Parallel electric arc detection across the main terminals of a photovoltaic installation

• US 9,843,288 B2
• Filed: 08/27/2014
• Issued: 12/12/2017
• Est. Priority Date: 08/29/2013
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Chaintreuil, Nicolas, Plissonnier, Alexandre
• Primary Examiner(s): Tang, Minh N
• Application Number:
  US14/915,504
• Publication Number:
  US 20160218669A1
• Time in Patent Office: 1,203 Days
• CPC Class Codes: G01R 31/26 Testing of individual semiconductor devices testing or measuring during manufacture or treatment H01L22/00; testing of photovoltaic devices H02S50/10
• CPC Class Codes: H02S 50/00 Monitoring or testing of PV systems, e.g. load balancing or fault identification
• CPC Class Codes: H02S 50/10 Testing of PV devices, e.g. of PV modules or single PV cells testing of semiconductor devices during manufacturing H01L22/00
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

A method detecting a parallel arc in a photovoltaic device, including N (N=1 or N>1) photovoltaic modules, connected to a charge device having a capacitive behavior for the modules, the method including: a) detecting, across main terminals of the device, evolution of voltage over time, at least during formation of the electric arc; b) identifying a negative voltage variation between a first zone with stable voltage and a second zone with stable voltage for a duration of at least 5 μs, which immediately follows the voltage variation, and c) determining whether the voltage variation is between a maximum value Vmax, greater than or equal to 100 V, and a minimum value Vmin, less than or equal to 30 V, with a fall time of this variation between a minimum duration Tmin greater than or equal to 0.01 μs and a maximum duration Tmax less than or equal to 10 μs.

Claims

1. A method for detecting a parallel arc in a photovoltaic device, including N (N=1 or N>

1) photovoltaic modules, connected to a charge device having a capacitive behavior for the modules, the method comprising;

a) detecting, by a detector and across main terminals of the photovoltaic device, evolution of voltage over time;

b) identifying, by a data processor, a negative voltage variation between a first zone, during which the voltage has a substantially stable slope and a second zone, during which the voltage has a substantially stable slope for a duration of at least 5 μ

s, which immediately follows the voltage variation; and

c) determining, by the data processor, whether the voltage variation is between a maximum value Vmax, greater than or equal to 100 V, and a minimum value Vmin, less than or equal to 30 V, with a fall time of this variation between a minimum duration Tmin greater than or equal to 0.01 μ

s and a maximum duration Tmax less than or equal to 10 μ

s.

2. The method according to claim 1, wherein the determining c) takes place:

by analyzing the slope of the voltage variation and determining whether this slope is between;

a minimum value, given by the ratio of Vmin/Tmax,

and a maximum value, given by the ratio of Vmax/Tmin;

and, by determining whether the voltage variation is between a minimum value Vmin, less than or equal to 30 V, and a maximum value Vmax, greater than or equal to 100 V, or whether a rise time of the variation is between a minimum duration Tmin greater than or equal to 0.01 μ

s and a maximum duration Tmax less than or equal to 10 μ

s.

3. The method according to claim 1, wherein passive and/or active filtering of the evolution of the voltage over time takes place.

4. The method according to claim 1, wherein the evolution of the voltage over time is digitized, whereby the a) to c) are performed based on digital voltage values.

5. The method according to claim 1, wherein the charge device includes a converter, an inverter, or a battery.

6. The method according to claim 1, wherein a current in the photovoltaic device is a direct current.

7. A device for detecting a parallel arc in a photovoltaic device, including N (N=1 or N>

1) photovoltaic modules, connected to a charge device having a capacitive behaviour for the modules, the device comprising;

a) means for detecting, across main terminals of the photovoltaic device, evolution of voltage over time;

b) means for identifying a negative voltage variation between a first zone, during which the voltage has a substantially stable slope and a second zone, during which the voltage has a substantially stable slope for a duration of at least 5 μ

s, which immediately follows the voltage variation; and

c) means for determining whether the voltage variation is between a maximum value Vmax, greater than or equal to 100 V, and a minimum value Vmin, less than or equal to 30 V, with a fall time of the variation between a minimum duration Tmin greater than or equal to 0.01 μ

s and a maximum duration Tmax less than or equal to 10 μ

s.

8. The device according to claim 7, wherein the means for determining determines whether the voltage variation is between the maximum value Vmax and the minimum value Vmin, with a fall time for the variation of between Tmin and Tmax:

by analyzing the slope of the voltage variation and determining whether the slope is between;

a minimum value, given by the ratio of Vmin/Tmax,

and a maximum value, given by the ratio of Vmax/Tmin;

and, by determining whether the voltage variation is between a minimum value Vmin, less than or equal to 30 V, and a maximum value Vmax, greater than or equal to 100 V, or whether a rise time of the variation is between a minimum duration Tmin greater than or equal to 0.01 μ

s and a maximum duration Tmax less than or equal to 10 μ

s.

9. The device according to claim 7, further comprising means for removing frequencies at least equal to 100 Hz from the evolution of the voltage over time.

10. The device according to claim 7, further comprising means for passive and/or active filtering of the evolution of the voltage over time.

11. The device according to claim 7, further comprising means for analog and digital filtering of the evolution of the voltage over time.

12. The device according to claim 7, further comprising means for digitizing voltages measured.

13. The device according to claim 7, wherein the charge device having a capacitive behaviour for the modules includes a converter, an inverter, or a battery.

14. A device for detecting a parallel arc in a photovoltaic device, including N (N=1 or N>

1) photovoltaic modules, connected to a charge device having a capacitive behaviour for the modules, the device comprising;

a) a detector to detect, across main terminals of the photovoltaic device, evolution of voltage over time;

b) a data processor configured to;

identify a negative voltage variation between a first zone, during which the voltage has a substantially stable slope and a second zone, during which the voltage has a substantially stable slope for a duration of at least 5 μ

s, which immediately follows the voltage variation, and

determine whether the voltage variation is between a maximum value Vmax, greater than or equal to 100 V, and a minimum value Vmin, less than or equal to 30 V, with a fall time of this variation between a minimum duration Tmin greater than or equal to 0.01 μ

s and a maximum duration Tmax less than or equal to 10 μ

s.

15. The device according to claim 14, wherein the data processor determines whether the voltage variation is between the maximum value Vmax and the minimum value Vmin, with a fall time for the variation of between Tmin and Tmax:

by analyzing the slope of the voltage variation and determining whether this slope is between;

a minimum value, given by the ratio of Vmin/Tmax,

and a maximum value, given by the ratio of Vmax/Tmin;

and, by determining whether the voltage variation is between a minimum value Vmin, less than or equal to 30 V, and a maximum value Vmax, greater than or equal to 100 V, or whether a rise time of the variation is between a minimum duration Tmin greater than or equal to 0.01 μ

s and a maximum duration Tmax less than or equal to 10 μ

s.

16. The device according to claim 14, further comprising at least a filter removing frequencies at least equal to 100 Hz from the evolution of the voltage over time.

17. The device according to claim 14, further comprising at least one of a passive and active filter to filter the evolution of the voltage over time.

18. The device according to claim 14, further comprising at least one of an analog and digital filter to filter the evolution of the voltage over time.

19. The device according to claim 14, further comprising a converter to digitize the evolution of the voltage over time.

20. The device according to claim 14, wherein the charge device having a capacitive behavior for the modules includes a converter, an inverter, or a battery.