A method and system for detecting performance of a solar cell in orbit

Abstract

The application provides a kind of solar cell on-orbit performance detection method and system, it is related to spacecraft power system technical field, for the on-orbit performance detection of photovoltaic module on satellite sailboard, photovoltaic module includes measured solar cell, heater and temperature sensor, and photovoltaic module is connected with whole star bus through voltage regulation module;Method includes: through temperature sensor, the working temperature of measured solar cell is acquired, and according to preset temperature sequence, control heater carries out temperature control to measured solar cell;When working temperature reaches and stabilizes at each target temperature in preset temperature sequence, the on-orbit performance detection of measured solar cell is carried out, and the on-orbit performance detection data of measured solar cell is obtained.The on-orbit performance detection precision of solar cell is improved.

Description

Technical Field

[0001] This invention relates to the field of spacecraft power system technology, and more specifically, to a method and system for on-orbit performance testing of solar cells. Background Technology

[0002] Solar cells, as a promising next-generation technology in the field of space photovoltaics (such as perovskite solar cells), still lack sufficient on-orbit verification data regarding their actual performance and long-term reliability in the space environment. Currently, the evaluation of the performance of solar cells in space applications mainly relies on on-orbit experiments, which involve sending solar cell samples into space with spacecraft and collecting their output voltage and current data under natural conditions.

[0003] In related technologies, on-orbit testing can only record single operating point data at the natural temperature of the solar panel, making it difficult to systematically measure the IV characteristics of the tested battery under various operating conditions. At the same time, due to the limitation of conventional satellite power systems that only collect fixed operating point voltage and current, it is difficult to obtain IV hysteresis effect data that characterizes battery stability, and there is also a lack of long-term periodic monitoring capabilities for the tested battery. Consequently, the on-orbit performance testing of the battery is not effective, making it difficult to meet the needs of space application engineering decisions for on-orbit verification data. Summary of the Invention

[0004] The problem addressed by this invention is how to improve the accuracy of on-orbit performance testing of solar cells.

[0005] To address the above problems, this invention provides a method and system for on-orbit performance testing of solar cells.

[0006] In a first aspect, the present invention provides a method for testing the on-orbit performance of a solar cell, used to test the on-orbit performance of a photovoltaic module on a satellite solar panel, wherein the photovoltaic module includes a solar cell under test, a heater and a temperature sensor, and the photovoltaic module is connected to the satellite bus via a voltage regulation module. The method includes: The temperature sensor is used to obtain the operating temperature of the solar cell under test, and the heater is controlled to control the temperature of the solar cell under test according to a preset temperature sequence. When the operating temperature reaches and stabilizes at each target temperature in the preset temperature sequence, the on-orbit performance of the solar cell under test is tested. Specifically, at each target temperature, the operating voltage of the solar cell under test is adjusted by the voltage regulation module to control the operating point of the solar cell under test to perform forward and reverse scanning; during the forward and reverse scanning process, the voltage and current values ​​corresponding to the operating point are collected, and based on the voltage and current values ​​corresponding to the operating point, the forward IV characteristic data and reverse IV characteristic data of the solar cell under test at each target temperature are obtained. Hysteresis and degradation analyses are performed based on the forward IV characteristic data and reverse IV characteristic data at each target temperature to obtain the on-orbit performance test data of the solar cell under test.

[0007] Optionally, the step of acquiring the operating temperature of the solar cell under test through the temperature sensor and controlling the heater to control the temperature of the solar cell under test according to a preset temperature sequence includes: The current operating temperature of the solar cell under test is obtained through the temperature sensor. Based on the current operating temperature, determine the current target temperature from the target temperatures in the preset temperature sequence; Based on the current operating temperature and the current target temperature, determine the switching duty cycle of the heater; The temperature of the solar cell under test is controlled based on the switching duty cycle of the heater.

[0008] Optionally, determining the switching duty cycle of the heater based on the current operating temperature and the current target temperature includes: When the current operating temperature is lower than the current target temperature, the previous target temperature in the preset temperature sequence that is before the current target temperature is obtained, and the switch duty cycle is determined based on the previous target temperature, the current operating temperature, and the current target temperature. When the current operating temperature reaches the current target temperature, the switch duty cycle is set to 0.

[0009] Optionally, the step of adjusting the operating voltage of the solar cell under test through the voltage adjustment module to control the operating point of the solar cell under test to perform forward and reverse scanning includes: The voltage regulation module increases the operating voltage of the solar cell under test from the voltage value corresponding to the short circuit state to the voltage value corresponding to the open circuit state, and controls the operating point of the solar cell under test to perform a forward scan from the short circuit state to the open circuit state along the voltage increase direction. Furthermore, the voltage regulation module reduces the operating voltage of the solar cell under test from the voltage value corresponding to the open circuit state to the voltage value corresponding to the short circuit state, and controls the operating point of the solar cell under test to perform a reverse scan from the open circuit state to the short circuit state along the voltage decreasing direction.

[0010] Optionally, the voltage regulation module includes a boost circuit, the input of which is connected to the solar cell under test, and the output of which is connected to the satellite bus. The step of adjusting the operating voltage of the solar cell under test through the voltage adjustment module to control the operating point of the solar cell under test to perform forward and reverse scanning includes: The operating voltage of the solar cell under test is adjusted by the output duty cycle of the boost circuit, and the operating point of the solar cell under test is controlled to perform forward and reverse scanning.

[0011] Optionally, adjusting the operating voltage of the tested solar cell by means of the output duty cycle of the boost circuit includes: For forward scanning, by controlling the output duty cycle to gradually increase from a first preset value to a second preset value in a preset step size, the operating voltage of the tested solar cell is increased from the voltage value corresponding to the short circuit state to the voltage value corresponding to the open circuit state. For reverse scanning, by controlling the output duty cycle to gradually decrease from the second preset value to the first preset value with the preset step size, the operating voltage of the tested solar cell is reduced from the voltage value corresponding to the open circuit state to the voltage value corresponding to the short circuit state.

[0012] Optionally, during the forward and reverse scanning process, acquiring the voltage and current values ​​corresponding to the operating point includes: During the forward and reverse scanning process, when the output duty cycle of the boost circuit changes once according to the preset step size and reaches the duty cycle corresponding to the current step, the voltage and current values ​​corresponding to the current operating point of the solar cell under test are obtained.

[0013] Optionally, obtaining the forward IV characteristic data and reverse IV characteristic data of the tested solar cell at each target temperature based on the voltage and current values ​​corresponding to the operating point includes: The voltage and current values ​​corresponding to each operating point collected during the forward scanning process are arranged in ascending order of voltage value to construct the forward IV characteristic data at the target temperature; The voltage and current values ​​corresponding to each operating point collected during the reverse scanning process are arranged in descending order of voltage value to construct the reverse IV characteristic data at the target temperature.

[0014] Optionally, the hysteresis analysis and degradation analysis based on the forward IV characteristic data and reverse IV characteristic data at each target temperature to obtain the on-orbit performance test data of the tested solar cell includes: The corresponding open-circuit voltage, short-circuit current, maximum power point voltage, and maximum power point current are extracted from the forward IV characteristic data and the reverse IV characteristic data at each target temperature, respectively. Based on the open-circuit voltage, short-circuit current, maximum power point voltage, and maximum power point current corresponding to the forward IV characteristic data and the reverse IV characteristic data, the open-circuit voltage difference ratio, short-circuit current difference ratio, maximum power point voltage difference ratio, and maximum power point current difference ratio are determined to obtain the hysteresis effect characterization parameters at each target temperature. After each forward and reverse scan for each target temperature in the preset temperature sequence is completed, the detection count is updated, and the number of orbital runs corresponding to the forward and reverse scans at the target temperature is determined based on the updated detection count. By correlating the forward IV characteristic data and reverse IV characteristic data at each target temperature with the corresponding number of orbital runs, the performance degradation data of the tested solar cell under different number of orbital runs can be obtained. The hysteresis effect characterization parameters and performance degradation data at all target temperatures are used as the on-orbit performance detection data.

[0015] Secondly, the present invention also provides an on-orbit performance testing system for solar cells, used to test the on-orbit performance of photovoltaic modules on satellite solar panels. The photovoltaic module includes the solar cell under test, a heater, and a temperature sensor. The photovoltaic module is connected to the satellite bus via a voltage regulation module. The system includes: A temperature control unit is used to acquire the operating temperature of the solar cell under test through the temperature sensor, and to control the heater to control the temperature of the solar cell under test according to a preset temperature sequence. The on-orbit performance testing unit is used to perform on-orbit performance testing on the solar cell under test when the operating temperature reaches and stabilizes at each target temperature in the preset temperature sequence. Specifically, at each target temperature, the operating voltage of the solar cell under test is adjusted by the voltage regulation module to control the operating point of the solar cell under test to perform forward and reverse scanning; during the forward and reverse scanning process, the voltage and current values ​​corresponding to the operating point are collected, and based on the voltage and current values ​​corresponding to the operating point, the forward IV characteristic data and reverse IV characteristic data of the solar cell under test at each target temperature are obtained. The data analysis unit is used to perform hysteresis analysis and degradation analysis based on the forward IV characteristic data and reverse IV characteristic data at each target temperature to obtain the on-orbit performance test data of the solar cell under test.

[0016] The solar cell on-orbit performance testing method and system of this invention achieves effective electrical isolation between the tested solar cell, heater, and temperature sensor and the satellite's main power system. This ensures that a fault in the tested sample does not endanger the safety of the entire satellite and provides an independent electrical interface and hardware foundation for subsequent active temperature control and voltage scanning, thus ensuring the safety and controllability of the on-orbit testing process. Furthermore, the system uses a temperature sensor to acquire the operating temperature of the tested solar cell in real time and implements active temperature control based on a preset temperature sequence. This allows the tested solar cell to reach a stable state at different target temperatures before testing, thus covering performance data acquisition under multiple temperature conditions within a single on-orbit testing cycle. This avoids the limitation of traditional methods that rely solely on the natural temperature of the solar panels, resulting in a single testing condition. Finally, at each target temperature, the voltage adjustment module actively adjusts the operating voltage to control the operating point for complete forward and reverse scanning, overcoming the limitation of conventional power systems that only collect data at a fixed operating temperature. The limitations of point data allow the detection to cover the complete voltage range from short circuit to open circuit and from open circuit to short circuit, ensuring the integrity of the IV characteristic curve and the accuracy of the acquisition of various characteristic parameters, thus providing reliable data for the comparison of forward and reverse IV curves. Hysteresis analysis based on complete forward and reverse IV characteristic data acquired at each temperature point can quantitatively characterize the battery's unique hysteresis effect through the difference between forward and reverse scanning results. At the same time, the decay analysis of long-term multi-round detection data captures the performance change pattern with the number of orbital runs, avoiding the shortcomings of single operating point monitoring in reflecting the battery's true output capability and stability changes. Finally, the hysteresis effect characterization parameters at each target temperature and long-term decay data are combined as the on-orbit performance detection results, giving the detection data multi-dimensional information including temperature dimension, full IV characteristics, and long-term change trends. Compared with the traditional method of collecting only single operating point data at natural temperature, this significantly improves the comprehensiveness, accuracy, and reliability of solar cell on-orbit performance detection, thereby effectively improving the accuracy of solar cell on-orbit performance detection. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the on-orbit performance testing method for solar cells according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the arrangement structure of a photovoltaic module according to another embodiment of the present invention; Figure 3 This is a typical cross-sectional view of temperature control and forward / reverse scanning according to another embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a solar cell on-orbit performance testing system according to another embodiment of the present invention. Detailed Implementation

[0018] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0019] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0020] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0021] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0022] Combination Figure 1As shown in the figure, the on-orbit performance testing method for solar cells provided in this embodiment of the invention is used to test the on-orbit performance of photovoltaic modules on satellite solar panels. The photovoltaic module includes the solar cell under test, a heater, and a temperature sensor. The photovoltaic module is connected to the satellite bus via a voltage regulation module.

[0023] Specifically, in combination Figure 2 As shown, in this embodiment, the solar cell sample is welded onto the cell substrate. The heater is a polyimide film heater attached to the back of the substrate, and the temperature sensor is an MF51 NTC thermistor. The photovoltaic module is connected to the voltage regulation module via an independent cable, and the voltage regulation module is then connected to the satellite bus via an isolation diode, thereby achieving electrical decoupling between the sample under test and the satellite's main power supply. The isolation diode utilizes its unidirectional conduction characteristic to ensure that current flows only from the photovoltaic module side to the satellite bus side, preventing the current from the satellite bus from flowing back into the solar cell under test. This avoids backflow of bus current interfering with the true output characteristics of the tested cell and causing distortion of the collected voltage and current data. Simultaneously, when the tested solar cell experiences a short circuit, open circuit, or other abnormal fault, the isolation diode can block the path of fault current propagation to the satellite bus, preventing the failure of a single tested sample from affecting the entire satellite's main power system and ensuring the safety and stability of the entire satellite's power system during on-orbit testing.

[0024] The method includes: The operating temperature of the solar cell under test is obtained through the temperature sensor, and the heater is controlled to control the temperature of the solar cell under test according to a preset temperature sequence.

[0025] Specifically, regarding temperature control, the operating temperature of the solar cell under test is obtained through a temperature sensor, and the heater is controlled to regulate the temperature of the solar cell according to a preset temperature sequence. It should be understood that the temperature sensor, mounted on the back of the battery substrate, has advantages such as small size, fast response, and resistance to mechanical vibration, enabling real-time sensing of temperature changes in the battery under test. When the spacecraft moves from the shadow area to the sunlight area, the solar panels heat up under illumination. Active temperature control is introduced during this natural heating process. Specifically, the heating power is adjusted based on the difference between the current operating temperature fed back by the temperature sensor and the target temperature in the preset temperature sequence, thereby accelerating or slowing down the heating rate, allowing the battery under test to sequentially reach and stabilize at multiple preset target temperatures. By introducing an active temperature regulation mechanism, the passive situation of traditional on-orbit experiments relying solely on the natural temperature of the solar panels is overcome, providing a temperature-controllable testing environment. The preset temperature sequence consists of multiple target temperature values ​​arranged sequentially from low to high temperature. For example, in this embodiment, the target temperature values ​​are -60℃, -40℃, -20℃, 0℃, 20℃, 40℃, 60℃, 80℃, 100℃, 120℃, and 140℃. The preset temperature sequence covers the typical temperature range that the solar panels of the space power system may experience during on-orbit operation, including both low and high temperature ranges. This allows for the systematic acquisition of battery output characteristic data under different temperature conditions within a single detection cycle, providing complete temperature dimension information for subsequent analysis of the impact of temperature on hysteresis and output performance.

[0026] When the operating temperature reaches and stabilizes at each target temperature in the preset temperature sequence, the on-orbit performance of the solar cell under test is tested.

[0027] Specifically, when the operating temperature reaches and stabilizes at each target temperature in the preset temperature sequence, the on-orbit performance of the solar cell under test is tested. "Stabilizes at" means that after the heater stops heating, the operating temperature of the tested cell remains constant within the allowable error range of the current target temperature (e.g., ±1℃). At this point, the carrier transport and ion migration behavior inside the cell reaches a relative equilibrium state at that temperature, which is the optimal time to perform IV characteristic measurements. By triggering the test at each target temperature stabilization point, the comparability and repeatability of IV data at different temperatures are ensured in the temperature dimension, avoiding measurement deviations caused by thermal imbalance during temperature transitions.

[0028] Specifically, at each target temperature, the operating voltage of the solar cell under test is adjusted by the voltage regulation module to control the operating point of the solar cell under test to perform forward and reverse scanning; during the forward and reverse scanning process, the voltage and current values ​​corresponding to the operating point are collected, and based on the voltage and current values ​​corresponding to the operating point, the forward IV characteristic data and reverse IV characteristic data of the solar cell under test at each target temperature are obtained.

[0029] Specifically, at each target temperature, the voltage regulation module actively adjusts the operating voltage applied across the battery under test. After the target temperature stabilizes, the module continuously increases the operating voltage from the near-zero short-circuit state to the open-circuit state. During this process, the operating point of the battery under test gradually moves along the IV curve from the short-circuit current point to the open-circuit voltage point. At each voltage value adjusted, voltage and current data of the current operating point are collected, forming a series of voltage-current data pairs. After completing the full-range scan in the voltage increasing direction, the positive IV characteristic data is obtained. Subsequently, the operating voltage is continuously decreased from the open-circuit state to the short-circuit state. The operating point gradually moves along the IV curve in the reverse direction from the open-circuit voltage point to the short-circuit current point. Similarly, voltage and current data of each operating point are collected. After completing the full-range scan in the voltage decreasing direction, the reverse IV characteristic data is obtained. By performing two complete voltage range scans in both the forward and reverse directions, the detection can cover the entire voltage range from short circuit to open circuit and from open circuit to short circuit, ensuring the accurate acquisition of the complete IV characteristic curve and various characteristic parameters (such as open circuit voltage, short circuit current, maximum power point voltage and current, etc.). Furthermore, since this scanning process is performed after each target temperature has stabilized, and the voltage adjustment range and sampling density of the forward and reverse scans remain consistent, the obtained forward and reverse IV characteristic data differ only in the scanning direction. This provides a comparable data basis with the same temperature conditions and the same voltage sampling reference for subsequent comparative analysis of hysteresis effects.

[0030] Hysteresis and degradation analyses are performed based on the forward IV characteristic data and reverse IV characteristic data at each target temperature to obtain the on-orbit performance test data of the solar cell under test.

[0031] Specifically, hysteresis analysis refers to extracting characteristic parameters representing the hysteresis effect of the battery from the forward and reverse IV characteristic data at each temperature point. By calculating the hysteresis characteristic parameters at multiple target temperatures, the variation law of the hysteresis effect with temperature can be obtained, thereby comprehensively evaluating the stability performance of the battery under different temperature conditions. Attenuation analysis refers to comparing the forward and reverse IV characteristic data obtained at each temperature in each round of testing with historical test data after completing all preset temperature sequences. This observes the changing trends of key performance indicators such as open-circuit voltage, short-circuit current, and maximum power point power at the same target temperature with the increase of testing rounds. Since each round of testing is performed under the same preset temperature sequence conditions, the data between each round have the same temperature benchmark and the same voltage scan range, ensuring that performance changes fully reflect the evolution of the battery's own output characteristics rather than differences in test conditions. Through accumulation over multiple rounds, systematic data on the performance degradation of the tested solar cell during continuous on-orbit service can be obtained. Hysteresis analysis reveals the differences in forward and reverse scanning characteristics at various temperature points, reflecting the instantaneous response characteristics of the battery at the current moment due to internal ion migration behavior. Degradation analysis reveals the changing trends of key performance indicators at various temperature points with increasing on-orbit time, reflecting the battery's durability evolution under long-term space environmental conditions. These two analyses jointly characterize the battery's on-orbit behavior from two dimensions: transient hysteresis response and long-term performance degradation. Integrating hysteresis effect parameters at various target temperatures and long-term degradation data as on-orbit performance testing results provides multi-dimensional information encompassing temperature, IV full characteristics, and long-term trends. Compared to traditional methods that only collect data from a single operating point at natural temperature, this significantly improves the comprehensiveness and accuracy of the testing.

[0032] The on-orbit performance testing method for solar cells of this invention achieves effective electrical isolation between the tested solar cell, heater, and temperature sensor and the satellite's main power system. This ensures that a fault in the tested sample does not endanger the safety of the entire satellite and provides an independent electrical interface and hardware foundation for subsequent active temperature control and voltage scanning, thus ensuring the safety and controllability of the on-orbit testing process. Furthermore, the method uses a temperature sensor to acquire the operating temperature of the tested solar cell in real time and implements active temperature control based on a preset temperature sequence. This allows the tested solar cell to reach a stable state at different target temperatures before testing, thus covering performance data acquisition under multiple temperature conditions within a single on-orbit testing cycle. This avoids the limitation of traditional methods that rely solely on the natural temperature of the solar panels, resulting in a single testing condition. Finally, at each target temperature, the voltage adjustment module actively adjusts the operating voltage to control the operating point for complete forward and reverse scanning, breaking through the limitation of conventional power systems that only collect data at a fixed number of operating points. By overcoming the limitations of conventional methods, the detection can cover the complete voltage range from short circuit to open circuit and from open circuit to short circuit, ensuring the integrity of the IV characteristic curve and the accuracy of the acquisition of various characteristic parameters, thus providing reliable data for the comparison of forward and reverse IV curves. Hysteresis analysis based on complete forward and reverse IV characteristic data acquired at various temperature points can quantitatively characterize the battery's unique hysteresis effect through the difference between forward and reverse scanning results. At the same time, by analyzing the decay of long-term, multi-round detection data, the performance variation law with the number of orbital runs is captured, avoiding the shortcomings of single operating point monitoring in reflecting the battery's true output capability and stability changes. Finally, the hysteresis effect characterization parameters at various target temperatures and long-term decay data are combined as the on-orbit performance detection results, giving the detection data multi-dimensional information including temperature dimension, full IV characteristics, and long-term variation trend. Compared with the traditional method of collecting only single operating point data at natural temperature, this significantly improves the comprehensiveness, accuracy, and reliability of solar cell on-orbit performance detection, thereby effectively improving the accuracy of solar cell on-orbit performance detection.

[0033] Optionally, the step of acquiring the operating temperature of the solar cell under test through the temperature sensor and controlling the heater to control the temperature of the solar cell under test according to a preset temperature sequence includes: The current operating temperature of the solar cell under test is obtained through the temperature sensor. Based on the current operating temperature, determine the current target temperature from the target temperatures in the preset temperature sequence; Based on the current operating temperature and the current target temperature, determine the switching duty cycle of the heater; The temperature of the solar cell under test is controlled based on the switching duty cycle of the heater.

[0034] Specifically, the current operating temperature of the solar cell under test is first acquired in real time using a temperature sensor mounted on the back of the solar panel. In a preferred embodiment of the invention, the temperature sensor is an MF51 type NTC thermistor, which has advantages such as small size, fast response, and resistance to mechanical vibration. Its operating temperature range covers -55℃ to +300℃, meeting the wide temperature measurement requirements of approximately -100℃ to +180℃ for the solar panels of the space power system during on-orbit operation. After acquiring the current operating temperature, the target temperature to be reached is determined from the preset temperature sequence based on the comparison between the current operating temperature and the target temperature values ​​in the preset temperature sequence. The preset temperature sequence consists of multiple target temperature values ​​arranged sequentially from low to high temperature. In this embodiment, these values ​​are -60℃, -40℃, -20℃, 0℃, 20℃, 40℃, 60℃, 80℃, 100℃, 120℃, and 140℃, covering the typical temperature range that the solar panels of the space power system may experience during on-orbit operation. Based on this, the heating power of the heater is controlled by controlling the switching duty cycle of the heater. In this embodiment, the heater is a polyimide film heater adhered to the back of the battery substrate. It enables precise temperature regulation and is a widely used active thermal control component in spacecraft thermal control systems, exhibiting excellent high and low temperature resistance, flexibility, and high reliability. The switching duty cycle determines the proportion of time the heater is energized per unit time, thus determining the heating power. When the temperature is below the target value, the duty cycle is larger to accelerate heating; when the temperature approaches the target value, the duty cycle gradually decreases to prevent overshoot. After determining the switching duty cycle, the heater is controlled according to this duty cycle to control the temperature of the solar cell under test. As the spacecraft moves from the shadow area to the illumination area and the solar panel is heated by illumination, the heating power is actively adjusted through the aforementioned closed-loop control logic, enabling the battery under test to sequentially reach and stabilize at each target temperature value in the preset temperature sequence. After each target temperature stabilizes, heating is paused to perform forward and reverse IV scans. After the scan is completed, heating is restarted to continue heating to the next target temperature, and this cycle continues until all target temperature points are detected.

[0035] In this embodiment of the invention, the current operating temperature of the battery under test is acquired in real time by a temperature sensor, the current target temperature is determined according to a preset temperature sequence, the heater switching duty cycle is calculated based on the difference between the current operating temperature and the current target temperature, and active closed-loop temperature control is implemented according to the duty cycle. This achieves active, orderly, multi-temperature point temperature regulation of the solar cell under on-orbit conditions, overcoming the shortcomings of traditional on-orbit tests that can only passively rely on the natural temperature of the solar panel and cannot conduct systematic testing under various temperature conditions. This enables subsequent forward and reverse IV scans to be stably executed at multiple preset temperature points, improving the comprehensiveness and accuracy of on-orbit performance testing.

[0036] Optionally, determining the switching duty cycle of the heater based on the current operating temperature and the current target temperature includes: When the current operating temperature is lower than the current target temperature, the previous target temperature in the preset temperature sequence that is before the current target temperature is obtained, and the switch duty cycle is determined based on the previous target temperature, the current operating temperature, and the current target temperature. When the current operating temperature reaches the current target temperature, the switch duty cycle is set to 0.

[0037] Specifically, when determining the switching duty cycle of the heater, the current operating temperature T is first determined. now Compared with the current target temperature T set The magnitude relationship. When the current operating temperature is lower than the current target temperature, it indicates that the tested solar cell has not yet reached the preset target temperature point and needs to continue heating. At this time, the previous target temperature T, which is located before the current target temperature, is obtained from the preset temperature sequence. init The previous target temperature and the current target temperature together define the temperature range corresponding to the current heating stage, reflecting the range that the temperature needs to cross under the combined effect of natural heating of the sail and active heating of the heater during this heating stage. After obtaining the above three temperature values, the heater's switching duty cycle D... heat Determine according to the following formula: ; Based on the above formula, the switching duty cycle decreases linearly as the current operating temperature increases. When the current operating temperature approaches the previous target temperature, the molecule approaches 0, the switching duty cycle approaches 1, and the heater operates at near full power to rapidly heat up. As the current operating temperature gradually increases and approaches the current target temperature, the molecule approaches (T... now - T init As the switch duty cycle approaches 0, the heating power gradually decreases to prevent temperature overshoot; when the current operating temperature reaches the current target temperature, i.e., T... now =T set With the switch duty cycle at 0, the heater completely stops heating, and the tested solar cell gradually stabilizes at the current target temperature through its own thermal equilibrium. (Combined with...) Figure 3 As shown, in the initial stage when the satellite moves from the shadow area to the illuminated area, the solar panel temperature is relatively low. The heater actively heats the tested solar cell with a large duty cycle, causing the temperature to rise rapidly. When the temperature reaches the first target temperature in the preset temperature sequence (e.g., -60°C), the heater stops heating (duty cycle drops to 0), and the solar cell stabilizes near this target temperature after passive thermal equilibrium. Figure 3The first forward and reverse scan period is marked, indicating that two IV scans are performed in both directions during this period. After the scan is completed, the heater restarts, the duty cycle returns to a higher value, and heating continues, pushing the temperature up to the next target temperature (e.g., -40℃). Heating then stops again, and forward and reverse scans are performed once more. The switching duty cycle decreases linearly as the current operating temperature increases.

[0038] In addition, combined Figure 3 As shown, when the solar panel temperature has risen to a higher temperature range, for example, when the current operating temperature reaches above 120℃, the heating process tends to reach equilibrium. At this point, high-temperature control needs to be implemented, that is, the heating belt is fully open to raise the solar panel temperature to the target temperature. Near the target temperature, the duty cycle of the heating belt switch is: ; The heater initially operates at full power, forcing the tested solar cell to reach a temperature close to the target temperature; the current operating temperature T... now Below the current target temperature T set The difference between the temperature control accuracy lower limit and the lower limit (i.e., T) now ≤T set At -1℃, the heating element is turned on at full power with a duty cycle of 1, using maximum heating power to overcome radiative heat loss in the high-temperature section and drive the temperature up; the current operating temperature T now Reaching and exceeding the sum of the current target temperature and the upper limit of temperature control accuracy (i.e., T) now ≥T set When the temperature reaches ±1℃, the heating element is completely turned off, the duty cycle of the switch is 0, and the temperature slowly drops by relying on the radiation of the sail itself into the space. When the temperature drops below the target temperature, the heater is turned on again at full power. In this way, a natural thermal cycle oscillation is formed within the range of ±1℃ of the target temperature, and the temperature fluctuation is controlled within a narrow range of less than 2℃.

[0039] The heating element is temperature-controlled within ±1℃ of the target temperature. The criterion for entering the new control logic is: ; Where p is the heating rate, T old The current operating temperature T now The temperature 1 second ago, ,by The heating rate is recorded periodically. Combined with... Figure 3 As shown, once the forward and reverse scanning of the high-temperature section is completed, the solar cell can return to the equilibrium temperature.

[0040] In this embodiment of the invention, by switching to a dual-threshold hysteresis control mode with a target temperature ±1℃ as the threshold in the high-temperature section, the heater is fully turned on below the lower limit of the target temperature and fully turned off above the upper limit of the target temperature. This overcomes the defect that the heating power of the linear duty cycle control is insufficient due to radiative heat dissipation in the high-temperature section, which prevents effective temperature rise. This ensures the reliable arrival of each target temperature point in the high-temperature section of the preset temperature sequence. At the same time, the temperature fluctuation is controlled within 2℃ by natural thermal oscillation within the hysteresis interval, providing stable and repeatable temperature conditions for forward and reverse IV scanning in the high-temperature section. This further broadens the on-orbit detectable temperature range of the solar cell, thereby improving the integrity and reliability of on-orbit performance testing across the entire temperature range.

[0041] Optionally, the step of adjusting the operating voltage of the solar cell under test through the voltage adjustment module to control the operating point of the solar cell under test to perform forward and reverse scanning includes: The voltage regulation module increases the operating voltage of the solar cell under test from the voltage value corresponding to the short circuit state to the voltage value corresponding to the open circuit state, and controls the operating point of the solar cell under test to perform a forward scan from the short circuit state to the open circuit state along the voltage increase direction. Furthermore, the voltage regulation module reduces the operating voltage of the solar cell under test from the voltage value corresponding to the open circuit state to the voltage value corresponding to the short circuit state, and controls the operating point of the solar cell under test to perform a reverse scan from the open circuit state to the short circuit state along the voltage decreasing direction.

[0042] Specifically, the forward and reverse scanning actively adjust the operating voltage applied to the terminals of the solar cell under test through a voltage regulation module. During forward scanning, the operating voltage is gradually increased from the voltage value corresponding to the short-circuit state (i.e., the output voltage approaches 0) to the voltage value corresponding to the open-circuit state (i.e., the output current approaches 0). During this process, the operating point of the tested cell continuously moves along the IV curve from the short-circuit current point to the open-circuit voltage point. Conversely, during reverse scanning, the operating voltage is gradually decreased from the voltage value corresponding to the open-circuit state to the voltage value corresponding to the short-circuit state. The operating point continuously moves along the IV curve from the open-circuit voltage point to the short-circuit current point. In a preferred embodiment of the invention, each time the operating voltage is changed, the ADC acquisition chip obtains the current voltage value through the voltage divider resistor before the diode, and the INA series current sampling chip obtains the current current value, thereby forming a voltage-current data pair, which constitutes the forward IV characteristic data and the reverse IV characteristic data at the target temperature. Through the above two complete forward and reverse voltage range scans, the detection covers the complete voltage range from short-circuit to open-circuit and from open-circuit to short-circuit, ensuring the acquisition of the full picture of the IV characteristic curve and each characteristic parameter.

[0043] In this embodiment of the invention, the voltage adjustment module gradually increases the operating voltage from the voltage value corresponding to the short-circuit state to the voltage value corresponding to the open-circuit state to complete the forward scan, and gradually decreases the voltage value corresponding to the open-circuit state to the voltage value corresponding to the short-circuit state to complete the reverse scan. This achieves a full forward and reverse scan of the complete voltage range of the solar cell under on-orbit conditions, ensuring the acquisition of the full picture of the IV characteristic curve and each characteristic parameter. Furthermore, by comparing the forward and reverse scan data, a comparable data basis with the same temperature conditions and the same sampling benchmark is provided for the quantitative characterization of the hysteresis effect, ultimately improving the accuracy of hysteresis effect assessment in on-orbit performance testing of the battery.

[0044] Optionally, the voltage regulation module includes a boost circuit, the input of which is connected to the solar cell under test, and the output of which is connected to the satellite bus. The step of adjusting the operating voltage of the solar cell under test through the voltage adjustment module to control the operating point of the solar cell under test to perform forward and reverse scanning includes: The operating voltage of the solar cell under test is adjusted by the output duty cycle of the boost circuit, and the operating point of the solar cell under test is controlled to perform forward and reverse scanning.

[0045] Specifically, the voltage regulation module uses a boost circuit as the execution component. The input of the boost circuit is connected to the solar cell under test, and the output is connected to the satellite bus via an isolation diode. The isolation diode utilizes its unidirectional conduction characteristic to ensure that current flows only from the photovoltaic module side to the satellite bus side, preventing reverse current from flowing into the solar cell under test. This avoids backflow of bus current interfering with the true output characteristics of the tested cell and causing distortion of the acquired voltage and current data. Furthermore, it blocks the path of fault current propagation to the bus in the event of a short circuit or other fault in the tested sample, ensuring the safety of the entire satellite power system. During forward and reverse scanning, the operating voltage of the solar cell under test is adjusted by controlling the output duty cycle of the boost circuit. The output voltage of the boost circuit is directly proportional to the duty cycle of its power switch; therefore, by changing the duty cycle, the operating voltage applied to the terminals of the tested cell can be continuously and accurately changed.

[0046] In a preferred embodiment of the present invention, during forward scanning, the output duty cycle of the boost circuit gradually increases from 0.1 to 0.9, corresponding to an increase in output voltage from the near-zero short-circuit state to the open-circuit state. During this process, the operating point of the battery under test gradually moves along the IV curve from the short-circuit current point to the open-circuit voltage point, and the current voltage and current values ​​are acquired and recorded as data pairs. During reverse scanning, the output duty cycle decreases from 0.9 to 0.1, corresponding to a gradual decrease in output voltage from the open-circuit state to the short-circuit state. The operating point moves in the reverse direction along the IV curve from the open-circuit voltage point to the short-circuit current point, and voltage and current data pairs are acquired and recorded at each step. The duty cycle adjustment range is limited to between 0.1 and 0.9. The lower limit of 0.1 ensures that the boost circuit can operate stably and that the output voltage is low enough to approach the short-circuit state for accurate short-circuit current measurement. The upper limit of 0.9 ensures that the boost circuit does not enter the extreme duty cycle region to avoid runaway and that the output voltage is high enough to approach the open-circuit state for accurate open-circuit voltage measurement.

[0047] In this embodiment of the invention, by using a boost circuit as the execution component of the voltage regulation module and its output duty cycle as the means of adjusting the working voltage, continuous, accurate, and rapid adjustment of the working voltage of the tested solar cell under on-orbit conditions is achieved. This allows forward and reverse scans to complete the full voltage range coverage from short circuit to open circuit and from open circuit to short circuit within a preset time period. At the same time, the electrical decoupling between the tested cell and the entire satellite bus is achieved through isolation diodes to ensure system safety. This provides a reliable and efficient hardware execution basis for the acquisition of complete IV characteristic data at each target temperature and the comparative analysis of hysteresis effects, ultimately improving the efficiency and accuracy of on-orbit performance testing of solar cells.

[0048] Optionally, adjusting the operating voltage of the tested solar cell by means of the output duty cycle of the boost circuit includes: For forward scanning, by controlling the output duty cycle to gradually increase from a first preset value to a second preset value in a preset step size, the operating voltage of the tested solar cell is increased from the voltage value corresponding to the short circuit state to the voltage value corresponding to the open circuit state. For reverse scanning, by controlling the output duty cycle to gradually decrease from the second preset value to the first preset value with the preset step size, the operating voltage of the tested solar cell is reduced from the voltage value corresponding to the open circuit state to the voltage value corresponding to the short circuit state.

[0049] Specifically, symmetrical duty cycle control strategies are employed for both forward and reverse scanning. In a preferred embodiment of the invention, the first preset value is a lower limit of 0.1 for duty cycle adjustment, the second preset value is an upper limit of 0.9 for duty cycle adjustment, and the preset step size is 1‰ of the change in duty cycle for each adjustment. The lower limit of 0.1 is set to ensure that the boost circuit can operate stably within the non-limit duty cycle range, avoiding output voltage instability caused by excessively low duty cycle leading to short power transistor conduction time, while ensuring the output voltage is low enough to approach a short-circuit state, thus enabling accurate measurement of the short-circuit current. The upper limit of 0.9 is set to ensure that the boost circuit does not enter the limit duty cycle region to avoid power transistor drive runaway, while ensuring the output voltage is high enough to approach an open-circuit state, thus enabling accurate measurement of the open-circuit voltage. The step size of 1‰ can obtain 800 sampling points across the entire range, sufficient to depict the complete contour of the IV curve and ensure accurate extraction of each characteristic parameter. During forward scanning, the output duty cycle gradually increases from 0.1 to 0.9 in preset steps of 1‰. Since the output voltage of the boost circuit is proportional to the duty cycle of its power switch, the operating voltage applied to the battery under test also increases accordingly from the voltage value corresponding to the near-zero short-circuit state to the voltage value corresponding to the near-zero output current open-circuit state. During reverse scanning, the output duty cycle gradually decreases from 0.9 to 0.1 in the same preset steps, and the operating voltage applied to the battery under test decreases continuously from the voltage value corresponding to the open-circuit state to the voltage value corresponding to the short-circuit state.

[0050] In this embodiment, during reverse scanning, the formula for adjusting the output duty cycle of the boost circuit is: ; During forward scanning, the formula for adjusting the output duty cycle of the boost circuit is: ; Among them, D boost To output the duty cycle, t is the time step index; In this embodiment of the invention, by symmetrically adjusting the duty cycle of the forward scan control output from 0.1 to 0.9 and the reverse scan control output duty cycle from 0.9 to 0.1, a full forward and reverse scan of the complete voltage range between the short-circuit and open-circuit states of the tested solar cell under on-orbit conditions is achieved. This allows the detection to cover the complete outline of the IV curve and ensures the accurate acquisition of each characteristic parameter. At the same time, a sufficiently dense sampling point is obtained through a step size of 1‰ to finely depict the curve shape. This provides a reliable data basis for the accurate comparison of the forward and reverse IV curves under the same voltage reference and the quantitative analysis of the hysteresis effect, ultimately improving the accuracy of hysteresis effect assessment in the on-orbit performance testing of solar cells.

[0051] Optionally, during the forward and reverse scanning process, acquiring the voltage and current values ​​corresponding to the operating point includes: During the forward and reverse scanning process, when the output duty cycle of the boost circuit changes once according to the preset step size and reaches the duty cycle corresponding to the current step, the voltage and current values ​​corresponding to the current operating point of the solar cell under test are obtained.

[0052] Specifically, when the output duty cycle of the boost circuit changes according to a preset step size and reaches the duty cycle value corresponding to the current step, the voltage value corresponding to the current operating point is obtained through a voltage divider resistor placed before the isolation diode. This voltage divider resistor is used to divide the high voltage output by the battery and send it to the voltage sampling channel of the ADC acquisition chip to realize the acquisition of the voltage signal. At the same time, the current value corresponding to the current operating point is obtained through an INA series current sampling chip. This current sampling chip is connected in series in the current output circuit of the battery under test, which can detect the battery current flowing into the satellite bus with high precision. The current signal is converted into a voltage signal and then sent to the current sampling channel of the ADC acquisition chip. After the voltage signal and current signal are synchronously converted into digital quantities by the ADC acquisition chip, the main control module associates and stores the current voltage value and current value as a data pair. The above data acquisition process is repeated during the forward scan: starting with a duty cycle of 0.1, a duty cycle increment (1‰) is completed every 1ms, and data is acquired after stabilizing at the new duty cycle, until the duty cycle reaches 0.9, resulting in 800 data pairs. The same process is repeated during the reverse scan: starting with a duty cycle of 0.9, a duty cycle decrement (1‰) is completed every 1ms, and data is acquired after stabilizing at the new duty cycle, until the duty cycle returns to 0.1, again yielding 800 data pairs. After each duty cycle change, the boost circuit output voltage undergoes a very short transient process before reaching a new steady-state value. The acquisition action is performed after the duty cycle reaches the corresponding value of the current step, rather than during the change process, ensuring that the acquired voltage and current values ​​accurately reflect the steady-state output characteristics at the operating point rather than transient values ​​during the transition process. Simultaneously, voltage and current acquisition are performed synchronously by the same ADC chip, guaranteeing a strict temporal correspondence between voltage and current values ​​at the same operating point.

[0053] In this embodiment of the invention, by synchronously acquiring the voltage and current values ​​of the current operating point after the duty cycle of the boost circuit output changes according to a preset step size and reaches the corresponding value of the current step, the synchronous acquisition of voltage and current data during forward and reverse scanning is realized, ensuring the strict correspondence between voltage and current values ​​in time in each set of data and that the acquired data reflects the steady-state rather than transient output characteristics of the operating point.

[0054] Optionally, obtaining the forward IV characteristic data and reverse IV characteristic data of the tested solar cell at each target temperature based on the voltage and current values ​​corresponding to the operating point includes: The voltage and current values ​​corresponding to each operating point collected during the forward scanning process are arranged in ascending order of voltage value to construct the forward IV characteristic data at the target temperature; The voltage and current values ​​corresponding to each operating point collected during the reverse scanning process are arranged in descending order of voltage value to construct the reverse IV characteristic data at the target temperature.

[0055] Specifically, when constructing IV characteristic data based on the collected voltage and current values, the raw data collected during forward and reverse scans are processed according to different sorting rules. During the forward scan, the output duty cycle of the boost circuit gradually increases with a preset step size, and the operating voltage applied to the tested solar cell continuously increases from the voltage value corresponding to the short-circuit state (close to 0V) to the voltage value corresponding to the open-circuit state. The voltage and current values ​​of each operating point are stored sequentially according to the acquisition order. In order to form a standardized IV characteristic curve, these data are rearranged in order of voltage value from low to high. The voltage value of all data pairs collected throughout the forward scan is used as the sorting key, and all data pairs are rearranged in ascending order of voltage value from small to large. After ascending sorting, the voltage value starts from the short-circuit voltage close to 0V and increases sequentially to the open-circuit voltage, while the current value starts from the short-circuit current and decreases accordingly with the voltage increase to close to 0A, thus forming a forward IV characteristic curve that continuously changes from the short-circuit point to the open-circuit point, reflecting the output characteristics of the tested cell in the direction of voltage increase. During the reverse scan, the output duty cycle gradually decreases in preset steps, and the operating voltage continuously decreases from the voltage value corresponding to the open circuit state to the voltage value corresponding to the short circuit state. The main control module also stores the data of each operating point sequentially according to the acquisition order. In order to form a reverse IV characteristic curve, these data are rearranged in descending order of voltage value. The voltage value of all data pairs acquired during the entire reverse scan is used as the sorting key, and all data pairs are rearranged in descending order of voltage value. After the descending sort, the voltage value starts from the open circuit voltage and decreases sequentially to the short circuit voltage, while the current value starts from near 0A and increases accordingly as the voltage decreases to the short circuit current. This forms a reverse IV characteristic curve that continuously changes from the open circuit point to the short circuit point, reflecting the output characteristics of the tested battery in the direction of voltage decrease.

[0056] In this embodiment of the invention, by arranging the data collected during the forward scan in ascending order of voltage value to construct forward IV characteristic data, and arranging the data collected during the reverse scan in descending order of voltage value to construct reverse IV characteristic data, the standardization of the original data of forward and reverse scans is realized. This enables the two sets of IV characteristic data to have clear physical meanings and corresponding comparable relationships on the voltage axis, thereby providing a standardized data foundation for the feature parameters extracted from the forward and reverse IV curves at each temperature point.

[0057] Optionally, the hysteresis analysis and degradation analysis based on the forward IV characteristic data and reverse IV characteristic data at each target temperature to obtain the on-orbit performance test data of the tested solar cell includes: The corresponding open-circuit voltage, short-circuit current, maximum power point voltage, and maximum power point current are extracted from the forward IV characteristic data and the reverse IV characteristic data at each target temperature, respectively. Based on the open-circuit voltage, short-circuit current, maximum power point voltage, and maximum power point current corresponding to the forward IV characteristic data and the reverse IV characteristic data, the open-circuit voltage difference ratio, short-circuit current difference ratio, maximum power point voltage difference ratio, and maximum power point current difference ratio are determined to obtain the hysteresis effect characterization parameters at each target temperature. After each forward and reverse scan for each target temperature in the preset temperature sequence is completed, the detection count is updated, and the number of orbital runs corresponding to the forward and reverse scans at the target temperature is determined based on the updated detection count. By correlating the forward IV characteristic data and reverse IV characteristic data at each target temperature with the corresponding number of orbital runs, the performance degradation data of the tested solar cell under different number of orbital runs can be obtained. The hysteresis effect characterization parameters and performance degradation data at all target temperatures are used as the on-orbit performance detection data.

[0058] Specifically, when performing hysteresis and degradation analyses based on forward and reverse IV characteristic data at each target temperature, characteristic parameters are first extracted from the forward and reverse IV characteristic data at each target temperature: open-circuit voltage, short-circuit current, maximum power point voltage, and maximum power point current. Open-circuit voltage refers to the voltage across the tested solar cell when the output current is zero, obtained from the data point in the IV characteristic data where the voltage is highest and the current approaches zero. Short-circuit current refers to the output current of the tested cell when the output voltage is zero, obtained from the data point in the IV characteristic data where the voltage approaches zero and the current is highest. The maximum power point voltage and maximum power point current are calculated by performing power calculations on the IV characteristic data (power equals the product of voltage and current); the voltage and current values ​​corresponding to the maximum power are the maximum power point voltage and maximum power point current. After obtaining the aforementioned characteristic parameters corresponding to the forward and reverse IV characteristic data, for each parameter, the difference ratio between the forward and reverse scans is calculated. This is the percentage obtained by dividing the absolute value of the difference between the parameter's value in the forward scan and its value in the reverse scan by the parameter's value in the forward scan. This yields the open-circuit voltage difference ratio, short-circuit current difference ratio, maximum power point voltage difference ratio, and maximum power point current difference ratio. These four difference ratios together constitute the hysteresis effect characterization parameters at the target temperature, quantitatively reflecting the degree of difference in forward and reverse output characteristics caused by the battery's internal ion migration behavior at that target temperature. Regarding decay analysis, the detection count is automatically updated after each forward and reverse scan of all target temperatures in the preset temperature sequence. For example, the count increments by 1 after each complete detection cycle. The detection count corresponds to the number of orbital runs. Since the detection is performed periodically on a fixed orbit, each detection cycle corresponds to a certain number of orbital runs. Therefore, the number of orbital runs corresponding to the current detection can be deduced from the detection count. Subsequently, the forward and reverse IV characteristic data at each target temperature are correlated and stored with the number of orbital runs corresponding to that round of testing. After accumulating data from multiple rounds of testing, trend data on the changes of each characteristic parameter at the same target temperature with increasing orbital runs can be obtained, i.e., performance degradation data. The hysteresis effect characterization parameters and performance degradation data at all target temperatures are summarized as the on-orbit performance testing data of the tested solar cell. This data can be transmitted back to the host onboard computer via the CAN bus by the controller, and then returned to the ground via the telemetry channel for analysis and evaluation by ground personnel. Furthermore, to prevent the loss of test counts due to abnormalities such as controller resets, these test counts are periodically saved via the onboard computer to ensure the persistence and reliability of the count information.

[0059] In this embodiment of the invention, open-circuit voltage, short-circuit current, maximum power point voltage and current are extracted from forward and reverse IV data at each temperature point, and the forward and reverse difference ratio is calculated to quantitatively characterize the hysteresis effect at each temperature point. At the same time, by correlating the detection count with the number of orbital runs, the detection data of each round is correlated with the on-orbit service time to obtain performance degradation data. This realizes a systematic on-orbit evaluation of battery hysteresis characteristics and long-term degradation laws, so that the detection results have multi-dimensional information including temperature dimension, hysteresis characteristics and long-term change trend, thereby providing comprehensive, quantitative and reliable direct data support for the engineering decision-making of battery space applications.

[0060] Combination Figure 4 As shown, another embodiment of the present invention provides a solar cell on-orbit performance testing system for testing the on-orbit performance of a photovoltaic module on a satellite solar panel. The photovoltaic module includes a solar cell under test, a heater, and a temperature sensor. The photovoltaic module is connected to the satellite bus via a voltage regulation module. The system includes: A temperature control unit is used to acquire the operating temperature of the solar cell under test through the temperature sensor, and to control the heater to control the temperature of the solar cell under test according to a preset temperature sequence. The on-orbit performance testing unit is used to perform on-orbit performance testing on the solar cell under test when the operating temperature reaches and stabilizes at each target temperature in the preset temperature sequence. Specifically, at each target temperature, the operating voltage of the solar cell under test is adjusted by the voltage regulation module to control the operating point of the solar cell under test to perform forward and reverse scanning; during the forward and reverse scanning process, the voltage and current values ​​corresponding to the operating point are collected, and based on the voltage and current values ​​corresponding to the operating point, the forward IV characteristic data and reverse IV characteristic data of the solar cell under test at each target temperature are obtained. The data analysis unit is used to perform hysteresis analysis and degradation analysis based on the forward IV characteristic data and reverse IV characteristic data at each target temperature to obtain the on-orbit performance test data of the solar cell under test.

[0061] The solar cell on-orbit performance testing system of the present invention has the same advantages over the prior art as the above-mentioned solar cell on-orbit performance testing method, and will not be repeated here.

[0062] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for on-orbit performance testing of solar cells, characterized in that, This is used to perform on-orbit performance testing on photovoltaic modules on satellite solar panels. The photovoltaic module includes a solar cell under test, a heater, and a temperature sensor. The photovoltaic module is connected to the satellite bus via a voltage regulation module. The method includes: The temperature sensor is used to obtain the operating temperature of the solar cell under test, and the heater is controlled to control the temperature of the solar cell under test according to a preset temperature sequence. When the operating temperature reaches and stabilizes at each target temperature in the preset temperature sequence, the on-orbit performance of the solar cell under test is tested. Specifically, at each target temperature, the operating voltage of the solar cell under test is adjusted by the voltage regulation module to control the operating point of the solar cell under test to perform forward and reverse scanning; during the forward and reverse scanning process, the voltage and current values ​​corresponding to the operating point are collected, and based on the voltage and current values ​​corresponding to the operating point, the forward IV characteristic data and reverse IV characteristic data of the solar cell under test at each target temperature are obtained. Hysteresis and degradation analyses are performed based on the forward IV characteristic data and reverse IV characteristic data at each target temperature to obtain the on-orbit performance test data of the solar cell under test.

2. The method for on-orbit performance testing of solar cells according to claim 1, characterized in that, The step of acquiring the operating temperature of the solar cell under test through the temperature sensor and controlling the heater to control the temperature of the solar cell under test according to a preset temperature sequence includes: The current operating temperature of the solar cell under test is obtained through the temperature sensor. Based on the current operating temperature, determine the current target temperature from the target temperatures in the preset temperature sequence; Based on the current operating temperature and the current target temperature, determine the switching duty cycle of the heater; The temperature of the solar cell under test is controlled based on the switching duty cycle of the heater.

3. The method for on-orbit performance testing of solar cells according to claim 2, characterized in that, Determining the switching duty cycle of the heater based on the current operating temperature and the current target temperature includes: When the current operating temperature is lower than the current target temperature, the previous target temperature in the preset temperature sequence that is before the current target temperature is obtained, and the switch duty cycle is determined based on the previous target temperature, the current operating temperature, and the current target temperature. When the current operating temperature reaches the current target temperature, the switch duty cycle is set to 0.

4. The method for on-orbit performance testing of solar cells according to claim 1, characterized in that, The step of adjusting the operating voltage of the solar cell under test through the voltage adjustment module to control the operating point of the solar cell under test to perform forward and reverse scanning includes: The voltage regulation module increases the operating voltage of the solar cell under test from the voltage value corresponding to the short circuit state to the voltage value corresponding to the open circuit state, and controls the operating point of the solar cell under test to perform a forward scan from the short circuit state to the open circuit state along the voltage increase direction. Furthermore, the voltage regulation module reduces the operating voltage of the solar cell under test from the voltage value corresponding to the open circuit state to the voltage value corresponding to the short circuit state, and controls the operating point of the solar cell under test to perform a reverse scan from the open circuit state to the short circuit state along the voltage decreasing direction.

5. The method for on-orbit performance testing of solar cells according to claim 1, characterized in that, The voltage regulation module includes a boost circuit, the input of which is connected to the solar cell under test, and the output of which is connected to the satellite bus. The step of adjusting the operating voltage of the solar cell under test through the voltage adjustment module to control the operating point of the solar cell under test to perform forward and reverse scanning includes: The operating voltage of the solar cell under test is adjusted by the output duty cycle of the boost circuit, and the operating point of the solar cell under test is controlled to perform forward and reverse scanning.

6. The method for on-orbit performance testing of solar cells according to claim 5, characterized in that, The step of adjusting the operating voltage of the solar cell under test by means of the output duty cycle of the boost circuit includes: For forward scanning, by controlling the output duty cycle to gradually increase from a first preset value to a second preset value in a preset step size, the operating voltage of the tested solar cell is increased from the voltage value corresponding to the short circuit state to the voltage value corresponding to the open circuit state. For reverse scanning, by controlling the output duty cycle to gradually decrease from the second preset value to the first preset value with the preset step size, the operating voltage of the tested solar cell is reduced from the voltage value corresponding to the open circuit state to the voltage value corresponding to the short circuit state.

7. The method for on-orbit performance testing of solar cells according to claim 6, characterized in that, During the forward and reverse scanning process, the voltage and current values ​​corresponding to the operating point are collected, including: During the forward and reverse scanning process, when the output duty cycle of the boost circuit changes once according to the preset step size and reaches the duty cycle corresponding to the current step, the voltage and current values ​​corresponding to the current operating point of the solar cell under test are obtained.

8. The method for on-orbit performance testing of solar cells according to claim 7, characterized in that, The step of obtaining the forward IV characteristic data and reverse IV characteristic data of the tested solar cell at each target temperature based on the voltage and current values ​​corresponding to the operating point includes: The voltage and current values ​​corresponding to each operating point collected during the forward scanning process are arranged in ascending order of voltage value to construct the forward IV characteristic data at the target temperature; The voltage and current values ​​corresponding to each operating point collected during the reverse scanning process are arranged in descending order of voltage value to construct the reverse IV characteristic data at the target temperature.

9. The method for on-orbit performance testing of solar cells according to claim 1, characterized in that, Hysteresis and degradation analyses are performed based on the forward and reverse IV characteristic data at each target temperature to obtain the on-orbit performance test data of the tested solar cell, including: The corresponding open-circuit voltage, short-circuit current, maximum power point voltage, and maximum power point current are extracted from the forward IV characteristic data and the reverse IV characteristic data at each target temperature, respectively. Based on the open-circuit voltage, short-circuit current, maximum power point voltage, and maximum power point current corresponding to the forward IV characteristic data and the reverse IV characteristic data, the open-circuit voltage difference ratio, short-circuit current difference ratio, maximum power point voltage difference ratio, and maximum power point current difference ratio are determined to obtain the hysteresis effect characterization parameters at each target temperature. After each forward and reverse scan for each target temperature in the preset temperature sequence is completed, the detection count is updated, and the number of orbital runs corresponding to the forward and reverse scans at the target temperature is determined based on the updated detection count. By correlating the forward IV characteristic data and reverse IV characteristic data at each target temperature with the corresponding number of orbital runs, the performance degradation data of the tested solar cell under different number of orbital runs can be obtained. The hysteresis effect characterization parameters and performance degradation data at all target temperatures are used as the on-orbit performance detection data.

10. A solar cell on-orbit performance testing system, characterized in that, This is used to perform on-orbit performance testing on photovoltaic modules on satellite solar panels. The photovoltaic module includes a solar cell under test, a heater, and a temperature sensor. The photovoltaic module is connected to the satellite bus via a voltage regulation module. The system includes: A temperature control unit is used to acquire the operating temperature of the solar cell under test through the temperature sensor, and to control the heater to control the temperature of the solar cell under test according to a preset temperature sequence. The on-orbit performance testing unit is used to perform on-orbit performance testing on the solar cell under test when the operating temperature reaches and stabilizes at each target temperature in the preset temperature sequence. Specifically, at each target temperature, the operating voltage of the solar cell under test is adjusted by the voltage regulation module to control the operating point of the solar cell under test to perform forward and reverse scanning; during the forward and reverse scanning process, the voltage and current values ​​corresponding to the operating point are collected, and based on the voltage and current values ​​corresponding to the operating point, the forward IV characteristic data and reverse IV characteristic data of the solar cell under test at each target temperature are obtained. The data analysis unit is used to perform hysteresis analysis and degradation analysis based on the forward IV characteristic data and reverse IV characteristic data at each target temperature to obtain the on-orbit performance test data of the solar cell under test.

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