Method and system for monitoring the status and integrity of on-orbit solar cells

Abstract

The embodiment of the present application discloses a kind of in-orbit solar cell piece state and integrity monitoring method and system;Belong to satellite in-orbit detection technical field;The system includes: solar panel by multiple solar cell pieces, power controller and field of view can cover entire solar panel shooting device and processing equipment;Among them, the power controller is configured to: provide input direct current to the solar panel in the solar cell piece to be measured to make the solar cell piece to be measured produce electroluminescence EL phenomenon;The shooting device is configured to: collect the EL image of the solar cell piece to be measured;The processing device is configured to: according to the EL image and the set defect module are matched, obtain the defect formed on the solar cell piece to be measured.This system can improve the in-orbit monitoring precision of solar cell piece state and integrity, and different types of subtle damage formed on solar cell piece surface can be detected.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of satellite in-orbit detection, and particularly relate to a method and system for monitoring the state and integrity of in-orbit solar cell pieces. BACKGROUND

[0002] The spacecraft power system is an important component of the spacecraft, responsible for providing energy for the spacecraft. At present, most spacecraft power systems use solar panels composed of solar cell pieces as satellite power generation equipment to provide solar-to-electric conversion for the satellite during on-orbit operation. Compared with other devices of the spacecraft power system, such as the battery, the power controller, etc., the solar panel, as an external device, is directly exposed to the space environment and needs to withstand the influence of harsh environments such as high-low temperature alternation, particle radiation, ultraviolet radiation, atomic oxygen radiation, and space debris. Moreover, it also faces the threat of space debris and space junk. Therefore, to ensure the normal operation of the satellite in orbit and prolong the on-orbit life of the satellite, it is necessary to monitor the working state and integrity of the satellite solar panel in orbit.

[0003] At present, there is a lack of means for monitoring and fault diagnosis of the solar panel in orbit, mainly by monitoring the output current and output voltage telemetry values of the solar panel as the monitoring criterion of the working state. These monitoring means have poor accuracy and cannot detect the cracks in the solar cell pieces and the fine damage caused by the impact of small space debris. SUMMARY

[0004] Therefore, embodiments of the present application aim to provide a method and system for monitoring the state and integrity of in-orbit solar cell pieces, which can improve the in-orbit monitoring accuracy of the state and integrity of the solar cell pieces and can detect different types of fine damage formed on the surface of the solar cell pieces.

[0005] The technical solution of the embodiments of the present application is as follows:

[0006] In a first aspect, the embodiments of the present application provide a monitoring system for the state and integrity of in-orbit solar cell pieces, which comprises a solar panel composed of a plurality of solar cell pieces, a power controller, and a shooting device and a processing device whose field of view can cover the entire solar panel; wherein,

[0007] The power controller is configured to provide an input direct current to the to-be-tested solar cell piece in the solar panel to make the to-be-tested solar cell piece generate an electroluminescence (EL) phenomenon.

[0008] The shooting device is configured to collect an EL image of the to-be-tested solar cell piece.

[0009] The processing device is configured to match the EL image with a set of defect modules to obtain defects formed on the solar cell under test.

[0010] In a second aspect, the embodiments of the present application provide a method for monitoring the status and integrity of a solar cell in orbit, which is applied to the monitoring system for the status and integrity of a solar cell in orbit as described in the first aspect, and the method comprises:

[0011] Providing a direct current input to the solar cell under test in a solar panel to cause the solar cell under test to generate an electroluminescence (EL) phenomenon;

[0012] Collecting an EL image of the solar cell under test;

[0013] Matching the EL image with a set of defect modules to obtain defects formed on the solar cell under test.

[0014] The embodiments of the present application provide a method and system for monitoring the status and integrity of a solar cell in orbit; by controlling the application of voltage to the solar cell in orbit to generate an EL phenomenon, and collecting an EL image, and then analyzing or diagnosing defects of the solar cell based on the EL image, the in-orbit monitoring accuracy of the status and integrity of the solar cell can be improved, and different types of subtle damage formed on the surface of the solar cell can also be detected. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 A structural schematic diagram of a satellite is provided for the embodiments of the present application;

[0016] Figure 2 A schematic diagram of a monitoring system for the status and integrity of a solar cell in orbit is provided for the embodiments of the present application;

[0017] Figure 3 An implementation schematic diagram of a shooting device is provided for the embodiments of the present application;

[0018] Figure 4 A schematic diagram of a power supply controller is provided for the embodiments of the present application;

[0019] Figure 5 A monitoring flowchart for the status and integrity of a solar cell in orbit is provided for the embodiments of the present application;

[0020] Figure 6 A monitoring flowchart for the status and integrity of a solar cell in orbit is provided for the embodiments of the present application. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

[0022] Referring to Figure 1 It shows a schematic of a satellite 1 that can be applicable to the technical solutions of the embodiments of the present application, the satellite 1 includes a satellite body 11 and a solar panel 12 connected with the satellite body 11 and outside the satellite body 11, the solar panel 12 can be exemplarily arranged in a body type or an unfolded type. In some examples, the solar panel 12 is composed of a plurality of solar cell pieces, and the solar cell pieces can be arranged to form a cell piece array. At present, in order to monitor the working state of the solar cell pieces, output current and output voltage are usually used for fault diagnosis, and these schemes have poor accuracy and cannot detect cracks in single solar cell pieces in the solar panel and slight damage caused by micro-space debris impact.

[0023] Therefore, the embodiments of the present application utilize the electroluminescence capability of solar cell piece materials, combine Figure 1 The satellite schematic is shown, a satellite on-orbit solar cell piece state and integrity monitoring system 20 is proposed, referring to Figure 2 The monitoring system 20 includes a solar panel 12 composed of a plurality of solar cell pieces, a power controller 22, a shooting device 23 with a field of view capable of covering the entire solar panel, and a processing device 24; wherein

[0024] The power controller 22 is configured to provide an input direct current to a to-be-tested solar cell piece in the solar panel 12 to make the to-be-tested solar cell piece generate an electroluminescence (EL) phenomenon;

[0025] The shooting device 23 is configured to collect an EL image of the to-be-tested solar cell piece;

[0026] The processing device 24 is configured to match the EL image with a set of defect modules to obtain defects formed on the to-be-tested solar cell piece.

[0027] It should be noted that in some examples, the material of the solar cell piece can be selected as a three-junction gallium arsenide, which can exhibit EL phenomenon under the application of a set voltage, and the surface of the solar cell piece should generally be smooth and flat, so if there are cracks or fine damage formed by micro debris in space on the solar cell piece, the EL intensity of the fine damage of the solar cell piece will be significantly lower than that of other normal undamaged parts, so that dark lines appear in the EL image of the solar cell piece, and by analyzing the characteristics of the dark line part in the image, the type of defect can be identified. Based on the above example, the material of the three-junction gallium arsenide, the light-emitting wavelength of the solar cell piece made of the material includes 660nm, 855nm, 1700nm, in order to enable the acquisition of the shooting device 23, the corresponding light spectrum range is 400 to 1700nm, and in the specific implementation process, a band-pass filter corresponding to 660nm, 855nm, 1700nm respectively can be arranged at the acquisition end (for example, in front of the camera lens) of the shooting device 23, so as to filter other wavelength spectrum ranges in 400 to 1700nm except 660nm, 855nm, 1700nm, to avoid stray light interference. It can be understood that when the solar cell piece is made of other material types, the light spectrum range of the corresponding shooting device 23 is also adjusted to the EL image spectrum range corresponding to the other material types, and the embodiments of the present application do not make redundant description here.

[0028] In some examples, the shooting device 23 can select an infrared camera, a charge-coupled device (CCD) camera, etc., and the number is at least one. It can be understood that when the field of view of a single shooting device 23 is not enough to cover all the solar cell pieces in the solar panel, multiple shooting devices 23 can be arranged so that the combined field of view range covers all the solar cell pieces. In addition, the shooting device 23 can collect according to the instructions on the ground or the actual scene needs (such as when it is found that the power provided by the solar cell piece is low).

[0029] In some examples, as shown in Figure 3 The shooting device 23 can be implemented to be kept in a position extending out of the satellite body and covering the entire solar panel in the field of view.

[0030] Or, when the state and integrity of the solar cell piece to be tested is not needed to be monitored, it is accommodated in the satellite body; when the state and integrity of the solar cell piece to be tested is needed to be monitored, it is extended out of the satellite body and covers the entire solar panel in the field of view.

[0031] In some examples, as shown in Figure 4As shown, the power controller 22 comprises a monitoring enable switch 221, a voltage conversion and current limiting circuit 222, and a plurality of working mode switches 223, each of which corresponds to a solar cell group in the solar panel;

[0032] The monitoring enable switch 221 is configured to be closed when state and integrity monitoring of a solar cell under test is required, so that the power provided by the satellite battery is transmitted to the voltage conversion and current limiting circuit;

[0033] The working mode switch 223 is configured to switch the solar cell group in which the solar cell under test is located to be connected to the voltage conversion and current limiting circuit when the monitoring enable switch is closed.

[0034] The voltage conversion and current limiting circuit 222 is configured to convert the power provided by the satellite battery into an excitation voltage capable of triggering the EL phenomenon of the solar cell under test, and limit the current flowing to the solar cell under test.

[0035] For the above example, specifically, the above components can be implemented by adding corresponding functional components in the current conventional power controller. Based on this, as Figure 4 As shown, the power controller 22 can further comprise a conventional panel input conversion part 41, a battery charge and discharge control part 42, and a voltage conversion and distribution part 43. Continuing to refer to Figure 4 For a solar panel composed of a solar cell array, a column of solar cells in the array can be formed into a solar cell group, so that the solar panel can be monitored and tested as Figure 4The solar cell groups identified in the above-mentioned embodiment are solar cell group-1, solar cell group-2, …, solar cell group-n; each of the solar cell groups corresponds to a working mode switch, which are identified as 223_1, 223_2, …, 223_n respectively. Each of the working mode switches is preferably implemented as a single-pole double-throw switch. One path (path a in the figure, representing the normal power supply mode) is connected to the sail input conversion part 41 through a diode, and is connected to the battery group through another diode via the battery charge and discharge control part 42 for charging, and is connected to other on-board devices in the satellite body via the voltage conversion and power distribution part 43 for power supply. The other path (path b, representing the monitoring mode) is connected to the voltage conversion and current limiting circuit 222. If it is necessary to monitor the state and integrity of some solar cells, the monitoring enable switch 221 can be closed, and the working mode switch corresponding to the solar cell group to be tested is switched to path b, while the working mode switches corresponding to the other solar cell groups are kept connected to path a. In this way, the power provided by the satellite battery group can be converted by the voltage conversion and current limiting circuit 222 into an excitation voltage capable of triggering the EL phenomenon of the solar cell to be tested, and the current flowing to the solar cell to be tested is limited to prevent damage to the solar cell. That is, the power supply controller converts the sail input into a stable voltage to charge the battery and provide output to other devices in the long-term working mode, and disconnects the connection between the sail and the input conversion circuit when the sail state needs to be detected, and converts the battery power into a suitable voltage to provide to the sail.

[0036] The solar cell to be tested generates an EL phenomenon based on the excitation voltage provided by the voltage conversion and current limiting circuit 222, and the imaging device 23 can capture an EL image of the solar cell generating the EL phenomenon, so that the processing device 24 can determine the subtle damage state of the solar cell to be tested according to the dark line pattern in the captured EL image. In some examples, the processing device 24 can be implemented as a separate device, or integrated into the imaging device or the power supply controller. Moreover, the matched defects and the captured EL image can be downloaded to the ground station for subsequent more precise or accurate analysis and processing. The embodiments of the present application do not make any redundant description here.

[0037] For the above-mentioned specific examples, it should be noted that, in order to ensure the safety of the satellite operation, only a part of the solar cell groups in the solar sail can be selected for detection each time instead of all of them, to ensure that the satellite can still generate sufficient power from the solar cells. In addition, in order to improve the accuracy and quality of the detection results, the above-mentioned monitoring process can be performed when the satellite is in the shadow area. In addition, the solar cell groups can be monitored in the order of one group at a time, so as to complete the monitoring of all the solar cell groups.

[0038] Based on the above example, preferably, the monitoring enabling switch 221 is further configured to be turned off to block the transmission of the power provided by the satellite battery to the voltage conversion and current limiting circuit 222 when the state and integrity monitoring of the solar cell to be tested is not required;

[0039] The working mode switch 223 is configured to connect the solar cell group to the satellite's sailboard input conversion unit to convert to the normal working state to convert solar energy into the power required for the satellite to work and charge the battery when the monitoring enabling switch 221 is turned off.

[0040] For the above Figures 2 to 4 The specific working process of the on-orbit solar cell state and integrity monitoring system 20 shown in the figure can include: Figure 5 As shown in the figure, it can include:

[0041] S501: Start monitoring, close the monitoring enabling switch 221;

[0042] S502: Determine the solar cell group to be tested;

[0043] S503: Switch the working mode switch 223 corresponding to the solar cell group to be tested to connect to the voltage conversion and current limiting circuit 222;

[0044] It should be noted that after S503 is executed, the power provided by the satellite battery can be converted into an excitation voltage capable of triggering the EL phenomenon of the solar cell to be tested via the voltage conversion and current limiting circuit 222, and the current is limited to ensure that the solar cell will not be damaged due to excessive current.

[0045] S504: Extend the shooting device 23 out of the star to collect the EL image of the solar cell group to be tested;

[0046] S505: The processing device 24 diagnoses the defects on the solar cell group to be tested according to the EL image;

[0047] S506: After the diagnosis is completed, switch the working mode switch 223 corresponding to the solar cell group to be tested to the normal power supply mode;

[0048] S507: Determine whether there are other solar cell groups to be tested:

[0049] If yes, go to S503 to monitor and diagnose other solar cell groups to be tested;

[0050] Otherwise, execute S508: Turn off the monitoring enabling switch 221 to make all solar cell groups return to the normal power supply mode, and the monitoring process is ended.

[0051] Figure 5 The complete monitoring process is shown, by controlling the application of voltage to the solar cell to generate EL phenomenon in the on-orbit state, and collecting EL images, and then analyzing or diagnosing defects of the solar cell based on the EL images, not only the on-orbit monitoring accuracy of the state and integrity of the solar cell can be improved, but also different types of subtle damage formed on the surface of the solar cell can be detected.

[0052] Based on the same inventive concept of the foregoing technical solutions, see Figure 6 which shows a monitoring method for the state and integrity of the on-orbit solar cell provided by the embodiment of the application, the monitoring method is applied to the monitoring system 20 for the state and integrity of the on-orbit solar cell in the foregoing technical solutions, and the monitoring method comprises:

[0053] S601: providing an input direct current to the to-be-tested solar cell in the solar panel to make the to-be-tested solar cell generate electroluminescence (EL) phenomenon;

[0054] S602: collecting an EL image of the to-be-tested solar cell;

[0055] S603: matching according to the EL image and a set defect module to obtain defects formed on the to-be-tested solar cell.

[0056] In some examples, the providing of the input direct current to the to-be-tested solar cell in the solar panel to make the to-be-tested solar cell generate EL phenomenon comprises:

[0057] When the state and integrity of the to-be-tested solar cell needs to be monitored, the monitoring enable switch is closed to make the electrical energy provided by the satellite battery pack transmitted to the voltage conversion and current limiting circuit;

[0058] According to the closing of the monitoring enable switch, the solar cell group in which the to-be-tested solar cell is located is switched to access the voltage conversion and current limiting circuit through the working mode switch;

[0059] The electrical energy provided by the satellite battery pack is converted into an excitation voltage capable of triggering the to-be-tested solar cell to generate EL phenomenon by the voltage conversion and current limiting circuit, and the current flowing to the to-be-tested solar cell is limited.

[0060] In some examples, the method further comprises:

[0061] When the state and integrity of the to-be-tested solar cell does not need to be monitored, the monitoring enable switch is opened to block the transmission of the electrical energy provided by the satellite battery pack to the voltage conversion and current limiting circuit;

[0062] Corresponding to the monitoring enabling switch being turned off, the solar cell group is connected to the sailboard input conversion unit of the satellite through the working mode switch, so as to be converted into a normal working state to convert solar energy into the power required by the satellite for working and charging the battery group.

[0063] In some examples, the material of the solar cell is a three-junction gallium arsenide, and correspondingly, the photosensitive spectral range of the EL image is 400-1700 nm.

[0064] It can be understood that the exemplary technical solutions of the above-mentioned on-orbit solar cell state and integrity monitoring method belong to the same concept as the technical solutions of the above-mentioned on-orbit solar cell state and integrity monitoring system 20, and therefore, the details of the above-mentioned on-orbit solar cell state and integrity monitoring method which are not described in detail can be referred to the description of the above-mentioned on-orbit solar cell state and integrity monitoring system 20. The present embodiment does not repeat the description.

[0065] It should be noted that the technical solutions described in the embodiments of the present application can be combined arbitrarily without conflict.

[0066] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A system for monitoring the status and integrity of solar cells in orbit, characterized in that, The monitoring system is applied to a satellite body with a satellite battery pack, and comprises a solar panel composed of a plurality of solar cell pieces, a power supply controller, a shooting device capable of covering the entire solar panel in a field of view, and a processing device. The power supply controller is configured to provide input direct current to a to-be-tested solar cell piece in the solar panel to make the to-be-tested solar cell piece generate an electroluminescence (EL) phenomenon. The shooting device is configured to collect an EL image of the to-be-tested solar cell piece. The processing device is configured to match the EL image with a set of defect modules to obtain defects formed on the to-be-tested solar cell piece. The power supply controller comprises a monitoring enable switch, a voltage conversion and current limiting circuit, and a working mode switch, wherein each working mode switch corresponds to a solar cell piece group in the solar panel. The monitoring enable switch is configured to be closed when state and integrity monitoring of a to-be-tested solar cell piece is needed, so that power provided by the satellite battery pack is transmitted to the voltage conversion and current limiting circuit. The working mode switch is configured to switch the solar cell piece group in which the to-be-tested solar cell piece is located to access the voltage conversion and current limiting circuit when the monitoring enable switch is closed. The voltage conversion and current limiting circuit is used to convert the power provided by the satellite battery pack into an excitation voltage capable of triggering the to-be-tested solar cell piece to generate an EL phenomenon, and limit the current flowing to the to-be-tested solar cell piece.

2. The monitoring system of claim 1, wherein, The monitoring enable switch is also configured to be opened when state and integrity monitoring of a to-be-tested solar cell piece is not needed, so as to block the power provided by the satellite battery pack from being transmitted to the voltage conversion and current limiting circuit. The working mode switch is configured to access the panel input conversion unit of the satellite when the monitoring enable switch is opened, so as to be converted to a normal working state to convert solar energy into power required for satellite operation and charging of the battery pack.

3. The monitoring system of claim 1, wherein, The number of shooting devices is at least one, so that the field of view formed by all shooting devices can cover all solar cell pieces in the entire solar panel.

4. The monitoring system of claim 1, wherein, The shooting device is configured to remain extended out of the satellite body and in a position capable of covering the entire solar panel in a field of view. Alternatively, the shooting device is accommodated in the satellite body when state and integrity monitoring of a to-be-tested solar cell piece is not needed, and is extended out of the satellite body and in a position capable of covering the entire solar panel in a field of view when state and integrity monitoring of a to-be-tested solar cell piece is needed.

5. The monitoring system of claim 1, wherein, The material of the solar cell piece is a triple-junction gallium arsenide, and accordingly, the photosensitive spectrum range of the shooting device corresponds to the light emitting spectrum range of the solar cell piece.

6. A method for monitoring the status and integrity of a solar cell on orbit, characterized in that, The monitoring method is applied to the in-orbit solar cell piece state and integrity monitoring system of any one of claims 1 to 5, and the monitoring method comprises: Providing input direct current to a to-be-tested solar cell in a solar panel to make the to-be-tested solar cell generate electroluminescence (EL) phenomenon; Collecting an EL image of the to-be-tested solar cell; Matching the EL image with a preset defect module to obtain defects on the to-be-tested solar cell; The method further comprises: When the to-be-tested solar cell needs to be monitored, closing a monitoring enable switch to make the power provided by the satellite battery pack transmitted to the voltage conversion and current limiting circuit; According to the closing of the monitoring enable switch, switching the solar cell group where the to-be-tested solar cell is located to access the voltage conversion and current limiting circuit through the working mode switch; The voltage conversion and current limiting circuit converts the power provided by the satellite battery pack into an excitation voltage capable of triggering the to-be-tested solar cell to generate EL phenomenon, and limits the current flowing to the to-be-tested solar cell.

7. The method of claim 6, wherein, The method further comprises: When the to-be-tested solar cell does not need to be monitored, opening the monitoring enable switch to block the power provided by the satellite battery pack from being transmitted to the voltage conversion and current limiting circuit; According to the opening of the monitoring enable switch, connecting the solar cell group to the panel input conversion unit of the satellite through the working mode switch, so as to convert to a normal working state to convert solar energy into power required for the operation of the satellite and the charging of the battery pack.

8. The method of claim 6, wherein, The material of the solar cell is a three-junction gallium arsenide, and correspondingly, the photosensitive spectrum range of the EL image corresponds to the light emitting spectrum range of the solar cell.

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