System and method for detecting and locating an insulation flaw in a solar generator on a space vehicle

Patent metadata

Field	Value
Publication number	US-9506972-B2
Application number	US-201314136816-A
Country	US
Kind code	B2
Filing date	Dec 20, 2013
Priority date	Dec 21, 2012
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A system and method for detecting and locating an insulation flaw in a solar generator on a spacecraft. The solar generator comprises a plurality of flaps. Each flap bears at least one solar cell that is connected to an electrical distribution network and electrically insulated from the flap. Each flap is connected, by a first load and by a second load, to a first electrical line and a second electrical line, respectively. The ratio of the impedances of the first load and of the second load of a flap being denoted as an impedance ratio of the flap. The solar generator comprises at least two flaps exhibiting different respective impedance ratios. The system comprises a component for evaluating the currents flowing in the first and second electrical lines, and a detector for detecting and locating an insulation flaw in the solar generator based on the evaluations of the currents.

First claim

The invention claimed is:

1. A system for detecting and locating an insulation flaw, comprising:
a solar generator on a spacecraft comprising a plurality of flaps, each flap bearing at least one solar cell and being connected to a first electrical line by a first load and to a second electrical line by a second load, said at least one solar cell is connected to an electrical distribution network and said at least one solar cell is electrically insulated from said each flap such that current flows in the first and second electrical lines in response to an insulation flaw;
an evaluation component to evaluate currents flowing in the first electrical line and the second electrical line, respectively;
a detector to detect the insulation flaw in the solar generator based on evaluations of the currents flowing in at least one of the first electrical line and the second electrical line;
wherein a ratio of impedances of the first load and of the second load of a flap is denoted as an impedance ratio of the flap;
wherein the solar generator comprises at least two flaps exhibiting different respective impedance ratios; and
wherein the detector is configured to locate the detected insulation flaw by comparing the evaluations of the currents flowing respectively in the first and second electrical lines with the respective impedance ratios of said at least two flaps.

2. The system according to claim 1 , wherein the solar cells of each flap are organized into strings arranged in parallel, each string comprising a predetermined number of solar cells arranged in series, a position of a solar cell within a string is denoted as a rank of the solar cell; and further comprising a component for determining the rank of a solar cell exhibiting an insulation flaw based on the evaluations of the currents flowing in the first electrical line and the second electrical line, respectively.

3. The system according to claim 1 , wherein the first load and the second load of said each flap are loads of the system for protecting against electrostatic discharges; and wherein the first electrical line and the second electrical line are grounding lines.

4. The System according to claim 1 , further comprising a low-pass filter for low-pass filtering the evaluations of the currents flowing in the first electrical line and the second electrical line, respectively.

5. The system according to claim 1 , wherein the respective impedance ratios of the flaps of the solar generator are all different.

6. The system according to claim 1 , wherein all the flaps of the solar generator are connected to the same first electrical line and to the same second electrical line.

7. A method for detecting and locating an insulation flaw in a solar generator on a spacecraft, comprising the steps of:
evaluating currents flowing in a first electrical line and a second electrical line, respectively, of the solar generator, the solar generator comprises a plurality of flaps, each flap bearing at least one solar cell and being connected to the first electrical line by the first load and to a second electrical line by a second load, said at least one solar cell is connected to an electrical distribution network and said at least one solar cell is electrically insulated from said each flap such that the current flows in the first and second electrical lines in response to an insulation flaw;
detecting the insulation flaw in the solar generator based on evaluations of the currents flowing in at least one of the first electrical line and the second electrical line;
wherein a ratio of impedances of the first load and of the second load of a flap is denoted as an impedance ratio of the flap;
wherein the solar generator comprises at least two flaps exhibiting different respective impedance ratios; and
locating the detected insulation flaw in the solar generator by comparing the evaluations of the currents flowing respectively in the first and second electrical lines with the respective impedance rations of said at least two flaps.

8. The method according to claim 7 , further comprising the step of calculating a ratio of the currents flowing in the first electrical line and the second electrical line.

9. The method according claim 7 , wherein the solar cells of each flap are organized into strings arranged in parallel, each string comprising a predetermined number of solar cells arranged in series, a position of a solar cell within a string is denoted as a rank of the solar cell; and further comprising the steps of:
determining an unitary contribution by each solar cell to the evaluation of the current flowing in the first electrical line or in the second electrical line; and
determining the rank of a solar cell exhibiting an insulation flaw based on the unitary contribution and the evaluation of the current flowing in the first electrical line or in the second electrical line.

10. The method according to claim 7 , further comprising the step of detecting the insulation flaw in the solar generator when the evaluation of the current flowing in the first electrical line or in the second electrical line is higher than a predefined threshold value.

11. A non-transitory computer readable medium comprising a set of program code instructions to be executed by a processor to detect and locate an insulation flaw in a solar generator on a spacecraft, the code programs the processor to be configured to:
evaluate currents flowing in a first electrical line and a second electrical line, respectively, of the solar generator, the solar generator comprises a plurality of flaps, each flap bearing at least one solar cell and being connected to the first electrical line by the first load and to a second electrical line by a second load, said at least one solar cell is connected to an electrical distribution network and said at least one solar cell is electrically insulated from said each flap such that the current flows in the first and second electrical lines in response to an insulation flaw;
detect the insulation flaw in the solar generator based on evaluations of the currents flowing in at least one of the first electrical line and the second electrical line;
wherein a ratio of impedances of the first load and of the second load of a flap is denoted as an impedance ratio of the flap;
wherein the solar generator comprises at least two flaps exhibiting different respective impedance ratios; and
locate the detected insulation flaw in the solar generator by comparing the evaluations of the currents flowing respectively in the first and second electrical lines with the respective impedance rations of said at least two flaps.

Assignees

• Astrium Sas
• Centre Nat D'Etudes Spatiales Cnes
• Airbus Defence & Space Sas

Inventors

• Carla Emmanuelle
• Barde Henri

Classifications

• G01R31/08

  Locating faults in cables, transmission lines, or networks · CPC title

• G01R31/12 Primary

  Testing dielectric strength or breakdown voltage {; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing (G01R31/08, G01R31/327 and G01R31/72 take precedence; measuring in plasmas G01R19/0061; measuring dielectric constants G01R27/2617; ESD, EMC or EMP testing of circuits G01R31/002)} · CPC title

• H02S50/10 Primary

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

• Y02E10/50

  Photovoltaic [PV] energy · CPC title