Thermal matching design method of flexible space solar cell array

Abstract

The invention provides a thermal matching design method for a flexible space solar cell array. The thermal matching design method comprises the following steps: determining a thermal expansion coefficient of a solar cell; the effective thermal expansion coefficient of the flexible substrate in the laying direction of the solar cells is kept in a certain proportion to the thermal expansion coefficient of the solar cells; and determining the thermal mismatch degree of the thermal expansion coefficient and the effective thermal expansion coefficient, and determining the shear modulus and thickness of the adhesive layer according to the thermal mismatch degree under a preset limit temperature difference condition. The method has the beneficial effects that the thermal mismatch driving force is reduced from the source, the thermal stress of the battery piece is reduced, and microcracks or fractures are avoided; parameters of the adhesive layer are matched with the mismatching degree, and vibration load transmission and thermal strain absorption are both considered; and the thermal mismatch degree is quantified, so that the adhesive layer parameter selection has a clear basis, and the design accuracy is improved.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, and in particular relates to a thermal matching design method for flexible space solar cell arrays. Background Technology

[0002] As a core energy supply device for spacecraft, space solar arrays are becoming increasingly important as space technology advances towards higher power, lighter weight, higher storage ratio, and lower cost. Flexible solar arrays, better suited for satellite stacking and efficient space deployment, have become the mainstream technology. However, the coefficients of thermal expansion (CTE) of the materials in each layer of a flexible solar array differ significantly, and temperature fluctuations generate periodic thermal stresses within the structure. These thermal stresses can easily cause microcracks or even fractures in brittle solar cells, leading to decreased photoelectric conversion efficiency, open circuits in the power supply circuit, and directly threatening the spacecraft's on-orbit lifespan.

[0003] Traditional thermal matching designs rely on a "passive decoupling" approach: using low-modulus, high-elasticity silicone rubber as an adhesive, absorbing thermal mismatch strain through shear deformation of the adhesive layer. However, this approach has significant limitations: on the one hand, the adhesive layer is prone to performance degradation in the extreme space environment, and the decoupling effect is greatly reduced after aging; on the other hand, excessively low adhesive layer modulus is not conducive to the transmission and control of vibration loads in the launch segment, making it difficult to balance on-orbit thermal adaptability and launch mechanical stability, resulting in insufficient overall design reliability and limited safety margin.

[0004] Meanwhile, rigid solar arrays in the industry, due to their low folding ratio and high weight, are no longer able to meet the demands of commercial aerospace for "multiple satellites on a single launch" and "high power in a small size," and lack solutions to proactively reduce thermal mismatch at the system level through substrate design. Therefore, a more reliable thermal matching mechanism is urgently needed to improve on-orbit service safety and long-term stability. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a thermal matching design method for flexible space solar cell arrays, which is particularly suitable for reducing the thermal stress of solar cells in space solar cell arrays through thermal matching design.

[0006] The technical solution adopted in this invention is: to provide a thermal matching design method for a flexible space solar cell array, comprising the following steps:

[0007] Determine the thermal expansion coefficient of solar cells ;

[0008] The effective coefficient of thermal expansion of the flexible substrate in the solar cell laying direction satisfy ;

[0009] Determine the degree of thermal mismatch between the coefficient of thermal expansion and the effective coefficient of thermal expansion, and determine the shear modulus of the adhesive layer based on the degree of thermal mismatch under a preset limiting temperature difference condition. and thickness .

[0010] Furthermore, it also includes simulation verification and analysis steps:

[0011] A finite element model is established that includes the flexible substrate, the adhesive layer, and the solar cell.

[0012] Thermal-structural coupling analysis was conducted to verify the strain and stress levels of the solar cells under on-orbit temperature cycling and launch vibration loads.

[0013] Furthermore, the degree of thermal mismatch Through equations Confirmed, when hour, and ;when hour, and ;when hour, and .

[0014] Furthermore, the effective coefficient of thermal expansion can be changed by adjusting the layup of the flexible substrate.

[0015] Furthermore, the layup method includes symmetrical layup.

[0016] Furthermore, the effective coefficient of thermal expansion of the flexible substrate in the solar cell laying direction is 5~6 ppm / ℃.

[0017] Furthermore, the flexible substrate is made of a fiber composite material.

[0018] Furthermore, the solar cells include dual-junction gallium arsenide cells, triple-junction gallium arsenide cells, and monocrystalline silicon cells.

[0019] Furthermore, the coefficient of thermal expansion of the solar cell is 5.5~6.2ppm / ℃.

[0020] Furthermore, the adhesive layer is made of silicone rubber.

[0021] The advantages and positive effects of this invention are as follows: by adopting the above technical solution, the driving force of thermal mismatch is reduced from the source, the thermal stress of the battery cell is reduced, and microcracks or fractures are avoided; the parameters of the adhesive layer are adapted to the degree of mismatch, which takes into account both dynamic load transfer and thermal strain absorption; the degree of thermal mismatch is quantified, so that the selection of adhesive layer parameters has a clear basis and the design accuracy is improved; and the CTE is precisely controlled by adjusting the layup to adapt to the CTE requirements of different types of battery cells. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating a thermal matching design method according to an embodiment of the present invention. Detailed Implementation

[0023] The present disclosure will now be described more fully with reference to the accompanying drawings, which illustrate exemplary embodiments of the present disclosure. The technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present disclosure without creative effort are within the scope of protection of the present disclosure.

[0024] like Figure 1 As shown, the present invention provides a thermal matching design method for a flexible space solar cell array, comprising the following steps:

[0025] S100. Determine the thermal expansion coefficient of the solar cell. ;

[0026] Specifically, select the type of solar cell and use existing technologies (such as thermomechanical analyzers) to accurately measure the coefficient of thermal expansion of the solar cell.

[0027] S200, The effective thermal expansion coefficient of the flexible substrate in the solar cell laying direction is... satisfy ;

[0028] S300. Determine the degree of thermal mismatch between the coefficient of thermal expansion and the effective coefficient of thermal expansion, and determine the shear modulus of the adhesive layer based on the degree of thermal mismatch under preset limiting temperature difference conditions. and thickness .

[0029] By employing the above methods, the driving force of thermal mismatch is reduced from the source, the thermal stress of the solar cells is decreased, and microcracks or fractures are avoided; the parameters of the adhesive layer are adapted to the degree of mismatch, taking into account both dynamic load transfer and thermal strain absorption; and the logic system is designed to adapt to different space conditions, thereby improving the on-orbit reliability of the solar cell array.

[0030] To address the issue that selecting parameters solely through theoretical methods without practical operational verification may lead to a disconnect between design and on-orbit requirements, this embodiment provides an implementation method.

[0031] In one embodiment, a simulation verification and analysis step is also included:

[0032] A finite element model including a flexible substrate, adhesive layer, and solar cell was established;

[0033] Thermal-structural coupling analysis was conducted to verify the strain and stress levels of solar cells under on-orbit temperature cycling and launch vibration loads.

[0034] Specifically, the input parameters and simulation objectives are clearly defined, namely, the key parameters of the flexible substrate, adhesive layer, solar cell, and load parameters, with thermal conditions, vibration conditions, and coupling verification as the simulation objectives. A three-dimensional finite element model is established and meshed. After applying boundary conditions and loads, the solution settings and calculations are performed. The maximum thermal stress of the solar cell, the maximum shear strain of the adhesive layer, and the thermal deformation difference between the flexible substrate and the solar cell are extracted for verification analysis.

[0035] To further verify the strain and stress levels of solar cells and prove the effectiveness of the thermal matching design, test pieces were prepared, and ground-based thermal cycling and mechanical environment tests were conducted to measure the strain and stress levels of the solar cells in the field.

[0036] By using the above methods, the on-orbit temperature cycling and vibration loads can be replicated in advance, accurately predicting the stress and strain levels of the solar cells; avoiding test waste caused by invalid parameters and reducing R&D costs; ensuring that the design scheme meets the adaptability to the space environment and improving the safety of on-orbit service.

[0037] To address the issues of the lack of quantitative standards for thermal mismatch and the ambiguity in selecting adhesive layer parameters, this embodiment provides an implementation method.

[0038] In one embodiment, the degree of thermal mismatch Through equations Confirmed, when It was determined that the degree of thermal mismatch was low. and ;when When determined to be of medium thermal mismatch, and ;when It was determined at that time to be a high degree of thermal mismatch. and .

[0039] By using the above method, the degree of thermal mismatch is quantified, providing a clear basis for the selection of adhesive layer parameters and improving design accuracy; different mismatch scenarios correspond to specific parameter ranges, making them more adaptable; and the parameter debugging cycle is reduced, ensuring the consistency and repeatability of design results.

[0040] To address the issue of only specifying the substrate material without clarifying the CTE control method, this embodiment provides an implementation method.

[0041] In one embodiment, the effective coefficient of thermal expansion is changed by adjusting the layup of the flexible substrate.

[0042] Using the above method, precise control of CTE can be achieved through layer adjustment, adapting to the CTE requirements of different types of solar cells; the design is highly flexible and can be customized for different mission environments; the operability of active matching is enhanced, and the scope of design applicability is broadened.

[0043] In one embodiment, the layup method includes symmetrical layup.

[0044] Specifically, symmetrical layup refers to precisely controlling the effective coefficient of thermal expansion (CTE) of the substrate in the layup direction by adjusting the ratio of 0° layers to 90° layers. The CTE range of the flexible substrate is determined by the CTE of the solar panel. The total number of layup layers is even, with 0° and 90° layers alternating, and the number of layers on both sides of the symmetrical plane is consistent. After layup, the effective coefficient of thermal expansion of the flexible substrate in the solar cell layup direction is predicted using classical laminate theory or a progressive homogenization method based on representative volume units.

[0045] In one embodiment, the effective coefficient of thermal expansion of the flexible substrate in the solar cell laying direction is 5~6 ppm / ℃.

[0046] In one embodiment, the flexible substrate is made of a fiber composite material.

[0047] In one embodiment, the solar cell includes a double-junction gallium arsenide cell, a triple-junction gallium arsenide cell, and a monocrystalline silicon cell.

[0048] In one embodiment, the coefficient of thermal expansion of the solar cell is 5.5~6.2ppm / ℃.

[0049] In one embodiment, the adhesive layer is made of silicone rubber.

[0050] The following description, in conjunction with a preferred embodiment, illustrates the content involved in the above embodiments.

[0051] The solar cells used are triple-junction gallium arsenide cells with a thermal expansion coefficient of 5.8 ppm / ℃. The flexible substrate is made of T700 fiber plain weave prepreg and employs... The symmetrical layup design, predicted and experimentally corrected using classical laminate theory, yields an effective coefficient of thermal expansion of 6.0 ppm / ℃ in the cell layup direction. A dense polymer interface layer is provided between the flexible substrate and the silicone rubber adhesive layer to enhance adhesion. The adhesive layer uses space-grade silicone rubber. and The degree of thermal mismatch is 1.03, therefore the shear modulus of the adhesive layer is selected. ,thickness Subsequently, a finite element model was established for thermo-structural coupling analysis, and finally, experimental specimens were prepared for testing. to Ground thermal cycling tests and mechanical environment tests showed that the maximum thermal stress of the solar cells was far below their ultimate strength, and the strain transfer ratio met the design requirements in the vibration test. The overall system formed a dual guarantee mechanism of "substrate active matching as the main method and adhesive layer passive decoupling as the auxiliary method", which significantly improved the reliability and safety margin.

[0052] Based on embodiments of this disclosure, this disclosure also provides an electronic device, a readable storage medium, and a computer program product.

[0053] An electronic device includes at least one processor and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to execute the thermal matching design method for flexible space solar cell arrays provided in this disclosure.

[0054] Electronic devices are intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0055] A non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to cause a computer to execute the thermal matching design method for flexible space solar cell arrays provided in this disclosure.

[0056] The various embodiments of this disclosure can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0057] A computer program product includes a computer program / instructions, which are executed by a processor to provide a thermal matching design method for flexible space solar cell arrays.

[0058] The program code used to implement the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0059] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0060] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A thermal matching design method for a flexible space solar cell array, characterized in that, Includes the following steps: Determine the thermal expansion coefficient of solar cells ; The effective coefficient of thermal expansion of the flexible substrate in the solar cell laying direction satisfy ; Determine the degree of thermal mismatch between the coefficient of thermal expansion and the effective coefficient of thermal expansion, and determine the shear modulus of the adhesive layer based on the degree of thermal mismatch under a preset limiting temperature difference condition. and thickness .

2. The thermal matching design method for flexible space solar cell arrays according to claim 1, characterized in that, It also includes simulation verification and analysis steps: A finite element model is established that includes the flexible substrate, the adhesive layer, and the solar cell. Thermal-structural coupling analysis was conducted to verify the strain and stress levels of the solar cells under on-orbit temperature cycling and launch vibration loads.

3. The thermal matching design method for flexible space solar cell arrays according to claim 1, characterized in that: The degree of thermal mismatch Through equations Confirmed, when hour, and ;when hour, and ;when hour, and .

4. The thermal matching design method for flexible space solar cell arrays according to any one of claims 1-3, characterized in that: The effective coefficient of thermal expansion is changed by adjusting the layup of the flexible substrate.

5. The thermal matching design method for flexible space solar cell arrays according to claim 4, characterized in that: The layup method includes symmetrical layup.

6. The thermal matching design method for flexible space solar cell arrays according to claim 5, characterized in that: The effective coefficient of thermal expansion of the flexible substrate in the direction of solar cell laying is 5~6 ppm / ℃.

7. The thermal matching design method for flexible space solar cell arrays according to claim 6, characterized in that: The flexible substrate is made of fiber composite material.

8. The thermal matching design method for flexible space solar cell arrays according to claim 1, characterized in that: The solar cells include double-junction gallium arsenide cells, triple-junction gallium arsenide cells, and monocrystalline silicon cells.

9. The thermal matching design method for flexible space solar cell arrays according to claim 8, characterized in that: The coefficient of thermal expansion of the solar cell is 5.5~6.2ppm / ℃.

10. The thermal matching design method for flexible space solar cell arrays according to claim 3, characterized in that: The adhesive layer is made of silicone rubber.

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