A thermal control management system and method for a lithium-ion battery pack of a high-orbit satellite

Abstract

The application discloses a high-orbit satellite lithium ion battery pack thermal control management system, which comprises a temperature measuring device, a heater and a management module; the temperature measuring device is used for outputting temperature information of different single batteries to the management module; the heater is used for heating the single batteries; the management module sets different temperature control thresholds during an earth shadow season and after the end of the earth shadow season, simultaneously receives the temperature information input by the temperature measuring device, and controls the heater according to the temperature control thresholds and the temperature information, so that the temperature of the single batteries is 12-16 DEG C during the satellite earth shadow season and is 0-4 DEG C after the end of the satellite earth shadow season, the battery pack is discharged and is not discharged for 48 hours continuously. The application further discloses a high-orbit satellite lithium ion battery pack thermal control management method, which is realized by using the above system. The application can realize autonomous control of the temperature of the battery pack in orbit, and meanwhile, the weight cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery technology, specifically relating to a thermal control system and method for a high-orbit satellite lithium-ion battery pack. Background Technology

[0002] Battery packs are critical components of a spacecraft's power subsystem, providing power to the satellite during periods of eclipse or insufficient sunlight. Lithium-ion battery packs (hereinafter referred to as "battery packs") have the significant advantage of high energy density and have become the third-generation energy storage power source for satellites. However, due to their electrochemical characteristics, lithium-ion battery packs have high requirements for operating temperature. Improper thermal control and temperature management can, at best, affect the cycle life of the battery pack and compromise its reliability, failing to meet the 15-year lifespan requirement for high-orbit satellites. At worst, it can lead to the battery pack malfunctioning or causing irreversible safety losses, impacting the safe operation of the satellite and the success or failure of the mission.

[0003] To meet the high power requirements of high-orbit satellites, battery banks are generally composed of several individual cells connected in series and parallel. The requirements for temperature and thermal management of battery banks mainly include two aspects: 1) During the satellite's shadow season, the battery bank performs charging and discharging operations, requiring an operating temperature generally within the range of 10–35℃; during the satellite's long illumination period, the battery bank does not participate in the overall satellite discharge and is in a resting state, generally requiring a battery bank temperature within the range of 0–10℃. Low-temperature storage is beneficial to the battery bank's performance; 2) Temperature consistency requirements: the maximum temperature difference between different individual cells within the same battery bank should be <5℃ to ensure the consistency of charging and discharging operations of each individual cell.

[0004] The current status of thermal control and temperature management for high-power lithium-ion battery packs in high-orbit satellites both domestically and internationally is as follows: 1) The operating temperature of the battery pack is generally achieved through heat pipe cooling, temperature acquisition by thermistors, and temperature control by heaters; 2) To ensure temperature consistency among different individual cells in the battery pack, thermal isolation measures are generally implemented by setting up a thermal control cover for the battery pack, thus isolating it from other individual units within the cabin. These methods suffer from drawbacks such as increased weight in the power subsystem, poor autonomy in battery pack temperature control, and poor temperature control consistency for high-power battery packs exceeding 10kW. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned defects and provide a thermal control management system and method for lithium-ion battery packs in high-orbit satellites. This invention solves the technical problem that the operating temperature of the battery pack cannot be automatically controlled according to the shadow season and the solar season, and further solves the technical problems of poor temperature uniformity of individual cells and increased weight of the thermal control management system. This invention can realize autonomous temperature control of the battery pack in orbit, while reducing the weight cost.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] A thermal control management system for lithium-ion battery packs in high-orbit satellites includes a temperature measuring device, a heater, and a management module;

[0008] Temperature measuring devices are installed on the outer surface of the casing of different individual batteries, and output the temperature information of different individual batteries to the management module;

[0009] The heater is used to heat the individual battery cells;

[0010] The management module sets different temperature control thresholds during and after the satellite shadow season. It also receives temperature information from the temperature measuring device and controls the heater according to the temperature control thresholds and temperature information, so that the temperature of the individual battery is between 12 and 16°C during the satellite shadow season and between 0 and 4°C after the satellite shadow season ends, the battery pack is discharged, and has not been discharged for 48 consecutive hours.

[0011] Furthermore, this also includes heat pipe networks;

[0012] The heat pipe network includes several horizontal heat pipes and several vertical heat pipes. The horizontal and vertical heat pipes are orthogonal to each other and are located inside the satellite compartment where the battery pack is installed. The heat pipe network is used to achieve heat transfer between adjacent cells.

[0013] Furthermore, this also includes OSR chips;

[0014] OSR sheets are attached to the outer surface of the satellite compartment panel where the battery pack is installed.

[0015] Furthermore, a thermal pad and a polyimide film are provided between the base plate of the battery pack and the satellite compartment panel, with the polyimide film located between the thermal pad and the satellite compartment panel;

[0016] The thickness of the polyimide film is 80–120 μm.

[0017] Furthermore, the battery pack is installed on the satellite module. The satellite module used to install the battery pack does not install other heat-dissipating satellite equipment and is coated with thermal control white paint.

[0018] An aluminum-plated film is pasted on the surface of the satellite compartment adjacent to the satellite compartment where the battery pack is installed.

[0019] Furthermore, the number of temperature measuring devices is ≥ 1 / 5 of the total number of individual cells in the battery pack;

[0020] The temperature measuring devices are evenly distributed in a zigzag pattern on the casings of different individual batteries.

[0021] Furthermore, the heater is disposed on the outer surface of the sleeve structure of the single-cell parallel module, and includes a main circuit and a backup circuit with the same structure;

[0022] Each circuit contains ≥10 heating elements connected in series;

[0023] The power of each circuit is 60-100W.

[0024] Furthermore, 72 hours before the start of the satellite shadow season, the primary loop temperature control threshold is 14–16°C;

[0025] 48 hours before the start of the satellite ground shadow season, the temperature control threshold for the backup circuit is 12-16℃.

[0026] After the satellite shadow season ends, the battery pack has finished discharging and has not been discharged for 48 consecutive hours, the temperature control threshold of the main circuit is 2-4℃, and the temperature control threshold of the backup circuit is 0-4℃.

[0027] Furthermore, the management module can set different temperature control thresholds during and after the shadow season, including:

[0028] The current time is 72 hours before the start of the satellite shadow season. Set the primary loop temperature control threshold to 14-16℃.

[0029] The current time is 48 hours before the start of the satellite shadow season. Set the backup circuit temperature control threshold to 12-16℃.

[0030] The current time is when the battery pack has finished discharging and has not been discharged for 48 consecutive hours. Set the temperature control threshold of the main circuit to 2-4℃ and the temperature control threshold of the backup circuit to 0-4℃.

[0031] A thermal control management method for lithium-ion battery packs in high-orbit satellites, implemented using the aforementioned system, includes:

[0032] The S1 temperature measuring device outputs the temperature information of different individual cells to the management module;

[0033] The S2 management module determines whether the current time is 72 hours before the start of the satellite shadow season;

[0034] If so, set the primary circuit temperature control threshold to 14-16℃ and proceed to step S3; otherwise, proceed to step S4.

[0035] The S3 management module determines whether the current time is 48 hours before the start of the satellite shadow season;

[0036] If so, set the backup circuit temperature control threshold to 12-16℃, and use the main circuit temperature control threshold, backup circuit temperature control threshold and temperature information to control the heater and adjust the temperature of the individual battery.

[0037] The S4 management module determines whether the current moment is when the battery pack has completed discharging and has not been discharged for 48 consecutive hours. If so, it sets the temperature control threshold of the main circuit to 2-4℃ and the temperature control threshold of the backup circuit to 0-4℃. It then uses the temperature control thresholds of the main circuit and the backup circuit, along with the temperature information, to control the heater and adjust the temperature of the individual battery cells.

[0038] Compared with the prior art, the present invention has at least one of the following advantages:

[0039] (1) This invention creatively proposes a thermal control management system for lithium-ion battery packs in high-orbit satellites, which can realize the autonomous switching of the temperature control threshold of the battery pack during the shadow season and the sunshine season, and realize the autonomous management of the temperature control of the battery pack in orbit without the need for ground command intervention.

[0040] (2) By designing the satellite compartment panel where the battery is installed, the present invention eliminates the thermal control cover of the battery pack and reduces the weight of the system;

[0041] (3) This invention proposes a heat pipe layout method suitable for high-power battery packs of high-orbit satellites, which solves the problem of high-power heat dissipation and high requirements for individual cell temperature consistency during battery pack discharge.

[0042] (4) The present invention proposes a scheme for setting up temperature measuring points and heaters for battery packs, which is beneficial to improving the accuracy of temperature monitoring and control of battery packs. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the heat pipe layout of the present invention;

[0044] Figure 2 This is a schematic diagram of the temperature measuring point layout of the present invention;

[0045] Figure 3 This is a schematic diagram of the heater of the present invention;

[0046] Figure 4 This is a flowchart of the on-orbit autonomous temperature management method for the battery pack of the present invention;

[0047] Figure 5 The temperature telemetry curve of the battery pack for the whole satellite thermal test;

[0048] Figure 6 The figures show the temperature telemetry curves of the on-orbit battery pack, where (a) is the temperature change curve from the solar season to the shadow season; and (b) is the temperature change curve from the shadow season to the solar season. Detailed Implementation

[0049] The features and advantages of the present invention will become clearer and more apparent from the following detailed description.

[0050] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0051] This invention proposes a thermal control management method for lithium-ion battery packs in high-orbit satellites, which solves the problems of refined thermal control design and autonomous temperature control of high-power battery packs, while reducing weight.

[0052] High-orbit satellites are typically equipped with two battery banks, each consisting of one to two modules. Taking a certain high-orbit satellite as an example, the battery banks are configured with two sets, one in the north and one in the south. Each set consists of two identical battery modules, A and B, connected in series. Each battery module consists of 3 parallel and 10 series cells. Each cell is installed in a battery sleeve structure. The different sleeve structures are interconnected to form the battery bank base plate. The battery bank is then mounted on the satellite cabin via the base plate.

[0053] The specific thermal design and management implementation methods of the battery pack are as follows:

[0054] Each battery pack, consisting of modules A and B, is laid out and installed on the same outer surface of the satellite mounting panel. This satellite mounting panel is referred to as the satellite mounting panel. A five-vertical, four-horizontal orthogonal heat pipe network is used to control the temperature uniformity between different individual cells within the same battery pack. The heat pipe network is embedded inside the satellite mounting panel, and the length of the heat pipes should exceed the mounting surface of the battery pack, exhibiting a uniform distribution as much as possible. Additionally, one longitudinal heat pipe should be placed in the middle area between two rows of individual cells. An OSR (Optical Solar Reflector) sheet is adhered to the entire outer surface of the satellite mounting panel for heat dissipation. A thermal pad is placed between the battery pack base plate and the satellite mounting panel, and a 100µm polyimide film is adhered between the thermal pad and the satellite mounting panel to achieve insulated installation of the battery pack structure and the satellite mounting panel, while ensuring necessary thermal conductivity and heat transfer performance. (See Appendix) Figure 1 .

[0055] The satellite mounting panel (satellite installation panel) used to install the battery pack does not house any other heat-dissipating satellite equipment besides the battery pack. The satellite mounting panel for the battery pack is coated with thermally controlling white paint; an aluminum-plated film is adhered to the surface of the adjacent satellite mounting panel, achieving thermal insulation between the battery mounting panel and other panels. Based on this design, the multi-layered heat insulation cover traditionally used for battery packs is eliminated.

[0056] Each module is equipped with at least 5 temperature measuring points, evenly distributed in a zigzag pattern on the casings of different individual cells, to achieve battery pack temperature monitoring. The thermistors used for temperature measurement are led to the battery pack connectors via cables, see Appendix. Figure 2 .

[0057] Each of the four battery modules (north and south) is equipped with a heater. Each battery module heater includes two circuits: a main circuit and a backup circuit. The resistance and connection method of the main and backup heaters are identical. Each heater consists of 10 heating elements connected in series, which are attached to the outer surface of the battery sleeve. Each heater circuit has a power of 60-100W. The main and backup heating elements are connected to the battery bank connectors via cables. The main and backup heaters are controlled by a heater control switch controlled by the space management software. The main and backup heaters are independently controlled. Under normal circumstances, the main circuit operates, while the backup circuit only operates when the main circuit fails. (See appendix) Figure 3 .

[0058] The management module can include a satellite computer equipped with power management and thermal control software to autonomously manage the battery pack temperature control during satellite in orbit. When the satellite software detects conditions such as 72 hours before the shadow season, 48 hours before the shadow season, and 48 consecutive hours without discharge after discharge, it automatically sets the temperature control thresholds for the main and backup heaters to meet the temperature requirements for battery pack operation and storage in orbit. It also enables autonomous switching between the shadow season and long sunshine periods without ground command intervention. (See appendix) Figure 4 According to Appendix 1, the in-ground shadow season is a warming process. The primary backup is turned on first and the backup is turned on later to avoid the problem of high power requirements when the primary and backup are turned on at the same time. The out-of-ground shadow season is a cooling process and there are no power requirements. Therefore, the primary and backup thresholds can be adjusted at the same time. As shown in Table 1, when the Star Service software detects the time in the first column, it will change the threshold to the threshold in the third column.

[0059] Table 1. Threshold settings for battery pack heaters

[0060]

[0061] During a thermal test on a high-orbit satellite equipped with the lithium-ion battery pack thermal control management system of this invention, the thermal control design and temperature control performance of the battery pack were verified. The operating temperature during charging and discharging was 12–16.5°C, with a maximum temperature difference of 2.1°C between individual cells, meeting the temperature requirements of the battery pack. (See attached image.) Figure 5 ;

[0062] After the launch of a high-orbit satellite, the thermal control design and temperature control of the battery pack were verified in orbit. During charging and discharging, the temperature ranged from 11.6 to 17.1°C, and during storage (non-operating state), the temperature ranged from 0.5 to 5.6°C. The maximum temperature difference between individual cells was 2.5°C, meeting the temperature requirements of the battery pack. (See attached image) Figure 6 The temperature during charging and discharging is equivalent to the temperature during the shadow season, and the temperature during rest is equivalent to the temperature during the sunshine season.

[0063] This invention is applicable to the domestic high-orbit satellite field and is suitable for the thermal control management of the battery pack in the power system of spacecraft equipped with high-power lithium-ion battery packs of 10kW or more as energy storage devices. The battery pack has good thermal control effect, and the temperature meets the requirements of the battery pack's operating temperature and maximum temperature difference. At the same time, it reduces the weight by at least 3kg compared with the traditional solution and has been verified by in-orbit flight, showing good economic benefits and promotion value.

[0064] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0065] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A thermal control management system for lithium-ion battery packs in high-orbit satellites, characterized in that, Includes temperature measuring device, heater, and management module; Temperature measuring devices are installed on the outer surface of the casing of different individual batteries, and output the temperature information of different individual batteries to the management module; The heater is used to heat the individual battery cells; The management module sets different temperature control thresholds during and after the satellite shadow season. It also receives temperature information from the temperature measuring device and controls the heater according to the temperature control thresholds and temperature information, so that the temperature of the individual battery is between 12 and 16°C during the satellite shadow season and between 0 and 4°C after the satellite shadow season ends, the battery pack is discharged, and has not been discharged for 48 consecutive hours.

2. The thermal control management system for a high-orbit satellite lithium-ion battery pack according to claim 1, characterized in that, It also includes heat pipe networks; The heat pipe network includes several horizontal heat pipes and several vertical heat pipes. The horizontal and vertical heat pipes are orthogonal to each other and are located inside the satellite compartment where the battery pack is installed. The heat pipe network is used to achieve heat transfer between adjacent cells.

3. The thermal control management system for a high-orbit satellite lithium-ion battery pack according to claim 1, characterized in that, Also includes OSR chips; OSR sheets are attached to the outer surface of the satellite compartment panel where the battery pack is installed.

4. The thermal control management system for a high-orbit satellite lithium-ion battery pack according to claim 1, characterized in that, A thermal pad and a polyimide film are installed between the base plate of the battery pack and the satellite compartment panel, with the polyimide film located between the thermal pad and the satellite compartment panel. The thickness of the polyimide film is 80–120 μm.

5. A thermal control management system for a high-orbit satellite lithium-ion battery pack according to claim 1, characterized in that, The battery pack is installed on the satellite module. The satellite module used to install the battery pack does not install other individual satellite equipment that consumes heat, and is coated with thermal control white paint. An aluminum-plated film is pasted on the surface of the satellite compartment adjacent to the satellite compartment where the battery pack is installed.

6. The thermal control management system for a high-orbit satellite lithium-ion battery pack according to claim 1, characterized in that, The number of temperature measuring devices is ≥ 1 / 5 of the total number of individual cells in the battery pack; The temperature measuring devices are evenly distributed in a zigzag pattern on the casings of different individual batteries.

7. The thermal control management system for a high-orbit satellite lithium-ion battery pack according to claim 1, characterized in that, The heater is located on the outer surface of the sleeve structure of the parallel module of the single cell, and includes a main circuit and a backup circuit with the same structure. Each circuit contains ≥10 heating elements connected in series; The power of each circuit is 60-100W.

8. A thermal control management system for a high-orbit satellite lithium-ion battery pack according to claim 7, characterized in that, The management module can set different temperature control thresholds during and after the shadow season, including the following methods: The current time is 72 hours before the start of the satellite shadow season. Set the primary loop temperature control threshold to 14-16℃. The current time is 48 hours before the start of the satellite shadow season. Set the backup circuit temperature control threshold to 12-16℃. The current time is the end of the satellite shadow season, the battery pack has finished discharging and has not been discharged for 48 consecutive hours. The temperature control threshold for the primary circuit is set to 2-4℃, and the temperature control threshold for the backup circuit is set to 0-4℃.

9. A thermal control management system for a high-orbit satellite lithium-ion battery pack according to claim 2, characterized in that, The heat pipe network is embedded inside the satellite mounting panel. The length of the heat pipes exceeds the mounting surface of the battery pack. The horizontal and vertical heat pipes in the heat pipe network are evenly distributed. One vertical heat pipe is set between two adjacent rows of individual cells.

10. A thermal control management method for lithium-ion battery packs in high-orbit satellites, characterized in that, The system is implemented using the system described in claim 7 or 8, comprising: The S1 temperature measuring device outputs the temperature information of different individual cells to the management module; The S2 management module determines whether the current time is 72 hours before the start of the satellite shadow season; If so, set the primary circuit temperature control threshold to 14-16℃ and proceed to step S3; otherwise, proceed to step S4. The S3 management module determines whether the current time is 48 hours before the start of the satellite shadow season; If so, set the backup circuit temperature control threshold to 12-16℃, and use the main circuit temperature control threshold, backup circuit temperature control threshold and temperature information to control the heater and adjust the temperature of the individual battery. The S4 management module determines whether the current moment is when the battery pack has completed discharging and has not been discharged for 48 consecutive hours. If so, it sets the temperature control threshold of the main circuit to 2-4℃ and the temperature control threshold of the backup circuit to 0-4℃. It then uses the temperature control thresholds of the main circuit and the backup circuit, along with the temperature information, to control the heater and adjust the temperature of the individual battery cells.

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