voltage or current semiconductor regulators G05F1/569; for amplifiers H03F1/52; for electronic switching circuits H03K17/08) · CPC title

• H02H1/0015

  Using arc detectors · CPC title

• H01L31/02021

  Electricity · mapped topic