Method for estimating irradiation attenuation coefficient of flexible solar cell
By establishing a radiation dose calculation model for flexible solar cells and conducting ground-based equivalent tests, the radiation attenuation coefficient of flexible solar cell arrays can be accurately predicted, solving the problem of unreasonable design margins in existing technologies and improving the reliability and design rationality of spacecraft energy systems.
Patent Information
- Application Number
- CN202511886142.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-15
- Publication Date
- 2026-04-21
AI Technical Summary
The lack of a systematic and accurate method for predicting the irradiance attenuation coefficient of flexible solar cell arrays in current technologies leads to unreasonable design margins, affecting the reliability and lightweight design of spacecraft energy systems.
By analyzing spacecraft orbit and space environment parameters, an irradiance dose calculation model for flexible solar cells was established. Combined with ground-based equivalent tests and historical data, the irradiance attenuation coefficient of the solar cells was determined. This process included analyzing orbital parameters, calculating irradiance dose, conducting ground tests, and correcting data to ensure the authenticity and reliability of the data.
It improves the accuracy of radiation dose prediction, ensures the rationality of solar array design and the reliability of on-orbit energy management, and enhances the reliability of spacecraft energy systems.
Smart Images
Figure CN121901676A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of spacecraft solar cell array technology, and in particular relates to a method for estimating the irradiance attenuation coefficient of flexible solar cells. Background Technology
[0002] With the rapid development of spacecraft technology, the demand for lightweight solar arrays is increasing. Flexible solar arrays, due to their light weight and foldability, are widely used in various space missions. As the main energy source for spacecraft, solar arrays are responsible for converting solar energy into electrical energy, ensuring the normal operation of the spacecraft throughout its entire lifespan.
[0003] However, solar arrays are exposed to space radiation for extended periods, and the electrical performance gradually degrades due to high-energy particle irradiation. Compared to traditional rigid solar arrays, flexible solar arrays, with their simplified shielding structure, have relatively weaker radiation protection capabilities, resulting in more significant electrical performance degradation.
[0004] Therefore, accurately predicting the on-orbit irradiance attenuation coefficient of flexible solar arrays has become a key issue in solar array design. Currently, there is a lack of systematic, accurate, and applicable methods for predicting irradiance attenuation in flexible structures, which can easily lead to unreasonable design margins (too large or too small), affecting the reliability and lightweight design of spacecraft energy systems. Summary of the Invention
[0005] This application provides a method for estimating the irradiation attenuation coefficient of flexible solar cells, aiming to solve the problem that it is difficult to accurately predict the electrical performance attenuation coefficient of flexible solar cell arrays under space radiation environment.
[0006] To solve at least one of the above-mentioned technical problems, the technical solution adopted in this application is:
[0007] A method for estimating the irradiance attenuation coefficient of flexible solar cells, comprising the following steps:
[0008] Orbital parameters are analyzed to obtain spacecraft orbital parameters and space environment parameters;
[0009] Based on the orbital parameters and space environment parameters, an irradiation dose calculation model for flexible solar cells is established.
[0010] Ground-based equivalent tests were conducted based on the radiation dose calculated using the aforementioned radiation dose calculation model.
[0011] By combining experimental data and historical data, the irradiance attenuation coefficient of solar cells was determined.
[0012] Furthermore, the track parameters include at least one of track height, inclination angle, and eccentricity.
[0013] Furthermore, the space environment parameters include at least one of solar proton flux, electron flux, and galactic cosmic ray flux.
[0014] Furthermore, the orbital parameter analysis also includes:
[0015] Analyze orbit types and the characteristics of the space radiation environment in orbits to determine the sources of radiation particles;
[0016] The radiation parameters under the worst operating conditions were obtained using a quasi-static model.
[0017] Furthermore, the worst-case radiation parameters include determining the solar energy proton flux and peak flux; and determining the equivalent electron flux under different shielding thicknesses.
[0018] Furthermore, the step of establishing the radiation dose calculation model for flexible solar cells includes:
[0019] Establish a simulation calculation model for the irradiance dose of a solar cell array;
[0020] By equating the surface density of the shielding material to the thickness of the glass cover, the irradiance doses on the front and back sides of the solar cell are calculated separately, and the sum of the two is taken as the total irradiance dose of the solar cell.
[0021] Furthermore, based on the obtained total solar cell irradiance dose, a ground-based equivalent test was conducted, and combined with historical data, the target decay coefficient of the solar cell array at different orbits and at different times was obtained.
[0022] Furthermore, the orbit includes at least one of LEO, GEO, and MEO.
[0023] Furthermore, the attenuation coefficient includes the solar cell voltage attenuation coefficient and the current attenuation coefficient.
[0024] Furthermore, the step of determining the irradiance attenuation coefficient of the solar cell includes:
[0025] By combining historical data, experimental data, and factors such as attitude and orbital changes during the spacecraft's on-orbit operation, the initial attenuation coefficient is corrected to obtain the target attenuation coefficient;
[0026] After the target attenuation coefficient is determined, a design margin of not less than 0.5% is added to it to obtain the final attenuation coefficient.
[0027] This application presents a method for estimating the irradiance attenuation coefficient of flexible solar cells. By analyzing orbital and environmental parameters, an irradiance dose calculation model suitable for flexible solar cells is constructed, improving the accuracy of irradiance dose prediction. Furthermore, a calculation method that superimposes the irradiance doses from both the front and back sides is proposed, better reflecting the actual irradiation conditions of flexible structures. Ground-based experiments corresponding to the predicted doses at a 1:1 ratio are conducted to ensure the data's authenticity and reliability. Combining experimental and historical data, the on-orbit performance attenuation coefficient of the solar cell array can be accurately obtained, while retaining a reasonable margin. This provides a scientific basis for solar cell array design and on-orbit energy management, effectively improving the reliability and design rationality of spacecraft energy systems. Attached Figure Description
[0028] Figure 1 This is a flowchart of a method for estimating the irradiance attenuation coefficient of a flexible solar cell according to this application;
[0029] Figure 2 This is a flowchart of step S1 in this application;
[0030] Figure 3 This is a flowchart of step S2 in this application;
[0031] Figure 4 This is a flowchart of step S3 in this application;
[0032] Figure 5 This is a flowchart of step S4 in this application. Detailed Implementation
[0033] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0034] This embodiment proposes a method for estimating the irradiance attenuation coefficient of flexible solar cells, such as... Figure 1 As shown, the steps include:
[0035] S1. Track parameter analysis: Obtain spacecraft orbit parameters and space environment parameters.
[0036] The goal of analyzing the spacecraft's orbital parameters is to establish accurate input conditions for subsequent radiation dose calculations. The analysis steps are as follows: Figure 2 As shown, the specific content includes:
[0037] S11. Obtain spacecraft orbital parameters.
[0038] Collect and determine the key parameters of the specific orbits that the spacecraft is planning to operate or is currently operating in, including at least one of orbital altitude, inclination, and eccentricity.
[0039] Among them, orbital altitude is the average distance from the Earth's surface (such as 500 km for LEO or 36,000 km for GEO), which directly affects the intensity and duration of crossing the Earth's radiation belts (Van Allen belts).
[0040] Orbital inclination is the angle between the orbital plane and the Earth's equatorial plane, which affects how spacecraft pass through the polar regions (areas where auroral particles fall) and the geomagnetic equator (the region with the strongest radiation).
[0041] Orbital eccentricity describes whether an orbit is nearly circular or elliptical.
[0042] Based on the above key parameters, the geographical location and spatial trajectory of radiation exposure during spacecraft orbital operation can be determined, providing a geometric framework for subsequent analysis of the type and intensity of the radiation environment.
[0043] S12. Obtain space environment parameters.
[0044] The purpose of this step is to collect various space environment parameters present in the orbit that could potentially damage the solar cells. These environmental parameters are used to quantify the type and intensity of radiation sources, serving as input data for calculating radiation dose. These space environment parameters include at least one of the following: solar proton flux, electron flux, and galactic cosmic ray flux.
[0045] S13. Analyze the characteristics of orbit type and space radiation environment.
[0046] Based on spacecraft orbital parameters and space environment parameters, a qualitative-quantitative combined analysis of the orbit is conducted to analyze the orbital type and the characteristics of the space radiation environment, and to determine the source of radiation particles.
[0047] The orbital types include at least one of LEO, GEO, and MEO. LEO is a low Earth orbit, which is affected by protons captured by the South Atlantic Anomaly; GEO is a geosynchronous orbit, which is affected by high-energy electrons and solar protons; and MEO is a medium Earth orbit, which passes through the core of the radiation belts and has the most severe environment.
[0048] Based on the orbit type and quantitatively combined with the characteristics of the space environment, it is possible to analyze which particle is the main source of damage on that specific orbit, as well as the time-varying pattern of the radiation environment, providing a clear physical direction for subsequent modeling.
[0049] S14. Use a quasi-static model to obtain radiation parameters under the worst operating conditions.
[0050] The purpose of obtaining radiation parameters under the worst operating conditions is to provide design inputs with engineering safety margins, ensuring that the solar array designed accordingly can meet power requirements even in extremely harsh environments, thus guaranteeing the reliability of the mission.
[0051] Quasi-static models typically refer to physical / empirical models that describe the average or extreme states of the space environment through long-term observation and verification, such as the AP-8 / AE-8 model, or more modern IGRF geomagnetic models combined with radiation belt models. These models need to consider the influence of solar activity and geomagnetic storms to obtain radiation parameters under the worst conditions.
[0052] The worst-case scenario involves considering the most extreme space weather events (such as strong solar proton events during the peak of solar activity) and the most unfavorable orbital phase that may be encountered during the mission's lifespan, and calculating the maximum expected particle flux / flux, which means determining the solar energy proton flux and peak flux, as well as the equivalent electron flux under different shielding thicknesses.
[0053] S2. Based on the orbital parameters and space environment parameters, establish a radiation dose calculation model for flexible solar cells.
[0054] To address the characteristics of flexible solar arrays—their thin and lightweight structure and shielding properties differing from rigid arrays—a simulation model for calculating the irradiance dose of the solar array was established. By equating the surface density of the shielding material to the thickness of the glass cover, the irradiance doses on the front and back sides of the solar cells were calculated separately, and the sum of these two doses was taken as the total irradiance dose of the solar cell. Figure 3 As shown, the specific content is as follows:
[0055] S21. Establish a simulation calculation model for the irradiance dose of the solar cell array.
[0056] Using the worst-case particle flux obtained in step S14 as input parameters, a simulation model for calculating particle transport and energy deposition in matter is constructed, including particle transport algorithms and solar cell array geometric modeling. The aim is to provide a physical calculation platform that connects macroscopic environmental parameters with microscopic damage effects, from the space particle environment to the absorbed dose inside the cell.
[0057] S22. Analysis and equivalent conversion of shielding thickness.
[0058] First, analyze the thickness of the front and back shielding materials, which involves measuring or obtaining the areal density (in g / cm²) of the front cover layer and the back support structure of the flexible battery. Divide the areal density by the density of standard aerospace radiation-resistant glass to obtain the equivalent glass cover thickness. For example, a layer of polyimide film with 25 mg / cm² is equivalent to approximately 0.09 mm of glass.
[0059] Since the shielding capabilities of flexible materials cannot be directly compared with those of traditional rigid glass covers, this embodiment uses a unified conversion to equivalent glass thickness as a standard for measuring shielding effectiveness. This allows subsequent calculations to be performed using mature radiation attenuation data or empirical formulas based on glass cover thickness, greatly improving the practicality and accuracy of the model.
[0060] S23. Calculate the electron flux irradiated on the front and back sides.
[0061] Using the model of S21 and the equivalent thickness of S22, the following calculations are performed respectively:
[0062] Front-incident electron flux attenuation: simulates the remaining flux of space electrons after passing through the equivalent front glass thickness and subsequent encapsulation materials and reaching the solar cell sensitive layer.
[0063] Back-side incident electron flux attenuation: Simulates the remaining flux of space electrons from the back side, after passing through the equivalent back-side glass thickness (i.e., the supporting structure such as the backplate) and the battery substrate material, to reach the battery sensitive layer.
[0064] Compared to traditional rigid arrays that only focus on the front, this independent quantification method for dual-path radiation attacks accurately quantifies the radiation contribution from the back that was previously underestimated or ignored. This represents a deeper understanding of the damage mechanism of flexible battery arrays.
[0065] S24. Calculate the total irradiated electron flux and dose of the solar cell.
[0066] The remaining electron fluxes reaching the battery sensitive layer from both the front and back directions, calculated in S23, are added together to obtain the total effective flux acting on the battery active region. Then, the cumulative total irradiation dose is obtained based on the mission lifetime integration.
[0067] The total irradiation dose incorporates the effects of all radiation paths, accurately reflecting the overall radiation stress level experienced by flexible solar cells in the space environment, and providing a unique and precise input for the next 1:1 ground test.
[0068] The irradiation dose simulation model is designed to calculate radiation dose based on the characteristics of the double-sided thin-shielded structure of flexible solar arrays. Through the key technology of equivalent thickness conversion, the complex non-standard shielding materials are unified into a standard measurement system. By employing independent dual-path calculations and superposition, a comprehensive image of radiation penetration from both the front and back sides is realistically reconstructed. The model ultimately outputs a high-confidence total radiation dose value that matches the actual irradiation conditions of the flexible structure, providing crucial scientific evidence for subsequent precise ground-based verification experiments and the determination of the attenuation coefficient.
[0069] S3. Conduct a ground-based equivalent test based on the radiation dose calculated by the radiation dose calculation model.
[0070] The purpose of this step is to reproduce the space radiation damage effect under controlled conditions, directly verify the accuracy of the computational model, and obtain real performance degradation data. For example... Figure 4 As shown, the specific content is as follows:
[0071] S31, Ground test parameter mapping.
[0072] Based on the total solar cell irradiation dose and particle energy spectrum information calculated by S2, these are converted into executable parameters for ground-based accelerator experiments. This ensures that the damage mechanism of the ground-based experiments is equivalent to that of the space environment, laying the foundation for the effectiveness of the experiments.
[0073] S32, Ground equivalent irradiation test.
[0074] Using the same flexible solar cells as those used in spacecraft, the open-circuit voltage (Voc), short-circuit current (Isc), maximum power (Pmax), and complete IV curve of the samples were precisely measured under standard test conditions to establish a raw data archive. Experiments were conducted under specified ground-based accelerator irradiation conditions to physically reproduce space radiation damage and directly measure the quantitative relationship between dose and performance degradation.
[0075] S33. Determine the initial attenuation coefficient based on ground tests.
[0076] Based on the test data obtained from S32, the initial attenuation coefficients corresponding to this experiment were calculated. These attenuation coefficients include the solar cell voltage attenuation coefficient and the current attenuation coefficient. The voltage attenuation coefficient is typically expressed as the relative attenuation rate of open-circuit voltage per unit radiation dose (per rad(Si)) (% / rad). Similarly, the current attenuation coefficient is calculated as the relative attenuation rate of short-circuit current per unit dose.
[0077] Universal damage sensitivity parameters were extracted from a single test. These coefficients characterize the inherent response characteristics of this specific type of flexible solar cell to radiation and serve as seed data for on-orbit prediction.
[0078] Throughout the entire experimental verification process, the ground-based equivalent test was conducted in accordance with the national standard "Test Method for Electron Irradiation of Solar Cells for Aerospace Use" (GB / T38190-2019).
[0079] S4. Combining experimental data and historical data, determine the irradiance attenuation coefficient of the solar cell.
[0080] Based on a comprehensive analysis and correction of the initial attenuation coefficient obtained from ground-based equivalent tests and historical on-orbit data, the target attenuation coefficients for the solar array in different orbits and at different times were obtained, and the attenuation coefficients used for the design were finally determined. Figure 5 As shown, the specific steps are as follows:
[0081] S41. Correct the initial attenuation coefficient by combining historical data to obtain the target attenuation coefficient.
[0082] The preliminary attenuation coefficient obtained from the ground equivalent test in step S33 is used as the base coefficient. Combined with historical data, test data, and attitude and orbital changes during the spacecraft's on-orbit operation, and with reference to the actual on-orbit performance degradation data of similar batteries in different satellites (such as multiple GEO orbit satellites), different orbits (such as multiple GEO orbits), and different mission durations (such as high / low solar activity years), calibration and correction are performed to obtain the target attenuation coefficient.
[0083] First, compare the experimental coefficient with the historical data trend. If the historical data shows that the actual decay is more severe, analyze the reasons and adjust the coefficient upward. If the historical data is good, only minor adjustments or maintenance are needed.
[0084] Then, empirical rules are established to quantify the impact of spacecraft attitude changes (such as changes in the solar panel illumination angle caused by sun orientation mode) and orbital perturbations / maintenance (causing small changes in altitude, thus changing the radiation environment) on the cumulative dose, and this impact is converted into the initial attenuation coefficient to finally obtain the target attenuation coefficient.
[0085] S42. Based on the target attenuation coefficient, add a design margin to obtain the final attenuation coefficient.
[0086] After obtaining the target attenuation coefficient after the above correction, a systematic assessment is conducted of all uncertainties in the entire prediction that could cause the performance to be worse than expected.
[0087] Based on industry engineering experience, an additional design margin of no less than 0.5% should be added to the estimated target attenuation rate. For example, if the calculated current attenuation rate is 10.0%, the final design value may be 10.5% or higher. This margin serves as a second layer of protection on top of the already conservatively estimated coefficient.
[0088] In this step, the accuracy and relevance of the target attenuation coefficient are first ensured through correction, moving it from ideal laboratory conditions to align with historical data and the realities of the specific mission. Then, by adding a margin, the reliability and robustness of the final attenuation coefficient are ensured, providing a buffer for all known and unknown risks. The final output attenuation coefficient is no longer a simple physical prediction, but a comprehensive design benchmark that integrates experimental data, historical experience, and mission characteristics; it is the cornerstone for ensuring the lifelong safe and reliable operation of the spacecraft's energy system.
[0089] This application presents a method for estimating the irradiance attenuation coefficient of flexible solar cells. By analyzing orbital and environmental parameters, an irradiance dose calculation model suitable for flexible solar cells is constructed, improving the accuracy of irradiance dose prediction. Furthermore, a calculation method that superimposes the irradiance doses from both the front and back sides is proposed, better reflecting the actual irradiation conditions of flexible structures. Ground-based experiments corresponding to the predicted doses at a 1:1 ratio are conducted to ensure the data's authenticity and reliability. Combining experimental and historical data, the on-orbit performance attenuation coefficient of the solar cell array can be accurately obtained, while retaining a reasonable margin. This provides a scientific basis for solar cell array design and on-orbit energy management, effectively improving the reliability and design rationality of spacecraft energy systems.
[0090] The embodiments of this application have been described in detail above. These descriptions are merely preferred embodiments and should not be construed as limiting the scope of this application. All equivalent variations and modifications made within the scope of this application should still fall within the patent coverage of this application.
Claims
1. A method for estimating the irradiance attenuation coefficient of a flexible solar cell, characterized by the following steps: include: Orbital parameters are analyzed to obtain spacecraft orbital parameters and space environment parameters; Based on the orbital parameters and space environment parameters, an irradiation dose calculation model for flexible solar cells is established. Ground-based equivalent tests were conducted based on the radiation dose calculated using the aforementioned radiation dose calculation model. By combining experimental data and historical data, the irradiance attenuation coefficient of solar cells was determined.
2. The method for estimating the irradiance attenuation coefficient of a flexible solar cell according to claim 1, characterized in that, The track parameters include at least one of track height, inclination angle, and eccentricity.
3. The method for estimating the irradiance attenuation coefficient of a flexible solar cell according to claim 1 or 2, characterized in that, The space environment parameters include at least one of the following: solar proton flux, electron flux, and galactic cosmic ray flux.
4. The method for estimating the irradiance attenuation coefficient of a flexible solar cell according to claim 3, characterized in that, The orbital parameter analysis also includes: Analyze orbit types and the characteristics of the space radiation environment in orbits to determine the sources of radiation particles; The radiation parameters under the worst operating conditions were obtained using a quasi-static model.
5. The method for estimating the irradiance attenuation coefficient of a flexible solar cell according to claim 4, characterized in that, The worst-case radiation parameters include determining the solar energy proton flux and peak flux; and determining the equivalent electron flux under different shielding thicknesses.
6. A method for estimating the irradiance attenuation coefficient of a flexible solar cell according to any one of claims 1-2 and 4-5, characterized in that, The steps for establishing the radiation dose calculation model for flexible solar cells include: Establish a simulation calculation model for the irradiance dose of a solar cell array; By equating the surface density of the shielding material to the thickness of the glass cover, the irradiance doses on the front and back sides of the solar cell are calculated separately, and the sum of the two is taken as the total irradiance dose of the solar cell.
7. The method for estimating the irradiance attenuation coefficient of a flexible solar cell according to claim 6, characterized in that, Ground-based equivalent tests were conducted based on the total solar cell irradiance obtained, and historical data was combined to obtain the target decay coefficient of the solar cell array in different orbits and at different times.
8. The method for estimating the irradiance attenuation coefficient of a flexible solar cell according to claim 7, characterized in that, The orbit includes at least one of LEO, GEO, and MEO.
9. The method for estimating the irradiance attenuation coefficient of a flexible solar cell according to claim 7, characterized in that, The attenuation coefficient includes the solar cell voltage attenuation coefficient and the current attenuation coefficient.
10. A method for estimating the irradiance attenuation coefficient of a flexible solar cell according to any one of claims 7-9, characterized in that, The step of determining the irradiance attenuation coefficient of a solar cell includes: By combining historical data, experimental data, and factors such as attitude and orbital changes during the spacecraft's on-orbit operation, the initial attenuation coefficient is corrected to obtain the target attenuation coefficient; After the target attenuation coefficient is determined, a design margin of not less than 0.5% is added to it to obtain the final attenuation coefficient.