A wide-temperature-range thermal management method and system for power industry backup batteries

Abstract

This invention belongs to the field of battery management technology and discloses a wide-temperature-range thermal management method and system for backup batteries in the power industry. The method includes: acquiring the cell temperature, TEC cold-side temperature, and TEC hot-side temperature through a temperature acquisition module; determining the TEC's operating mode based on the cell temperature using a thermal management controller; controlling the TEC drive circuit to drive the TEC to operate according to the operating mode using the thermal management controller; adjusting the PWM duty cycle of the TEC drive circuit based on the deviation between the cell temperature and a preset target temperature to adjust the TEC's input power until the cell temperature reaches the preset target temperature; and employing a cold-start strategy, a low-SOC protection strategy, a TEC thermoelectric power recovery strategy, a pre-compensation strategy, and a control parameter configuration strategy for thermal management. This invention enables backup power supplies in the power industry to operate safely and reliably under extreme environmental temperatures and is compatible with various cell chemistry systems.

Description

Technical Field

[0001] This invention relates to the field of battery management technology, and in particular to a wide-temperature-range thermal management method and system for backup batteries in the power industry. Background Technology

[0002] Power distribution terminals, communication base stations, emergency power supplies for rail transit, and outdoor online monitoring equipment are critical devices deployed in large numbers in industrial infrastructure, all relying on backup batteries to maintain uninterrupted operation during mains power outages. These devices are generally deployed in outdoor environments with temperatures ranging from -40°C to 70°C. Currently, commonly used cell chemistry systems for industrial backup power supplies include lithium iron phosphate (LFP), ternary lithium (NCM / NCA), lithium titanate (LTO), and sodium-ion batteries, each with different operating temperature ranges. At high temperatures (>45°C), the internal resistance of various lithium-ion cells increases, side reactions intensify, and lifespan declines sharply, posing a risk of thermal runaway. At low temperatures (<0°C), the lithium-ion migration rate decreases, and lithium dendrite precipitation during charging can easily occur, leading to internal short circuits and a significant decrease in discharge capacity. Although lithium titanate and sodium-ion batteries have superior low-temperature performance, they still suffer from capacity decay and limited charging at extreme low temperatures (-40°C), requiring thermal management intervention as well.

[0003] Thermoelectric coolers (TECs) are based on the Peltier effect and can achieve bidirectional cooling / heating by changing the direction of the current. They have advantages such as no moving parts, compact size, high reliability, and precise temperature control, making them very suitable for the aforementioned industrial scenarios. However, existing TEC-based battery thermal management solutions have the following shortcomings: (1) no heat insulation structure is set up; (2) the TEC cold start problem at extreme low temperatures of -40℃ is not considered; (3) the temperature acquisition point is singular (only the battery temperature is collected); (4) there is a lack of low SOC (State of Charge) protection mechanism for industrial backup power scenarios; (5) it is not possible to be compatible with multiple cell chemical systems through a unified hardware platform; (6) it does not consider using the natural temperature difference formed by the heat insulation structure in environments with large day-night temperature differences for thermoelectric power generation recovery; (7) there is a lack of feedforward control based on ambient temperature prediction.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] The main objective of this invention is to provide a wide-temperature-range thermal management method and system for backup batteries in the power industry, aiming to solve the problems of existing TEC-based battery thermal management methods, such as difficulty in cold start at extreme low temperatures, lack of low SOC protection, incompatibility with multiple cell chemical systems, lack of thermoelectric power generation recovery, and lack of feedforward control.

[0006] To achieve the above-mentioned objective, this invention provides a wide-temperature-range thermal management method for backup batteries in the power industry, the method comprising: The temperature acquisition module acquires the cell temperature, TEC cold surface temperature, and TEC hot surface temperature of the backup battery in the power industry in real time. Based on the cell temperature and a preset temperature threshold, the thermal management controller determines the operating mode of the TEC, which includes a low-temperature heating mode, a normal standby mode, and a high-temperature cooling mode. According to the operating mode, the power supply direction of the TEC drive circuit is controlled by the thermal management controller to drive the TEC to operate according to the operating mode; Based on the deviation between the cell temperature and the preset target temperature, the PWM duty cycle of the TEC drive circuit is controlled by the thermal management controller to adjust the input power of the TEC until the cell temperature reaches the preset target temperature. Based on the cell temperature, the TEC cold surface temperature, and the TEC hot surface temperature, thermal management is performed on the power industry backup battery using a cold start strategy, a low SOC protection strategy, a TEC thermoelectric power generation recovery strategy, a pre-compensation strategy, and a control parameter configuration strategy.

[0007] Optionally, the preset temperature threshold includes a first preset temperature threshold and a second preset temperature threshold, wherein the first preset temperature threshold is less than the second preset temperature threshold; The step of determining the operating mode of the TEC (Chemical Temperature Controller) based on the cell temperature and a preset temperature threshold specifically includes: The operating mode of the TEC is determined by comparing the cell temperature with the first preset temperature threshold and the second preset temperature threshold using a thermal management controller. If the cell temperature is lower than the first preset temperature threshold, the TEC is determined to be in low-temperature heating mode. If the cell temperature is not less than the first preset temperature threshold and not greater than the second preset temperature threshold, the TEC is determined to be in normal standby mode. If the cell temperature is greater than the second preset temperature threshold, the TEC is determined to be in high-temperature cooling mode.

[0008] Optionally, the step of controlling the power supply direction of the TEC drive circuit through the thermal management controller according to the operating mode, so as to drive the TEC to operate according to the operating mode, specifically includes: When the operating mode of the TEC is determined to be low-temperature heating mode, the power supply direction of the TEC drive circuit is controlled to the first power supply direction by the thermal management controller, so as to drive the TEC to be in low-temperature heating mode. The TEC transfers heat to the battery cell and reduces the heat loss of the battery cell to the environment through the heat insulation structure. When the TEC is determined to be in normal standby mode, the thermal management controller controls the TEC drive circuit to stop supplying power, so that the TEC is in normal standby mode and the TEC stops working; When the operating mode of the TEC is determined to be high temperature cooling mode, the power supply direction of the TEC drive circuit is controlled to the second power supply direction by the thermal management controller, so as to drive the TEC to be in high temperature cooling mode. The TEC extracts heat from the battery cell and blocks ambient heat from entering the battery cell from the non-TEC covered surface through the heat insulation structure. The TEC is disposed on one side of the battery cell, and the heat insulation structure is disposed on the non-TEC covered side of the battery cell. The TEC and the heat insulation structure form a synergistic thermal management structure.

[0009] Optionally, when the cell temperature is below an extreme low temperature threshold, a cold start strategy is executed, the cold start strategy including: The TEC is preheated using a first preset low power ratio of its rated power as the heating power. When the first temperature difference between the hot surface temperature and the cold surface temperature of the TEC is lower than the thermal stress threshold, the heating power of the TEC is gradually increased to the rated power at a preset rate. When the first temperature difference is greater than the preset upper limit of temperature difference, the heating power of the TEC is paused; when the first temperature difference is less than the preset lower limit of temperature difference, the heating power of the TEC continues to be increased. During the execution of the cold start strategy, the battery management system locks the charging and discharging functions of the power industry backup battery. When the cell temperature is greater than the first preset unlocking temperature, the battery management system unlocks the charging function. When the cell temperature is greater than the second preset unlocking temperature, the battery management system unlocks the discharging function.

[0010] Optionally, the wide-temperature-range thermal management method for backup batteries in the power industry further includes a hardware over-temperature protection strategy, which includes: When the temperature of the TEC hot surface exceeds the preset hot surface protection threshold, the power supply to the TEC is cut off by a hardware comparator. When the cell temperature exceeds a preset cell protection threshold, the charging and discharging circuit of the power industry backup battery is cut off by the battery management system, so that the power industry backup battery enters a thermal protection state.

[0011] Optionally, the low SOC protection strategy includes: During the period when the TEC is in low-temperature heating mode, the SOC value of the power industry backup battery is monitored in real time by the thermal management controller; When the SOC value is lower than the first preset SOC threshold, the heating power of the TEC is reduced to a second preset low power ratio of the rated power; When the SOC value is lower than the second preset SOC threshold, the heating function of the TEC is turned off until the external charging is restored, at which point the heating function of the TEC is turned on again.

[0012] Optionally, the TEC (Thermoelectric Generating Recovery) strategy includes: When the ambient temperature is higher than the cell temperature and the second temperature difference between the ambient temperature and the cell temperature exceeds the preset TEG start-up threshold, the TEC is switched to thermoelectric power generation mode by the thermal management controller. In thermoelectric power generation mode, an electromotive force is generated by the temperature difference gradient formed between the heat insulation structure and the TEC. The TEC, as a thermoelectric power generation device, converts ambient heat into electrical energy. After being regulated by a DC-DC converter circuit, the electrical energy is used to additionally charge the power industry backup battery or maintain the battery management system at minimum power consumption. Based on the first temperature difference and the ambient temperature, query the pre-stored TEG output characteristic curve, and estimate the current recoverable power based on the TEG output characteristic curve. When the current recoverable power is greater than a preset ratio of the input power required by the TEC to offset the same heat flow in high-temperature cooling mode, the TEC preferentially operates in thermoelectric power generation mode. The TEG output characteristic curve is dynamically updated according to the TEC model, aging state, and cell chemical system identification.

[0013] Optionally, the pre-compensation strategy includes: Receive ambient temperature prediction data through the BMS communication interface; When the predicted ambient temperature data within a preset time period is less than the first preset temperature threshold or greater than the second preset temperature threshold, and the cell temperature is not less than the first preset temperature threshold and not greater than the second preset temperature threshold, the thermal management controller controls the TEC drive circuit to drive the TEC to enter the low-temperature heating mode or high-temperature cooling mode in advance.

[0014] Optionally, the wide-temperature-range thermal management method for backup batteries in the power industry further includes an adaptive optimization strategy, which includes: The adaptive COP optimizer built into the thermal management controller queries the pre-stored TEC characteristic parameter table based on the first temperature difference, the cell temperature, and the cell chemical system identifier. Obtain the target operating current or target PWM duty cycle that maximizes the instantaneous energy efficiency ratio (COP) of the TEC from the TEC characteristic parameter table; The thermal management controller controls the TEC drive circuit to operate at the target operating current or the target PWM duty cycle so that the instantaneous energy efficiency ratio (COP) of the TEC reaches its maximum value.

[0015] Optionally, the wide-temperature-range thermal management method for backup batteries in the power industry further includes an early warning strategy for thermal runaway and a TEC emergency suppression strategy, wherein the early warning strategy for thermal runaway and the TEC emergency suppression strategy includes: Based on the cell temperature, the TEC cold surface temperature and the TEC hot surface temperature, the cell temperature change rate, the first temperature difference change rate and the temperature gradient at different locations of the cell are calculated in real time. When the cell temperature change rate or the first temperature difference change rate is greater than the first preset warning threshold or the temperature gradient is greater than the second preset warning threshold, it is determined that there is an early risk of thermal runaway, and the TEC is switched to emergency suppression mode through the thermal management controller. In emergency suppression mode, the TEC actively cools the abnormal area of ​​the cell at maximum safe power, and disconnects the charging and discharging circuit of the power industry backup battery through the battery management system and reports an alarm.

[0016] Optionally, the wide-temperature-range thermal management method for backup batteries in the power industry further includes a temperature control strategy, which includes: The real-time instantaneous energy efficiency ratio (COP) of the TEC is calculated based on the first temperature difference. When the real-time instantaneous energy efficiency ratio (COP) is less than a preset COP threshold, the input power of the TEC is reduced or the TEC is switched to passive cooling mode by the thermal management controller. When the first temperature difference is greater than the preset reversal determination threshold, it is determined that the cooling direction of the TEC is reversed, and the power supply to the TEC is cut off by the thermal management controller; A temperature dead zone is set with the preset target temperature as the center. When the cell temperature is within the temperature dead zone, the thermal management controller maintains the input power of the TEC at a constant level. A first temperature hysteresis and a second temperature hysteresis are set based on the first preset temperature threshold and the second preset temperature threshold, respectively, to prevent the TEC from frequently switching working modes at the first preset temperature threshold or the second preset temperature threshold. The temperature control strategy architecture includes state machine control or continuous control, and the temperature control strategy algorithm includes PID closed-loop control, fuzzy control, ON-OFF hysteresis control, or lookup table method.

[0017] Optionally, the control parameter configuration strategy includes: Multiple sets of thermal management parameters corresponding to various cell chemical systems are pre-stored. Each set of thermal management parameters includes the first preset temperature threshold, the second preset temperature threshold, the extreme low temperature threshold, the first preset low power ratio, the thermal stress threshold, the preset rate, the preset upper limit of temperature difference, the preset lower limit of temperature difference, the first preset unlocking temperature, the second preset unlocking temperature, the preset hot surface protection threshold, the preset cell protection threshold, the first preset SOC threshold, the second preset low power ratio, the second preset SOC threshold, the preset TEG start-up threshold, the preset ratio, the preset future duration, the first preset warning threshold, the second preset warning threshold, the preset COP threshold, the preset reversal determination threshold, the first temperature hysteresis, and the second temperature hysteresis. Obtain the cell chemical system identifier corresponding to the backup battery for the power industry, and based on the cell chemical system identifier, call the target thermal management parameter group corresponding to the cell chemical system identifier from multiple pre-stored thermal management parameter groups; Thermal management of the power industry backup battery is performed through a thermal management controller based on the target thermal management parameter set. The battery cell chemistry system includes lithium iron phosphate batteries, ternary lithium batteries, lithium titanate batteries, and sodium-ion batteries. The thermal management parameter group supports online updates and configuration adjustments through the BMS communication interface.

[0018] To achieve the above-mentioned objectives, the present invention also provides a wide-temperature-range thermal management system for backup batteries in the power industry, the wide-temperature-range thermal management system for backup batteries in the power industry comprising: Backup batteries for the power industry are composed of cells connected in different series and parallel combinations. The TEC is disposed on the surface of the battery cell and is thermally coupled to the battery cell through a thermally conductive interface layer or a thermally conductive component or through direct contact. A thermal insulation structure is provided on the non-TEC covered surface of the battery cell to reduce uncontrolled heat conduction between the environment and the battery cell; A heat dissipation device is disposed on the hot surface of the TEC to conduct heat from the hot surface of the TEC to the environment; The temperature acquisition module includes multiple temperature sensors, which are respectively disposed on the surface of the battery cell, the cold side of the TEC, and the hot side of the TEC, and are used to acquire the battery cell temperature, the TEC cold side temperature, and the TEC hot side temperature, respectively. A thermal management controller is electrically connected to the temperature acquisition module and the TEC drive circuit. Based on the cell temperature, the TEC cold surface temperature and the TEC hot surface temperature, it outputs a PWM control signal to the TEC drive circuit through a temperature control strategy to adjust the TEC's operating mode and input power. The TEC drive circuit is electrically connected to the thermal management controller and the TEC, and is used to drive the TEC to work in low-temperature heating mode, normal standby mode or high-temperature cooling mode. The thermal insulation structure and the TEC form a synergistic thermal management structure.

[0019] In this invention, the cell temperature, TEC cold side temperature, and TEC hot side temperature of the power industry backup battery are acquired in real time through a temperature acquisition module. Based on the cell temperature and a preset temperature threshold, a thermal management controller determines the TEC's operating mode, which includes a low-temperature heating mode, a normal standby mode, and a high-temperature cooling mode. According to the operating mode, the thermal management controller controls the power supply direction of the TEC drive circuit to drive the TEC to operate in the specified mode. Based on the deviation between the cell temperature and a preset target temperature, the thermal management controller controls the PWM duty cycle of the TEC drive circuit to adjust the TEC's input power until the cell temperature reaches the preset target temperature. Based on the cell temperature, the TEC cold side temperature, and the TEC hot side temperature, a cold start strategy, a low SOC protection strategy, a TEC thermoelectric power recovery strategy, a pre-compensation strategy, and a control parameter configuration strategy are employed to perform thermal management on the power industry backup battery. This invention enables backup power supplies for the power industry to operate safely and reliably in extreme ambient temperatures ranging from -40℃ to 70℃ through cold start strategy, low SOC protection strategy, TEC thermoelectric power generation recovery strategy, pre-compensation strategy, and control parameter configuration strategy, and the same hardware platform is compatible with multiple cell chemical systems. Attached Figure Description

[0020] Figure 1 This is a flowchart of a preferred embodiment of the wide-temperature-range thermal management method for backup batteries in the power industry according to the present invention; Figure 2 This is a schematic cross-sectional view of the wide-temperature-range thermal management system for backup batteries in the power industry according to the present invention. Figure 3 This is a schematic diagram showing the unfolded thermal insulation structure and TEC synergistic thermal management structure of the present invention; Figure 4 This is a flowchart of the thermal management state machine of the present invention; Figure 5 This is a timing diagram of the extreme low temperature cold start strategy of this invention; Figure 6This is a block diagram of the four-point NTC closed-loop PID control system of the present invention; Figure 7 This is a schematic diagram of the H-bridge drive circuit and TEC / TEG mode switching of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0022] Power distribution terminals, communication base stations, emergency power supplies for rail transit, and outdoor online monitoring equipment are critical devices deployed in large numbers in industrial infrastructure. They all rely on backup lithium batteries to maintain uninterrupted operation when mains power is interrupted. These devices are generally deployed in outdoor environments with temperatures ranging from -40°C to 70°C.

[0023] (1) Power distribution terminal: deployed in outdoor poles, ring network cabinets and other places, where the direct sunlight temperature can reach above 70℃, and the winter temperature in cold regions such as Northeast and Northwest can drop to -40℃. The backup battery needs to work for more than 10 years without replacement.

[0024] (2) Communication base stations: With the significant increase in 5G base station density, a large number of base station equipment are installed in outdoor cabinets, resulting in more stringent heat dissipation requirements; at the same time, in cold regions, batteries need to be insulated in winter to prevent capacity decay and power outages. Communication base stations have extremely high requirements for power supply reliability, and the performance of backup batteries directly affects the continuity of network services.

[0025] (3) Rail Transit: The backup power supply for equipment such as turnout control, signaling system, and platform emergency lighting in urban rail transit must meet the high reliability requirements of rail transit industry standards (TB / T series). The temperature inside the tunnel can reach above 50℃, and the temperature along the plateau railway can drop to below -40℃, which places high demands on the extreme temperature adaptability of battery thermal management.

[0026] (4) Online monitoring: Equipment such as power transmission line fault indicators, oil and gas pipeline leakage monitoring, and environmental meteorological monitoring are deployed in the field all year round, making replacement and maintenance difficult. The batteries are required to maintain a high capacity under extreme temperatures and have a lifespan of no less than 5 years.

[0027] Currently, commonly used cell chemistry systems in industrial backup power supplies include lithium iron phosphate (LFP), ternary lithium (NCM / NCA), lithium titanate (LTO), and sodium-ion batteries. These different chemistry systems have varying operating temperature ranges: LFP batteries have a charging temperature range of 0~45℃ and a discharging temperature range of -20~60℃; ternary lithium batteries have a charging temperature range of 0~45℃ and a discharging temperature range of -10~55℃; lithium titanate batteries have a discharging temperature range of -30~60℃, exhibiting better low-temperature performance than LFP; and sodium-ion batteries have a charging temperature range of -10~45℃ and a discharging temperature range of -30~55℃, offering good low-temperature performance and cost advantages. At high temperatures (>45℃), the internal resistance of various lithium-ion cells increases, side reactions intensify, and lifespan declines sharply, posing a risk of thermal runaway. At low temperatures (<0℃), the lithium-ion migration rate decreases, and lithium dendrite precipitation during charging can easily occur, leading to internal short circuits and a significant decrease in discharge capacity. Although lithium titanate and sodium-ion batteries have better low-temperature performance, they still suffer from capacity decay and limited charging at extreme low temperatures (-40°C), requiring thermal management intervention.

[0028] Existing battery thermal management solutions are mainly designed for new energy vehicles and large-scale energy storage power stations, using liquid cooling, air cooling, or phase change materials (PCM). However, backup batteries in the above-mentioned industrial infrastructure scenarios have the following special characteristics: (1) small power level (usually 12V / 6Ah~48V / 40Ah, with various series and parallel topologies), which cannot bear the power consumption and volume of liquid cooling systems; (2) limited installation space, usually the standard battery compartment size; (3) high maintenance requirements, especially in communication base stations, rail transit, and online monitoring scenarios, where leakage risk is not allowed; (4) need to meet the dual requirements of high-temperature heat dissipation and low-temperature heating at the same time; (5) different cell chemical systems have different temperature management requirements, and the system needs to have chemical system self-adaptation capabilities.

[0029] Thermoelectric cooling chips (TECs), based on the Peltier effect, can achieve bidirectional cooling / heating functions by changing the direction of current. They offer advantages such as no moving parts, compact size, high reliability, and precise temperature control, making them ideal for the aforementioned industrial scenarios. However, existing TEC-based battery thermal management solutions have the following shortcomings: (1) Without insulation structure, ambient heat can be uncontrollably introduced into the battery cell from the non-TEC covered area, resulting in low TEC cooling efficiency, especially at extreme high temperature of 70℃, the cooling load far exceeds the TEC capacity; (2) The problem of TEC cold start at extreme low temperature of -40℃ was not considered. The large temperature difference established inside the TEC in an instant will generate thermal stress, which will cause the solder joint to crack and fail. (3) The temperature acquisition point is singular (only the battery temperature is collected), which cannot detect the working status of TEC and abnormalities such as reversed cooling direction cannot be detected in time; (4) Lack of low SOC protection mechanism for industrial backup power scenarios; TEC heating may deplete the remaining battery power and cause the system to lose power. (5) The temperature management requirements of different cell chemical systems (lithium iron phosphate, ternary lithium, lithium titanate, sodium ion battery, etc.) are not considered. Existing solutions are usually designed for a single chemical system and cannot be compatible with multiple cell chemical systems through a unified hardware platform. (6) The existing TEC scheme only uses TEC as a power-consuming temperature control element and does not consider using the natural temperature difference formed by the insulation structure in the environment of large day-night temperature difference to recover thermal power generation, resulting in low energy utilization rate; (7) The existing scheme lacks feedforward control based on ambient temperature prediction and only performs feedback control based on the current cell temperature, which cannot eliminate high-temperature overshoot and low-temperature lag caused by thermal inertia.

[0030] To address the aforementioned technical problems, this invention provides a wide-temperature-range thermal management method for backup batteries in the power industry. The method involves acquiring the cell temperature, TEC cold-side temperature, and TEC hot-side temperature of the backup battery in real time via a temperature acquisition module. Based on the cell temperature and a preset temperature threshold, a thermal management controller determines the operating mode of the TEC, which includes a low-temperature heating mode, a normal standby mode, and a high-temperature cooling mode. According to the operating mode, the thermal management controller controls the power supply direction of the TEC drive circuit to drive the TEC to operate according to the specified mode. Based on the deviation between the cell temperature and a preset target temperature, the thermal management controller controls the PWM duty cycle of the TEC drive circuit to adjust the input power of the TEC until the cell temperature reaches the preset target temperature. Based on the cell temperature, the TEC cold-side temperature, and the TEC hot-side temperature, a cold-start strategy, a low-SOC protection strategy, a TEC thermoelectric power recovery strategy, a pre-compensation strategy, and a control parameter configuration strategy are employed to perform thermal management on the backup battery. This invention enables backup power supplies for the power industry to operate safely and reliably in extreme ambient temperatures ranging from -40℃ to 70℃ through cold start strategy, low SOC protection strategy, TEC thermoelectric power generation recovery strategy, pre-compensation strategy, and control parameter configuration strategy, and the same hardware platform is compatible with multiple cell chemical systems.

[0031] The application content will be further explained below with reference to the accompanying drawings and the description of the embodiments.

[0032] A preferred embodiment of the wide-temperature-range thermal management method for backup batteries in the power industry according to the present invention is as follows: Figure 1 As shown, it specifically includes: S1. The temperature acquisition module acquires the cell temperature, TEC cold surface temperature, and TEC hot surface temperature of the backup battery in the power industry in real time.

[0033] Specifically, the temperature sensors of the temperature acquisition module are arranged as follows: the first and second temperature sensors are respectively arranged on the surface of the cells at different locations in the battery module (i.e., backup batteries for the power industry) to detect the temperature distribution and temperature difference of the cells; the third temperature sensor is attached to the cold side of the TEC to detect the temperature of the cold side of the TEC; the fourth temperature sensor is attached to the heat dissipation device on the hot side of the TEC to monitor the temperature of the hot side of the TEC; the temperature sensors are selected from one of the following: NTC (Negative Temperature Coefficient) thermistors, PT100 / PT1000 platinum resistance thermometers, or digital temperature sensors.

[0034] S2. Based on the cell temperature and the preset temperature threshold, the thermal management controller determines the operating mode of the TEC, wherein the operating mode includes low temperature heating mode, normal standby mode and high temperature cooling mode.

[0035] In one implementation of this embodiment, the preset temperature threshold includes a first preset temperature threshold and a second preset temperature threshold, wherein the first preset temperature threshold is less than the second preset temperature threshold; The step of determining the operating mode of the TEC (Thermal Control Controller) based on the cell temperature and a preset temperature threshold specifically includes: The operating mode of the TEC is determined by comparing the cell temperature with the first preset temperature threshold and the second preset temperature threshold using a thermal management controller. If the cell temperature is lower than the first preset temperature threshold, the TEC is determined to be in low-temperature heating mode. If the cell temperature is not less than the first preset temperature threshold and not greater than the second preset temperature threshold, the TEC is determined to be in normal standby mode. If the cell temperature is greater than the second preset temperature threshold, the TEC is determined to be in high-temperature cooling mode.

[0036] Specifically, based on the cell temperature, the operating mode of the TEC is determined through a temperature control strategy. The operating modes include low-temperature heating mode, normal standby mode, and high-temperature cooling mode.

[0037] S3. According to the operating mode, the power supply direction of the TEC drive circuit is controlled by the thermal management controller to drive the TEC to work according to the operating mode.

[0038] In one implementation of this embodiment, the step of controlling the power supply direction of the TEC drive circuit through a thermal management controller according to the operating mode, so as to drive the TEC to operate according to the operating mode, specifically includes: When the operating mode of the TEC is determined to be low-temperature heating mode, the power supply direction of the TEC drive circuit is controlled to the first power supply direction by the thermal management controller, so as to drive the TEC to be in low-temperature heating mode. The TEC transfers heat to the battery cell and reduces the heat loss of the battery cell to the environment through the heat insulation structure. When the operating mode of the TEC is determined to be normal standby mode, the thermal management controller controls the TEC drive circuit to stop supplying power, so that the TEC is in normal standby mode and the TEC stops working; When the operating mode of the TEC is determined to be high temperature cooling mode, the power supply direction of the TEC drive circuit is controlled to the second power supply direction by the thermal management controller, so as to drive the TEC to be in high temperature cooling mode. The TEC extracts heat from the battery cell and blocks ambient heat from entering the battery cell from the non-TEC covered surface through the heat insulation structure. The TEC is disposed on one side of the battery cell, and the heat insulation structure is disposed on the non-TEC covered side of the battery cell. The TEC and the heat insulation structure form a synergistic thermal management structure.

[0039] Specifically, in low-temperature heating mode, the uncontrolled heat loss from the battery cell to the environment is reduced in the presence of the insulation structure. Simultaneously, the TEC drive circuit supplies power to the TEC with the first polarity or switches to the heating TEC group, allowing the TEC to transfer heat to the battery cell. In high-temperature cooling mode, the path for ambient heat to enter the battery cell from the non-TEC-covered area is blocked in the presence of the insulation structure. Simultaneously, the TEC drive circuit supplies power to the TEC with the second polarity or switches to the cooling TEC group, allowing the TEC to extract heat from the battery cell. In normal standby mode, the TEC stops working. The insulation structure and the TEC cooling element (i.e., the TEC) form a synergistic thermal management structure: the area covered by the TEC cooling element constitutes a controlled heat conduction channel, and the area covered by the insulation structure constitutes a heat blocking channel. Together, they keep the main heat exchange path between the battery cell and the external environment under control.

[0040] S4. Based on the deviation between the cell temperature and the preset target temperature, the PWM (Pulse Width Modulation) duty cycle of the TEC drive circuit is controlled by the thermal management controller to adjust the input power of the TEC until the cell temperature reaches the preset target temperature.

[0041] Specifically, the thermal management controller calculates the PWM control signal based on the deviation between the cell temperature and the target temperature, and adjusts the TEC power output to bring the cell temperature closer to the target temperature. The control signal for the TEC drive circuit is driven by the PWM output of the thermal management controller, and the average power of the TEC is controlled by adjusting the duty cycle.

[0042] S5. Based on the cell temperature, the TEC cold surface temperature, and the TEC hot surface temperature, thermal management is performed on the power industry backup battery using a cold start strategy, a low SOC protection strategy, a TEC thermoelectric power generation recovery strategy, a pre-compensation strategy, and a control parameter configuration strategy.

[0043] In one implementation of this embodiment, when the cell temperature is below an extreme low temperature threshold, a cold start strategy is executed, the cold start strategy including: The TEC is preheated using a first preset low power ratio of its rated power as the heating power. When the first temperature difference between the hot surface temperature and the cold surface temperature of the TEC is lower than the thermal stress threshold, the heating power of the TEC is gradually increased to the rated power at a preset rate. When the first temperature difference is greater than the preset upper limit of temperature difference, the heating power of the TEC is paused; when the first temperature difference is less than the preset lower limit of temperature difference, the heating power of the TEC continues to be increased. During the execution of the cold start strategy, the battery management system locks the charging and discharging functions of the power industry backup battery. When the cell temperature is greater than the first preset unlocking temperature, the battery management system unlocks the charging function. When the cell temperature is greater than the second preset unlocking temperature, the battery management system unlocks the discharging function.

[0044] Specifically, when the cell temperature T_cell is below the extreme low temperature threshold, a cold start strategy is implemented: the TEC body is preheated for a first predetermined time at a first preset low power ratio of the TEC's rated power, so that the internal temperature difference of the TEC is lower than the thermal stress threshold; after preheating, the TEC heating power is gradually increased to the rated power at a preset rate to avoid the thermal stress caused by the instantaneous large temperature difference inside the TEC, which could lead to solder joint cracking; when the difference between the TEC hot surface temperature T_hot and the TEC cold surface temperature T_cold exceeds the preset upper limit of temperature difference, the power increase is paused, and the increase continues after the temperature difference drops back to the preset lower limit of temperature difference; during the cold start period, the BMS (Battery Management System) prohibits the charging and discharging operations of the battery module until the T_cell reaches the first preset unlocking temperature to unlock the charging function, and the T_cell reaches the second preset unlocking temperature to unlock the discharging function.

[0045] In one implementation of this embodiment, the wide-temperature-range thermal management method for backup batteries in the power industry further includes a hardware over-temperature protection strategy, which includes: When the temperature of the TEC hot surface exceeds the preset hot surface protection threshold, the power supply to the TEC is cut off by a hardware comparator. When the cell temperature exceeds a preset cell protection threshold, the charging and discharging circuit of the power industry backup battery is cut off by the battery management system, so that the power industry backup battery enters a thermal protection state.

[0046] Specifically, when the TEC hot surface temperature T_hot exceeds the preset hot surface protection threshold, the hardware comparator directly cuts off the TEC power supply without going through the software judgment of the thermal management controller; when the cell temperature T_cell exceeds the preset cell protection threshold, the BMS cuts off the charging and discharging circuit of the battery module and enters the thermal protection state.

[0047] In one implementation of this embodiment, the low SOC protection strategy includes: During the period when the TEC is in low-temperature heating mode, the SOC value of the power industry backup battery is monitored in real time by the thermal management controller; When the SOC value is lower than the first preset SOC threshold, the heating power of the TEC is reduced to a second preset low power ratio of the rated power; When the SOC value is lower than the second preset SOC threshold, the heating function of the TEC is turned off until the external charging is restored, at which point the heating function of the TEC is turned on again.

[0048] Specifically, during TEC heating operation, the thermal management controller monitors the SOC value of the battery module in real time. When the SOC is lower than the first preset SOC threshold S1, the TEC heating power is reduced to a second preset low power ratio of the rated power. When the SOC is lower than the second preset SOC threshold S2, the TEC heating function is turned off, and only the BMS operates at minimum power consumption, waiting for external charging to resume. The S1 and S2 thresholds are adjusted according to the cell chemistry, module capacity, and application scenario through BMS configuration parameters. When the battery module SOC (state of charge, representing the remaining charge) is lower than the preset low SOC threshold and the T_cell is lower than the preset low temperature threshold, the thermal management controller limits the TEC heating power to no more than a preset ratio of the rated power to prevent the TEC heating from depleting the remaining battery charge and causing the system to lose power.

[0049] In one implementation of this embodiment, the TEC (Thermoelectric Generating Recovery) strategy includes: When the ambient temperature is higher than the cell temperature and the second temperature difference between the ambient temperature and the cell temperature exceeds the preset TEG start-up threshold, the TEC is switched to thermoelectric power generation mode by the thermal management controller. In thermoelectric power generation mode, an electromotive force is generated by the temperature difference gradient formed between the heat insulation structure and the TEC. The TEC, as a thermoelectric power generation device, converts ambient heat into electrical energy. After being regulated by a DC-DC converter circuit, the electrical energy is used to additionally charge the power industry backup battery or maintain the battery management system at minimum power consumption. Based on the first temperature difference and the ambient temperature, query the pre-stored TEG output characteristic curve, and estimate the current recoverable power based on the TEG output characteristic curve. When the current recoverable power is greater than a preset ratio of the input power required by the TEC to offset the same heat flow in high-temperature cooling mode, the TEC preferentially operates in thermoelectric power generation mode. The TEG output characteristic curve is dynamically updated according to the TEC model, aging state, and cell chemical system identification.

[0050] Specifically, the switching between TEC / TEG modes (TEC mode refers to thermoelectric cooling / heating mode, and TEG mode refers to thermoelectric power generation mode) is achieved by an H-bridge drive circuit in conjunction with a mode switching switch, or by an independent bidirectional DC-DC energy recovery circuit.

[0051] In one implementation of this embodiment, the pre-compensation strategy includes: Receive ambient temperature prediction data through the BMS communication interface; When the predicted ambient temperature data within a preset time period is less than the first preset temperature threshold or greater than the second preset temperature threshold, and the cell temperature is not less than the first preset temperature threshold and not greater than the second preset temperature threshold, the thermal management controller controls the TEC drive circuit to drive the TEC to enter the low-temperature heating mode or high-temperature cooling mode in advance.

[0052] Specifically, the system receives ambient temperature prediction data via an industrial communication interface. When it predicts that the ambient temperature will reach the cooling start-up threshold (i.e., the second preset temperature threshold) or the heating start-up threshold (i.e., the first preset temperature threshold) within a preset time period, it initiates TEC cooling or TEC heating in advance, even before the current cell temperature has reached the corresponding threshold. The advance start-up time is dynamically corrected based on prediction errors and actual temperature feedback. The ambient temperature prediction data originates from a SCADA (Supervisory Control And Data Acquisition) system, a base station network management system, or an external meteorological service interface.

[0053] In one implementation of this embodiment, the wide-temperature-range thermal management method for backup batteries in the power industry further includes an adaptive optimization strategy, which includes: The adaptive COP optimizer built into the thermal management controller queries the pre-stored TEC characteristic parameter table based on the first temperature difference, the cell temperature, and the cell chemical system identifier. Obtain the target operating current or target PWM duty cycle that maximizes the instantaneous energy efficiency ratio (COP) of the TEC from the TEC characteristic parameter table; The thermal management controller controls the TEC drive circuit to operate at the target operating current or the target PWM duty cycle so that the instantaneous energy efficiency ratio (COP) of the TEC reaches its maximum value.

[0054] Specifically, the thermal management controller has a built-in TEC adaptive COP optimizer, which optimizes the real-time temperature difference between the hot and cold surfaces of the TEC. The system identifies the cell temperature and cell chemical system. It then queries a pre-stored TEC characteristic parameter table to select the operating current or PWM duty cycle that maximizes the TEC's instantaneous energy efficiency ratio (COP). COP is the ratio of the TEC's cooling or heating capacity to its input electrical power (i.e., input power). The TEC characteristic parameter table includes various... Voltage-current curves, cooling capacity-current curves, and COP-current curves under the given conditions.

[0055] In one implementation of this embodiment, the wide-temperature-range thermal management method for backup batteries in the power industry further includes an early warning strategy for thermal runaway and a TEC emergency suppression strategy, wherein the early warning strategy for thermal runaway and the TEC emergency suppression strategy includes: Based on the cell temperature, the TEC cold surface temperature and the TEC hot surface temperature, the cell temperature change rate, the first temperature difference change rate and the temperature gradient at different locations of the cell are calculated in real time. When the cell temperature change rate or the first temperature difference change rate is greater than the first preset warning threshold or the temperature gradient is greater than the second preset warning threshold, it is determined that there is an early risk of thermal runaway, and the TEC is switched to emergency suppression mode through the thermal management controller. In emergency suppression mode, the TEC actively cools the abnormal area of ​​the cell at maximum safe power, and disconnects the charging and discharging circuit of the power industry backup battery through the battery management system and reports an alarm.

[0056] Specifically, the system calculates the cell temperature change rate, the TEC hot and cold surface temperature difference change rate, and the temperature gradient at different locations within the cell assembly in real time. When any temperature change rate exceeds the first preset warning threshold or the temperature gradient exceeds the second preset warning threshold, it determines that there is an early risk of thermal runaway. The TEC emergency cooling mode is immediately activated to actively cool the abnormal area with maximum safe power. At the same time, the BMS cuts off the charging and discharging circuit of the battery module and reports an alarm.

[0057] In one implementation of this embodiment, the wide-temperature-range thermal management method for backup batteries in the power industry further includes a temperature control strategy, which includes: The real-time instantaneous energy efficiency ratio (COP) of the TEC is calculated based on the first temperature difference. When the real-time instantaneous energy efficiency ratio (COP) is less than a preset COP threshold, the input power of the TEC is reduced or the TEC is switched to passive cooling mode by the thermal management controller. When the first temperature difference is greater than the preset reversal determination threshold, it is determined that the cooling direction of the TEC is reversed, and the power supply to the TEC is cut off by the thermal management controller; A temperature dead zone is set with the preset target temperature as the center. When the cell temperature is within the temperature dead zone, the thermal management controller maintains the input power of the TEC at a constant level. A first temperature hysteresis and a second temperature hysteresis are set based on the first preset temperature threshold and the second preset temperature threshold, respectively, to prevent the TEC from frequently switching working modes at the first preset temperature threshold or the second preset temperature threshold. The temperature control strategy architecture includes state machine control or continuous control, and the temperature control strategy algorithm includes PID closed-loop control, fuzzy control, ON-OFF hysteresis control, or lookup table method.

[0058] Specifically, the temperature control strategy includes state machine control and / or continuous control. When state machine control is used, thermal management is divided into multiple states, and the temperature thresholds between each state are set according to the cell chemistry system and application scenario. When continuous control is used, the TEC power is continuously adjusted according to the deviation between the cell temperature and the target temperature, without dividing into discrete states. The specific implementation of the temperature control strategy is as follows: Target temperatures for both charging and discharging states are set, along with a temperature dead zone. When T_cell is within the dead zone, the TEC maintains its current power to prevent frequent switching and oscillation. The temperature control strategy outputs a PWM control signal, with the frequency and duty cycle adjustment range set according to the TEC model and system requirements. When the duty cycle is below a preset lower limit, the TEC is directly shut down to eliminate efficiency losses at low duty cycles. The temperature control strategy includes any one of PID (Proportional-Integral-Derivative) closed-loop control, fuzzy control, ON-OFF hysteresis control, or lookup table method. When using PID closed-loop control, an anti-saturation limit is set to prevent excessive accumulation of the integral term due to long-term large deviations during the low-temperature start-up phase. When the temperature difference between T_cold and T_cell exceeds a preset reversal threshold, the TEC cooling direction is determined to be reversed, and the TEC is immediately shut down with a fault alarm issued. A temperature hysteresis is set between adjacent states to prevent frequent switching at temperature boundaries. The hysteresis value is set to 1~5℃ based on the cell chemical system and application scenario.

[0059] In one implementation of this embodiment, the control parameter configuration strategy includes: Multiple sets of thermal management parameters corresponding to various cell chemical systems are pre-stored. Each set of thermal management parameters includes the first preset temperature threshold, the second preset temperature threshold, the extreme low temperature threshold, the first preset low power ratio, the thermal stress threshold, the preset rate, the preset upper limit of temperature difference, the preset lower limit of temperature difference, the first preset unlocking temperature, the second preset unlocking temperature, the preset hot surface protection threshold, the preset cell protection threshold, the first preset SOC threshold, the second preset low power ratio, the second preset SOC threshold, the preset TEG start-up threshold, the preset ratio, the preset future duration, the first preset warning threshold, the second preset warning threshold, the preset COP threshold, the preset reversal determination threshold, the first temperature hysteresis, and the second temperature hysteresis. Obtain the cell chemical system identifier corresponding to the backup battery for the power industry, and based on the cell chemical system identifier, call the target thermal management parameter group corresponding to the cell chemical system identifier from multiple pre-stored thermal management parameter groups; Thermal management of the power industry backup battery is performed through a thermal management controller based on the target thermal management parameter set. The battery cell chemistry system includes lithium iron phosphate batteries, ternary lithium batteries, lithium titanate batteries, and sodium-ion batteries. The thermal management parameter group supports online updates and configuration adjustments through the BMS communication interface.

[0060] Specifically, the system pre-stores thermal management parameter sets corresponding to various cell chemistry systems in the storage medium; reads the cell chemistry system identifier used by the current battery module; calls the corresponding thermal management parameter set based on the cell chemistry system identifier; determines the switching boundary of the thermal management mode based on the temperature threshold in the thermal management parameter set; adjusts the TEC power output based on the heating power ratio parameter; executes the extreme low temperature cold start process based on the cold start strategy parameter; and executes low SOC protection logic based on the SOC protection parameter. Different chemistry systems correspond to different thermal management parameter sets, enabling the same hardware platform to be compatible with multiple cell chemistry systems through software parameter configuration; the parameter sets support online updates and configuration adjustments via the BMS communication interface, allowing adaptation to new cell chemistry systems without hardware modifications.

[0061] Furthermore, based on the aforementioned wide-temperature-range thermal management method for backup batteries in the power industry, this invention also provides a wide-temperature-range thermal management system for backup batteries in the power industry. A preferred embodiment of the wide-temperature-range thermal management system for backup batteries in the power industry specifically includes: Backup batteries (i.e., battery modules) for the power industry are composed of cells connected in different series and parallel configurations. The cell shapes include three types: cylindrical, prismatic, and pouch. The series and parallel topologies include, but are not limited to, XS1P, XS2P, and XS3P, where X is the number of cells in series and P is the number of branches in parallel. The battery module is encapsulated in a shell, and the shell material is selected from one or more combinations of aluminum alloy, sheet metal, stainless steel, and engineering plastics. The TEC is disposed on the surface of the battery cell and is thermally coupled to the battery cell through a thermally conductive interface layer or a thermally conductive component or through direct contact. A thermal insulation structure (preferably aerogel felt or XPS extruded board) is disposed on the non-TEC covered surface of the battery cell (i.e., between the remaining surface of the TEC cooling chip and the outer casing) to reduce uncontrolled heat conduction between the environment and the battery cell; A heat dissipation device is disposed on the hot surface of the TEC to conduct heat from the hot surface of the TEC to the external environment; The temperature acquisition module includes multiple temperature sensors, which are respectively disposed on the surface of the battery cell, the cold side of the TEC, and the hot side of the TEC, and are used to acquire the battery cell temperature, the TEC cold side temperature, and the TEC hot side temperature, respectively. A thermal management controller is electrically connected to the temperature acquisition module and the TEC drive circuit. Based on the cell temperature, the TEC cold surface temperature and the TEC hot surface temperature, it outputs a PWM control signal to the TEC drive circuit through a temperature control strategy (preferably PID algorithm) to adjust the TEC's operating mode and input power. The TEC drive circuit (preferably an H-bridge drive circuit) is electrically connected to the thermal management controller and the TEC, and is used to drive the TEC to work in low-temperature heating mode, normal standby mode or high-temperature cooling mode; when it is necessary to achieve both cooling and heating modes at the same time, the TEC drive circuit achieves mode switching by switching the direction of the current flowing through the TEC. The heat insulation structure and the TEC form a synergistic thermal management structure. The area covered by the TEC cooling chip constitutes a controlled heat conduction channel, and the area covered by the heat insulation structure constitutes a heat blocking channel. Together, they keep the main heat exchange path between the battery cell and the external environment under control.

[0062] Specifically, the battery cells are selected from one or more of lithium iron phosphate (LFP) cells, ternary lithium (NCM / NCA) cells, lithium titanate (LTO) cells, and sodium-ion battery cells. The temperature management requirements of cells with different chemical systems are as follows: Lithium iron phosphate cells are suitable for power distribution terminals and communication base station scenarios, with a charging temperature range of 0~45℃ and a discharging temperature range of -20~60℃; ternary lithium cells are suitable for high energy density demand scenarios, with a charging temperature range of 0~45℃ and a discharging temperature range of -10~55℃; lithium titanate cells are suitable for extreme low temperature scenarios, with a discharging temperature range of -30~60℃; sodium-ion battery cells are suitable for low-cost scenarios, with a charging temperature range of -10~45℃ and a discharging temperature range of -30~55℃.

[0063] The insulation structure uses low thermal conductivity insulation materials or structures, including but not limited to aerogel felt, XPS extruded board, vacuum insulation board, polyurethane foam, rock wool, or air gap insulation layer, with a thermal conductivity of... The insulation structure, with a thickness of 3-8mm, covers the upper and lower surfaces of the battery module, as well as the side surfaces without TEC cooling elements. A 2-5mm air gap can be left between the outer side of the insulation structure and the outer shell to further reduce convective heat transfer. The shell material is selected based on the application scenario: aluminum alloy or sheet metal shells are preferred for power distribution terminals and communication base stations; stainless steel or aluminum alloy shells (meeting IP55 protection standards) are used for rail transit scenarios; and engineering plastic shells can be used for outdoor online monitoring scenarios (reducing weight and cost). The insulation structure functions in both cooling and heating modes: in cooling mode, it blocks ambient heat from entering the battery cell from the non-TEC covered surface, allowing ambient heat to enter the cell mainly through a controlled path from the hot to the cold surface of the TEC, thereby reducing the cooling load of the TEC; in heating mode, it reduces heat loss from the battery cell to the environment, improves TEC heating efficiency, and shortens the battery cell heating time. The insulation structure reduces the passive heat load of the battery cell by more than 40% at an ambient temperature of 70℃ and reduces the passive heat loss of the battery cell by more than 50% at an ambient temperature of -40℃.

[0064] The TEC (Thermal Design Temperature) cooling chip consists of 1 to 6 semiconductor cooling chips connected in parallel, each chip measuring approximately 40mm x 40mm, with a maximum cooling capacity of 20 to 100W per chip. The number of TEC chips is configured according to the thermal management power requirements of the battery module. These requirements are related to the total module capacity, cell chemistry, cell shape, and series / parallel topology. The baseline configuration for the number of TEC chips is as follows: 3 to 6 chips for high-voltage modules (nominal voltage ≥ 36V), 2 to 3 chips for medium-voltage modules (nominal voltage 12 to 36V), and... For standard modules (nominal voltage ≤12V), 1-2 TECs are configured. For modules using multiple parallel branches (P≥2), the number of TECs is configured by multiplying the base number of single parallel branches by a factor of 0.6-0.8 times the number of parallel branches P. The thermal coupling method between the TEC and the battery cell is adapted to the battery cell shape: cylindrical batteries achieve thermal coupling through a phase change thermal pad and a thermally conductive aluminum plate; square or pouch batteries achieve surface contact thermal coupling directly with the cold surface of the TEC through thermally conductive silicone grease or a phase change thermally conductive sheet, or through direct contact. In addition to TECs, other thermoelectric temperature control elements can also be used, such as other semiconductor thermoelectric elements based on the Peltier effect.

[0065] A thermal interface layer can be provided between the TEC and the battery cell, and between the TEC and the hot surface heat dissipation device. The thermal interface layer is selected according to the shape of the battery cell: for cylindrical battery cells, a phase change thermal pad is used to fill the arc gap; for square or pouch battery cells, thermal grease or a phase change thermal sheet is used to achieve surface contact; the phase change thermal pad or phase change thermal sheet undergoes a phase change at temperatures above 60°C, filling the micro gaps at the interface and reducing the interface thermal resistance; when the surface of the square battery cell is a flat metal surface, the cold surface of the TEC can also directly contact the surface of the battery cell to achieve thermal coupling, without the need for an additional thermal interface layer.

[0066] The hot surface heat dissipation device is selected from one or more of the following combinations: aluminum alloy extruded fins, sheet metal stamped fins, heat pipe radiators, vapor chambers (VC plates), forced air cooling radiators, or phase change heat dissipation devices; when heat dissipation fins are used, the fin height is 10~30mm and the fin spacing is 3~8mm; the hot surface heat dissipation device can be thermally connected to the outer shell or connected to an independent liquid cooling circulation system for heat dissipation.

[0067] The TEC drive circuit is implemented in one of the following ways: (1) H-bridge drive circuit: composed of two N-channel MOSFETs and two P-channel MOSFETs forming a full-bridge structure, and the direction of TEC current is changed by switching the MOSFET conduction combination; (2) Relay commutation circuit: the direction of TEC current is reversed by switching relay contacts; (3) Dual-group TEC switching circuit: two groups of TECs are set to fix the cooling and heating directions respectively, and the working TEC group is switched by a switch; (4) Bidirectional DC-DC converter: the polarity of TEC power supply is reversed by a bidirectional conversion circuit; (5) Unidirectional drive circuit: fixed direction drive is implemented only for TEC cooling mode or only for TEC heating mode. The control signal of the TEC drive circuit is driven by the PWM output of the thermal management controller, and the average power of TEC is controlled by adjusting the duty cycle. The power supply of the TEC drive circuit is taken from the battery module itself, and the battery bus voltage is converted into the TEC working voltage by the DC / DC step-down module; when the external mains power supply is on, the TEC drive circuit is given priority by the external AC / DC power supply and does not consume battery power.

[0068] The entire system is encapsulated within a standard backup battery compartment in a power distribution terminal, outdoor cabinet of a communication base station, rail transit equipment enclosure, or online monitoring equipment housing. The housing material is selected from one or more combinations of aluminum alloy, sheet metal, stainless steel, and engineering plastics, and is determined according to the application scenario. The thermal management controller is integrated on the BMS main control board, reusing the BMS's MCU (Microcontroller Unit) resources without adding an additional controller chip. The thermal management controller has an industrial communication interface, which can report information such as cell temperature, TEC operating status, and SOC to the power distribution network SCADA, base station network management system, turnout control system, or monitoring backend. The system consumes no more than 0.5W in normal standby mode, 40~120W in full cooling mode (depending on the module), and 24~70W in full heating mode (depending on the module).

[0069] The system is used in industrial backup power applications, including but not limited to distribution terminals (DTU, FTU, TTU), 5G / 4G communication base station cabinets, emergency power supplies for rail transit signals / turnouts, online monitoring equipment for power transmission lines / pipelines / environment, industrial UPS (Uninterruptible Power Supply), backup power for data centers, backup power for security monitoring equipment, and backup power for marine navigation marks. The battery cells in the system are selected from lithium iron phosphate, ternary lithium (NCM / NCA), lithium titanate (LTO), or sodium-ion batteries, and the appropriate battery cell chemistry system is selected according to the temperature environment and energy density requirements of the application scenario.

[0070] The beneficial effects of this invention are as follows: 1. The thermal insulation structure and TEC collaborative thermal management structure enable ambient heat to enter and exit the cell mainly through the controlled path of TEC, reducing passive heat load by more than 40% at high temperature of 70℃ and heat loss by more than 50% at low temperature of -40℃, significantly improving the effective cooling / heating efficiency of TEC.

[0071] 2. Extreme low temperature cold start strategy: Through TEC preheating and power gradual increase mechanism, thermal stress damage caused by instantaneous large temperature difference inside TEC is avoided, ensuring reliable start-up in -40℃ environment.

[0072] 3. Multi-point temperature closed-loop control not only monitors the cell temperature, but also the cold and hot surfaces of the TEC. It can calculate the COP value of the TEC in real time and detect abnormalities such as reverse cooling direction, thus achieving precise temperature control.

[0073] 4. The system is adaptable to various industrial backup power supply scenarios, including power distribution terminals (DTU / FTU / TTU), 5G / 4G communication base station cabinets, emergency power supplies for rail transit signals / turnouts, and online monitoring equipment for power transmission lines / pipelines / environment. The battery cell chemistry systems cover lithium iron phosphate (LFP), ternary lithium (NCM / NCA), lithium titanate (LTO), and sodium-ion batteries. The temperature management requirements of different chemistry systems are adaptively adjusted through BMS configuration parameters. It supports multiple series-parallel topologies such as XS1P, XS2P, and XS3P. For each scenario, the battery cell specifications, chemistry system, and series-parallel combinations can be flexibly selected according to capacity, voltage, and temperature environment requirements, maintaining unified thermal management control logic and reducing platform development costs. For multi-parallel branch modules, the number of TEC chips is determined using a configuration coefficient method to ensure thermal management power matching.

[0074] 5. Multi-cell shape adaptation and integrated compact design; the thermal management controller reuses the BMS MCU resources without adding an additional controller chip; the TEC drive circuit preferably uses an H-bridge scheme, but can also be implemented using relay commutation, dual TEC switching, bidirectional DC-DC converter, or unidirectional drive circuit; thermal coupling between the TEC and the cell is achieved through a thermal interface layer, thermal conductive components, or direct contact. The thermal interface layer is adapted according to the cell shape (phase change thermal pads are used for cylindrical cells, and thermal grease or phase change thermal sheets are used for square or soft-pack cells) to ensure good thermal coupling effect for all types of cells; the whole is encapsulated in a standard backup battery compartment, using an aluminum alloy, sheet metal, stainless steel, or engineering plastic shell, which is maintenance-free, has no risk of leakage, and meets the stringent reliability requirements of communication base stations and rail transit.

[0075] 6. Low SOC protection mechanism: When the battery has insufficient remaining power, it automatically limits the power of the TEC or turns off the heating function to prevent the TEC from depleting the battery power, which could cause the power distribution terminal, base station, rail transit equipment or online monitoring system to lose power and disconnect.

[0076] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the H-bridge drive circuit described in the following embodiments is a preferred implementation of the TEC drive circuit; the insulation layer is a preferred implementation of the heat insulation structure; the heat dissipation fins are a preferred implementation of the hot-surface heat dissipation device in the claims; the NTC temperature sensor is a preferred implementation of the temperature sensor in the claims; the PID algorithm is a preferred implementation of the temperature control strategy in the claims; the thermally conductive interface layer is a preferred implementation of the thermally conductive interface layer, thermally conductive component, or direct contact in the claims; and the TEC cooling chip is a specific embodiment of a thermoelectric temperature control element. The temperature control strategy encompasses two implementation methods: state machine control divides thermal management into discrete states, while continuous control continuously adjusts the TEC power output based on temperature deviation without dividing into discrete states. At least one surface of the battery module is near any one or more of the side, top, and bottom surfaces of the battery module. Those skilled in the art will understand that the above preferred solutions can be replaced by other equivalent implementations without departing from the concept of the present invention.

[0077] Example 1: 48V 38Ah power distribution terminal backup battery module.

[0078] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment takes a 48V 38Ah lithium iron phosphate battery module as an example. This module is used as a backup power supply for distribution automation terminals (DTU / FTU / TTU), installed in outdoor pole-mounted switch boxes or ring main units, with an ambient temperature range of -40℃ to 70℃, and is required to operate maintenance-free for more than 10 years. The battery cells use cylindrical 40Ah large-cell lithium iron phosphate cells, which have advantages such as large heat dissipation area, low internal resistance, and good consistency.

[0079] 1. System Structure like Figure 2 As shown, the wide temperature range thermal management system of this embodiment includes the following components: Aluminum alloy casing (i.e., metal casing): Made of 6063 aluminum alloy by extrusion, with a wall thickness of 2mm, serving as the overall structural carrier of the system and the external heat dissipation interface. 15 cylindrical battery cells are arranged along the length and fixed inside the casing by a cell bracket.

[0080] TEC thermoelectric cooler array (i.e., TEC thermoelectric cooler): composed of 6 TEC1-12710 type semiconductor coolers connected in parallel, each measuring 40mm×40mm×3.8mm, with a maximum cooling capacity of 72W / piece and a maximum temperature difference of... Six TECs are arranged at equal intervals along the long side of the battery module, with the cold side of the TEC facing the cell side and the hot side facing the casing side. The curved surface of the cylindrical cell achieves surface contact thermal coupling with the cold side of the TEC through a thermally conductive aluminum plate and a phase change thermal pad.

[0081] Thermally conductive aluminum plate: Made of 6061 aluminum alloy, 3mm thick, covering all 6 TEC cold surfaces, evenly transferring the cold / heat energy from the TEC cold surfaces to the sides of the cell. A 0.5mm thick phase change thermal pad (Bergquist GP3000, thermal conductivity 3W / (m·K)) is placed between the thermally conductive aluminum plate and the cylindrical cell to fill the arc-shaped gap and reduce interfacial thermal resistance. The phase change thermal pad ensures good thermal contact between the arc surface of the cylindrical cell and the flat surface of the thermally conductive aluminum plate, a crucial design consideration when using cylindrical cells.

[0082] Insulation layer (i.e., heat insulation layer): 5mm thick aerogel felt (thermal conductivity...) The insulation layer covers the upper and lower surfaces of the battery module, as well as the other long side and two short sides without a TEC (Thermal Design Temperature) zone. A 3mm air gap is left between the outer side of the insulation layer and the aluminum alloy casing to further reduce convective heat transfer. The function of the insulation layer is to ensure that all heat exchange paths between the battery cell and the external environment can only pass through the TEC zone, forming a controlled heat conduction channel.

[0083] Heat dissipation fins: Located on the outer side of the aluminum alloy casing on the hot side of the TEC, these are extruded aluminum alloy fins, 20mm high, 4mm spaced, with a total area of ​​approximately 480cm². The heat dissipation fins are integrated with the casing, utilizing the natural ventilation of the power distribution terminal for heat dissipation.

[0084] Temperature acquisition module: includes 4 NTC 10kΩ thermistors (accuracy ±0.5℃, temperature range -50~150℃), which are respectively arranged on the surface of the cell where NTC1 and NTC3 are located at different positions (to detect the temperature distribution of the cell), NTC2 is attached to the thermally conductive aluminum plate (to detect the temperature of the cold side of the TEC), and NTC4 is attached to the root of the heat sink fins (to detect the temperature of the hot side of the TEC).

[0085] Thermal Management Controller: Integrated into the BMS main control board, it reuses STM32G031 MCU resources and runs a PID temperature control algorithm. Based on the temperature data from 4 NTC channels, the controller calculates the average cell temperature, cell temperature difference, TEC hot and cold surface temperature difference, and real-time COP value, and outputs a PWM signal to the H-bridge drive circuit.

[0086] H-bridge driver circuit: Utilizing a full-bridge structure composed of two N-channel MOSFETs and two P-channel MOSFETs, it receives a 12V input (provided by a 48V-to-12V DC / DC step-down module) and has a maximum output current of 60A. Switching between cooling and heating modes is achieved by changing the direction of the TEC current through switching the MOSFET conduction combination. The PWM frequency is 20kHz, with a duty cycle adjustment range of 10%~100%.

[0087] 2. Working principle of the insulation layer + TEC synergistic thermal management structure like Figure 3 As shown, the core innovation of this invention lies in the synergistic thermal management structure formed by the insulation layer and the TEC cooling chip array.

[0088] In high-temperature cooling mode (ambient temperature 70°C): In traditional solutions, ambient heat is transferred from the entire surface of the battery module to the cell, resulting in high heat flux density and low TEC cooling efficiency. In this invention, the insulation layer blocks ambient heat from the upper surface, lower surface, and three sides, allowing ambient heat to be transferred to the cell only through a controlled path from the TEC hot side to the TEC cold side. Calculations show that the insulation layer reduces the passive heat load at 70°C from approximately 120W to approximately 50W (a 58% reduction), and reduces the total TEC input power, which requires 85W of cooling, from approximately 170W to approximately 115W.

[0089] In low-temperature heating mode (ambient temperature -40℃): the insulation layer reduces heat loss from the battery cell to the -40℃ environment, allowing the TEC heating power to be used more to raise the battery cell temperature rather than compensate for heat loss. Calculations show that the insulation layer reduces heat loss at -40℃ from approximately 80W to approximately 35W (a 56% reduction), shortening the time for the battery cell to heat up from -40℃ to 0℃ from approximately 55 minutes to approximately 32 minutes.

[0090] 3. Thermal management state machine like Figure 4 As shown in Table 1, the thermal management controller divides thermal management into six states based on the cell temperature T_cell.

[0091] Table 1: Details of the six states of thermal management

[0092] A 2-3°C temperature hysteresis is set between adjacent states to prevent frequent switching at temperature boundaries. For example, the temperature threshold for switching from state 4 to state 3 is 40°C, and the temperature threshold for switching from state 3 to state 4 is 45°C, with a hysteresis of 5°C. When T_cell > 70°C, the BMS cuts off the charging and discharging circuit and enters thermal protection mode; when the TEC hot surface temperature T_hot > 85°C, the hardware over-temperature protection circuit directly cuts off the TEC power supply. Here, T_env represents the ambient temperature. This indicates the preset TEG startup threshold. It should be noted that... Figure 4 In this context, T refers to the cell temperature, the same as T_cell.

[0093] 4. Extreme Low Temperature Cold Start Strategy like Figure 5 As shown, when the cell temperature T_cell < -30℃, a cold start strategy is executed: Phase 1 (t0~t1, approximately 15~30 minutes): Preheat the TEC body at 10% of its rated power. Because a temperature gradient exists inside the TEC at extremely low temperatures, starting it at full power directly would instantly create a temperature difference exceeding 60°C inside the TEC, and the resulting thermal stress could cause the solder joints inside the TEC to crack. The preheating phase allows the internal temperature difference to gradually build up, avoiding thermal shock.

[0094] Phase Two (t1~t2, approximately 30~60 minutes): Gradually increase the TEC heating power at a rate of 2%~5% per second until the rated power is reached. During this increase, continuously monitor the temperature difference between the cold and hot sides of the TEC. ,when The power increase is paused temporarily, and it is resumed after the temperature difference drops below 50°C.

[0095] Phase 3 (after t2): The TEC continues to heat at its rated power until... Then it switches to state 2 (low-temperature heating), where the PID algorithm takes over power regulation. At this time, the BMS unlocks the charging function. (Rechargeable) Then unlock the discharge function.

[0096] 5. Four-point NTC closed-loop PID control like Figure 6 As shown, this invention employs a four-point NTC temperature acquisition system to form a closed-loop PID control system: NTC1 and NTC3: Collect cell temperature, take the average value as the feedback quantity T_cell_avg for PID control, and take the difference as the cell temperature difference. The monitoring volume. When If the temperature inside the module is uneven, the TEC power can be appropriately reduced to make the temperature more uniform.

[0097] NTC2: Collects the TEC cold surface temperature T_cold to calculate the real-time cooling / heating effect of the TEC. In cooling mode, T_cold should be lower than T_cell_avg; in heating mode, T_cold should be higher than T_cell_avg. If T_cold > T_cell_avg + 2°C during cooling, the cooling direction is determined to be reversed, the TEC is immediately shut down, and a fault alarm is issued.

[0098] NTC4: Collects the TEC hot-side temperature T_hot to monitor the TEC's heat dissipation status and help determine if a low COP is caused by insufficient heat dissipation. In cooling mode, COP = Qc / P_in, where Qc = K·(T_cell_avg - T_cold) is the estimated cooling capacity, K is the thermal conductivity, P_in = V_tec × I_tec is the TEC input power, V_tec is the TEC operating voltage, and I_tec is the TEC operating current. When COP < 0.3, it indicates that the TEC's operating efficiency is extremely low (usually accompanied by an excessively high T_hot, i.e., insufficient heat dissipation from the hot side), and the TEC power should be reduced or switched to passive cooling mode to save energy.

[0099] The parameters of the PID algorithm are as follows: target temperature in charging state 25℃, target temperature in discharging state 35℃, temperature dead zone ±2℃. When T_cell_avg is within the dead zone, TEC maintains the current power unchanged. The PID output PWM duty cycle has a frequency of 20kHz and a duty cycle range of 10%~100%. An anti-saturation limit is set for the integral term to prevent excessive accumulation of the integral term due to long-term large deviations during the low-temperature start-up phase.

[0100] 6. Low SOC protection mechanism During TEC heating operation (State 1 and State 2), the thermal management controller monitors the SOC value of the battery module in real time: When SOC < 20%, the TEC heating power is limited to no more than 50% of the rated power; When SOC < 10%, the TEC heating function is turned off, and only the BMS operates at minimum power consumption, waiting for external charging to restore. The aforementioned SOC threshold can be adjusted through BMS configuration parameters.

[0101] This protection mechanism prevents the TEC from depleting the remaining battery power due to prolonged heating in low-temperature environments, thus avoiding power loss and disconnection of the power distribution terminal due to the depletion of the backup battery.

[0102] 7. H-bridge drive circuit like Figure 7 As shown, the H-bridge drive circuit consists of a full-bridge structure composed of two N-channel MOSFETs and two P-channel MOSFETs (Q1~Q4). The TEC cooling chip array is connected between the midpoints A and B of the bridge arm.

[0103] Cooling mode: Q1 and Q4 are turned on, current flows from A to B, the cold side of the TEC absorbs heat towards the cell side, and the hot side releases heat towards the heat dissipation fin side.

[0104] Heating mode: Q2 and Q3 are turned on, current flows from B to A, the cold and hot sides of the TEC switch functions, the heat generated by the original cold side is transferred to the cell side to achieve the heating function.

[0105] The MOSFET gate is driven by the PWM output of the thermal management controller, which controls the average power of the TEC by adjusting the duty cycle. The PWM frequency is 20kHz, which is higher than the frequency audible to the human ear to avoid noise.

[0106] 8. The TEC / TEG bidirectional energy conversion function can convert natural temperature differences into electrical energy in environments with large day-night temperature variations. Actual measurements show that the 48V 38Ah lithium iron phosphate module can generate 80~150Wh of electricity per day in TEG mode under summer day-night temperature differences of up to 40℃, equivalent to 2%~4% of the total battery module capacity. This effectively extends the power supply time of backup power supplies such as power distribution terminals and communication base stations after mains power outages.

[0107] 9. Predictive pre-compensation for ambient temperature reduces cell temperature fluctuation by more than 60%, reduces TEC start-stop frequency and energy consumption, and avoids high-temperature overshoot or low-temperature lag caused by thermal inertia. It is particularly suitable for communication base stations and outdoor online monitoring equipment.

[0108] 10. Adaptive COP optimization improves the overall system energy efficiency ratio by 25%~40%, reduces TEC power consumption under the same thermal management effect, and reduces the impact on battery backup time.

[0109] 11. Early warning of thermal runaway and emergency suppression of TEC provide an additional active safety protection layer for industrial backup power supplies. Active cooling is initiated in the early stage of thermal runaway, extending the safety response window and improving the reliability of power distribution terminals and rail transit equipment.

[0110] Example 2: 48V20Ah communication base station backup battery module.

[0111] This embodiment uses a 48V 20Ah lithium iron phosphate battery module as an example, applied to the backup power supply of outdoor cabinets for 5G / 4G communication base stations. The internal temperature of communication base station cabinets can reach 55~65℃ in summer and drop to -30℃ in winter in extremely cold regions, and the power supply reliability requirements for base stations are extremely high (power outages are not allowed). The battery cells adopt a cylindrical 20Ah large single-cell structure (Φ46mm×140mm, 15S1P).

[0112] The specific requirements for communication base station scenarios are as follows: (1) High temperature priority: The temperature inside the base station cabinet is high in summer, and the cooling demand is greater than the low temperature heating demand. In this embodiment, the high temperature warning threshold is lowered from 45℃ to 40℃, and the TEC cooling is started in advance to prevent the battery cells from being in a high temperature environment above 45℃ for a long time and extend the cycle life.

[0113] (2) Power saving mode: When the communication base station is powered by mains power, the TEC drive circuit is powered by AC / DC mains power and does not consume battery power, so the TEC can maintain high power operation. After the mains power is interrupted and switched to battery power, the TEC power is limited to 50% of the rated power to ensure the power supply time of communication equipment.

[0114] (3) Communication interface: The thermal management controller reports data such as battery temperature, TEC operating status, and SOC to the base station network management system via RS485 / Modbus protocol, which facilitates remote monitoring and early warning.

[0115] The H-bridge drive circuit has a maximum output current of 30A, powered by a 48V to 12V DC / DC step-down module. The overall system cost and size are lower than in Example 1, making it suitable for large-scale mass deployment. The internal resistance of the cylindrical 20Ah cell is slightly higher than that of the 40Ah cell (≤20mΩ / cell), but still much lower than that of the prismatic cell of the same capacity, and does not affect the TEC thermal management effect.

[0116] Example 3: 24V 20Ah rail transit emergency power supply module.

[0117] This embodiment uses a 24V 20Ah lithium iron phosphate battery module as an example, applied as a backup power source for turnout control systems, signaling equipment, or platform emergency lighting in urban rail transit. Rail transit has extremely high requirements for power supply reliability, needing to meet the technical requirements of industry standards such as TB / T3074. The battery cells use cylindrical 20Ah lithium iron phosphate cells (8S1P), with a series voltage of 24V (nominal 25.6V), meeting low-voltage safety requirements and compatible with the standard DC power supply interface of the turnout controller.

[0118] The specific requirements for rail transit scenarios are as follows: (1) Vibration and shock protection: When the train passes by, there will be obvious vibration. Rubber damping pads are added to the battery cell bracket (meeting the vibration requirements of EN 50155 Cat.1). The TEC cooling chip and the heat-conducting aluminum plate are fixed with elastic clamping to prevent vibration from increasing the interface thermal resistance or causing the TEC to fall off.

[0119] (2) High-temperature cooling requirements in tunnels: Summer temperatures in urban subway tunnels can reach 50-55℃, much higher than at ground level. This embodiment lowers the high-temperature active cooling trigger threshold to 50℃, ensuring that the backup batteries for important equipment such as turnout control always operate within a safe temperature range. The three TEC chips have a maximum cooling capacity of 150W, which can maintain the cell temperature below 45℃ at a tunnel temperature of 55℃.

[0120] (3) Low temperature heating requirements of plateau lines: The winter temperature of plateau / cold lines such as Qinghai-Tibet Railway and Chengdu-Kunming Railway can drop to below -40℃. The extreme low temperature cold start strategy of this invention can effectively solve the reliable start problem of TEC at -40℃. The heating power of 3 TECs is about 60W, and the time required for the battery cell to heat up from -40℃ to 0℃ is about 40~55 minutes.

[0121] (4) High-reliability communication interface: The thermal management controller connects information such as battery temperature, TEC status, SOC, and fault alarms to the SCADA system or turnout control system via RS485 / Modbus or CAN (Controller Area Network) bus, supports remote real-time monitoring, and meets the requirements of the rail transit industry for equipment monitorability.

[0122] (5) Dual over-temperature protection: The hardware comparator over-temperature protection (T_hot>85℃ cuts off TEC power supply) and the BMS software over-temperature protection (T_cell>70℃ cuts off charging and discharging circuit) both meet the requirements of TB / T 3074 for battery pack protection functions.

[0123] Example 4: Backup battery module for 24V 7Ah outdoor online monitoring equipment.

[0124] The battery module in this embodiment is 24V 7Ah (8S1P, 8 cylindrical lithium iron phosphate cells of 3.2V / 7Ah), suitable as a backup power source for outdoor online monitoring equipment such as power transmission line fault indicators, oil and gas pipeline leak detection, and environmental meteorological monitoring. These devices are installed in the field and have long maintenance cycles (typically every 2-3 years), requiring the battery to maintain high capacity even at extreme temperatures (-40℃ to 70℃) and a lifespan of no less than 5 years.

[0125] Since the module volume and heat capacity are significantly smaller than those in Examples 1-3, this example uses two TEC1-12706 type semiconductor cooling chips (each with a maximum cooling capacity of 50W), attached to the long side of the battery module. The insulation layer is 4mm thick aerogel felt, and the heat dissipation fin area is 200... The fin height is 15mm. The maximum output current of the H-bridge drive circuit is 15A, powered by a 24V to 12V DC / DC step-down module.

[0126] The control logic of the thermal management controller is the same as in Example 1, but due to the smaller heat capacity of the module (the total weight of 8 7Ah cells is approximately 2.4kg, and the heat capacity is approximately 1.2kJ / K), the temperature response speed is faster. At -40℃, the heating power of the two TECs is approximately 24W, and it takes approximately 45-60 minutes for the cells to heat up from -40℃ to 0℃. At 70℃, the cooling power of the two TECs is approximately 40W, which can maintain the cell temperature below 50℃.

[0127] The specific requirements for online monitoring equipment scenarios are as follows: (1) Ultra-low power standby: The daily power consumption of the monitoring equipment is extremely small. The power consumption of TEC in normal standby state (state 3) does not exceed 0.3W (NTC sampling only), which maximizes the battery standby time; (2) Solar Coordination: Monitoring equipment is usually equipped with small photovoltaic panels, which are powered by photovoltaic and battery in combination when the mains power is interrupted. The thermal management controller has photovoltaic input priority logic: when the photovoltaic output power is sufficient, the TEC drive is directly powered by photovoltaic; when the photovoltaic is insufficient, the TEC draws power from the battery and prioritizes reducing the TEC power to extend the monitoring equipment's battery life.

[0128] (3) Low SOC protection threshold adjustment: When SOC < 25%, limit TEC heating power to 50%; when SOC < 15%, turn off TEC heating function to adapt to the energy management needs of smaller capacity battery modules.

[0129] Example 5: 12V 24Ah power distribution automation / intelligent switch backup battery module.

[0130] This embodiment uses a 12V 24Ah lithium iron phosphate battery module as an example, applied to the backup power supply of equipment such as integrated primary and secondary intelligent switches, reclosers, and sectionalizers in medium and low voltage power distribution automation, as well as 12V DC power supply systems such as small backup power for communication base stations, street light controllers, and smart meter boxes. 12V systems are widely used in end-point equipment of power distribution networks, characterized by small size, large quantity, and high maintenance difficulty. The battery cells use cylindrical lithium iron phosphate cells (4S1P, 3.2V×4=12.8V), with a single-cell capacity of 24Ah (IFR32700 type, Φ32mm×70mm).

[0131] The thermal management characteristics of a 12V system are as follows: (1) Single-chip TEC power supply direct drive: The bus voltage of the 12V module is the same as the TEC working voltage (12V). The TEC drive circuit does not need an additional DC / DC step-down module. It directly draws power from the battery bus to drive the TEC through the H-bridge, which reduces the number of power conversion stages, resulting in higher system efficiency and lower cost.

[0132] (2) Small heat capacity and fast response: The total heat capacity of the four 24Ah cells is about 0.8kJ / K, which is much smaller than that of a 48V module. One TEC heating power of about 12W can heat the cell from -40℃ to 0℃ in about 35~50 minutes. At a high temperature of 70℃, one TEC cooling power of about 30W can keep the cell temperature below 50℃.

[0133] (3) Extremely low power consumption design requirements: The 12V backup battery capacity is relatively small (12V×24Ah=288Wh), and the power consumption of TEC has a more significant impact on the overall battery life. The maximum power consumption of TEC is about 12W (12V×1A), accounting for about 4.2% of the battery capacity. In normal standby mode (state 3), the power consumption does not exceed 0.2W (NTC sampling only).

[0134] (4) Low SOC protection threshold adjustment: When SOC < 30%, limit TEC heating power to 50%; when SOC < 20%, turn off TEC heating function to retain sufficient power to maintain normal communication and control functions of the equipment.

[0135] (5) Compact installation and fit: The external dimensions are 180mm×120mm×90mm, which fits the standard battery compartment of the power distribution switch equipment. The weight is about 1.2kg (including the thermal management system), which meets the weight restriction requirements for mounting and installation.

[0136] Example 6: 24V 12Ah outdoor equipment backup battery module (8S2P parallel structure).

[0137] This embodiment uses a 24V 12Ah lithium iron phosphate battery module as an example, employing IFR32700 type 6Ah cylindrical lithium iron phosphate cells, arranged in 8 series and 2 parallel (8S2P) configurations, for a total of 16 cells. This module is suitable for scenarios requiring 24V power supply and medium capacity, such as power distribution terminals (DTUs), small backup power for communication base stations, and online monitoring of transmission lines. The core significance of this embodiment lies in verifying the applicability of the thermal management system of this invention to battery modules with multiple parallel branches (P≥2).

[0138] The thermal management characteristics of the parallel structure module are as follows: (1) Heating characteristics of parallel cells: In the 8S2P module, each parallel branch consists of 8 cells connected in series. After the two branches are connected in parallel, the total heating power is about twice that of the 8S1P module of the same specification (the internal resistance is halved by parallel connection, but the discharge current is doubled. The heating power P=I²R is basically proportional to the number of parallel connections, where I represents the discharge current and R represents the total resistance). However, there are a total of 16 cells in the two parallel branches, and the total heat dissipation area is also about twice that of the 8S1P module. Therefore, the heat density per unit area is comparable to that of a single parallel branch module, and the TEC cooling / heating power requirement does not need to be simply doubled.

[0139] (2) TEC chip configuration principle: According to the parallel configuration coefficient method of the present invention, the single parallel branch of the 24V12Ah module is based on 2 TEC chips (corresponding to 24V6Ah, 8S1P), the number of parallel connections P=2, and the configuration coefficient is 0.7. Then the number of TEC chips = 2×2×0.7=2.8, which is rounded to 3 chips. However, considering that the heat generation of a single 6Ah small-capacity cell is lower than that of a 20Ah / 40Ah large single cell, the actual configuration of 2 TEC1-12706 chips in this embodiment can meet the thermal management requirements of the full temperature range from -40℃ to 70℃, which reflects the flexibility of the configuration coefficient method in the range of 0.6~0.8.

[0140] (3) NTC Temperature Sensor Arrangement: The cell temperatures of the two branches in the parallel module may differ (especially when a cell with high internal resistance exists in one branch). In this embodiment, one cell surface NTC sensor is arranged in each of the two parallel branches (NTC1 is located in branch A, and NTC3 is located in branch B). The temperature difference between the two cells is compared. Determine the parallel equilibrium state. When At this time, the thermal management controller reports an equalization alarm via RS485 / Modbus. NTC2 and NTC4 are still located on the cold and hot sides of the TEC, respectively, and their functions are the same as in Example 1.

[0141] (4) Thermal pad design for 32700 small-diameter cells: The IFR32700 cell has a diameter of Φ32mm and an arc curvature greater than that of a 40Ah / 20Ah large single-cell cell (Φ46mm), resulting in a larger gap between it and the planar thermally conductive aluminum plate. In this embodiment, a 0.3mm thick phase change thermal pad (thermal conductivity ≥3W / (m·K)) is used to fill the microscopic gaps during phase change at temperatures above 60℃. Due to the small diameter of the 32700 cell, the width of a single row after two cells are arranged side by side is approximately 32×2+gap=70mm. The thermally conductive aluminum plate can cover the arc surface of two parallel cells, and the TEC cooling / heating efficiency is comparable to that of a single row of large single-cell cells.

[0142] (5) Thermal performance estimation: At -40℃, the heating power of 2 TEC chips is approximately 28W, the total weight of 16 6Ah cells is approximately 3.2kg, the heat capacity is approximately 1.6kJ / K, and it takes approximately 35~50 minutes to heat up from -40℃ to 0℃. At 70℃, the cooling power of 2 TEC chips is approximately 45W, which can keep the cell temperature below 48℃. Low SOC protection threshold: When SOC < 25%, the TEC heating power is limited to 50%; when SOC < 15%, the TEC heating function is turned off.

[0143] This embodiment verifies the applicability of the present invention to multiple parallel branches (8S2P) and small-capacity cylindrical cells (IFR32700 6Ah). Similarly, the thermal management system of the present invention can be extended to other parallel combinations, such as 8S3P 24V18Ah (32700 6Ah×3 parallel), 4S2P 12V12Ah (32700 6Ah×2 parallel), 15S2P 48V40Ah (20Ah×2 parallel), etc., all of which are within the protection scope of the present invention.

[0144] Example 7: 48V 20Ah square-shell battery cell module (communication base station scenario).

[0145] This embodiment uses a 48V 20Ah lithium iron phosphate battery module as an example, employing square-shaped lithium iron phosphate cells (3.2V / 20Ah, approximately 27mm × 70mm × 130mm), arranged in 15 series and 1 parallel (15S1P) configurations, for use as a backup power supply for outdoor cabinets of 5G communication base stations. The square-shaped cell is the most common standardized cell shape in the industry, and this invention is also applicable to it.

[0146] The thermal management characteristics of the square-shell battery cell module are as follows: (1) Advantages of planar thermal coupling: The large surface of the square-shell battery cell is planar, and the TEC cold side can directly achieve surface contact thermal coupling with the large surface of the battery cell through a thin layer of thermally conductive silicone grease (0.1mm~0.2mm). The interface thermal resistance is significantly lower than that of cylindrical battery cells (cylindrical battery cells need to fill the arc gap with a phase change thermal pad, and the interface thermal resistance is about 0.15~0.25K / W; the interface thermal resistance of square-shell thermally conductive silicone grease is about 0.05~0.10K / W). Therefore, the temperature control efficiency of the square-shell battery cell module is higher for the same TEC power.

[0147] (2) Small cell spacing and concentrated thermal coupling: The square-shaped cells are closely arranged, with a gap of only about 1~2mm between cells. The TEC cooling / heating effect can be quickly transferred to all cells, and the temperature uniformity is better than that of cylindrical cell modules. The temperature difference between the cells inside the module in this embodiment... Superior to cylindrical cell modules .

[0148] (3) Sheet metal housing application: Sheet metal housings (steel plate material) are commonly used in communication base station cabinets. This invention can be directly integrated into the inside of the sheet metal housing. The insulation layer is attached to the inner wall of the sheet metal housing, and the TEC hot surface is thermally connected to the sheet metal housing through heat dissipation fins. The strength and EMI shielding performance of the sheet metal housing are superior to those of the aluminum alloy housing, making it suitable for communication base station scenarios.

[0149] (4) The TEC configuration is the same as in Example 2 (3 TEC1-12706 chips), but due to the higher thermal coupling efficiency of the square-shell battery cell, the actual temperature control effect is better than that of the cylindrical battery cell module. At an ambient temperature of 70°C, 3 TEC chips can maintain the battery cell temperature below 45°C; at an ambient temperature of -40°C, it takes about 30 to 40 minutes for the battery cell to heat up from -40°C to 0°C.

[0150] Example 8: 24V 12Ah soft-pack battery module (online monitoring scenario).

[0151] This embodiment uses a 24V 12Ah lithium iron phosphate battery module as an example, employing pouch-type lithium iron phosphate cells (3.2V / 12Ah, aluminum-plastic film encapsulation, approximately 10mm × 80mm × 120mm), arranged in 8 series and 2 parallel (8S2P) configurations, totaling 16 cells. It is suitable for scenarios such as small-scale backup power for communication base stations and online monitoring of transmission lines. Pouch-type cells have advantages such as high energy density, light weight, and flexible shape, and are also applicable to this invention.

[0152] The thermal management characteristics of pouch cell modules are as follows: (1) Ultra-thin thermal interface design: The outer surface of the soft-pack battery cell is an aluminum-plastic film, which is soft and cannot withstand large mechanical pressure. In this embodiment, a 0.1mm thick ultra-thin phase change thermal conductive sheet (thermal conductivity ≥3W / (m·K)) is attached to the surface of the soft-pack battery cell. The TEC cold side is thermally coupled to the phase change thermal conductive sheet through a thermally conductive aluminum plate. The phase change thermal conductive sheet undergoes a phase change above 60℃, filling the micro-unevenness of the aluminum-plastic film surface, reducing the interface thermal resistance, and avoiding excessive pressure on the soft-pack battery cell.

[0153] (2) Application of Engineering Plastic Housing: Online monitoring equipment is usually installed on poles or pipelines in the field, and there are strict limitations on the weight of the housing. This embodiment uses an engineering plastic (ABS+PC alloy) housing, which weighs about 0.8 kg (an aluminum alloy housing of the same size weighs about 1.5 kg), significantly reducing the installation burden. The thermal insulation performance of the engineering plastic housing is better than that of the metal housing (thermal conductivity of about 0.2 W / (m·K)), which helps to further reduce the introduction of ambient heat; however, the heat resistance of engineering plastic is poor, and the heat dissipation fins of the TEC hot surface need to be thermally connected to the TEC hot surface through an embedded metal frame to avoid heat accumulation that could cause the housing to deform.

[0154] (3) Temperature uniformity characteristics of pouch cells: Pouch cells have a large contact area between the internal electrode layer and the electrolyte, resulting in a more uniform internal temperature distribution than cylindrical cells, which is beneficial for refined control of TEC thermal management. The temperature difference within the cells of the module in this embodiment... It is the best among all types of battery cell shapes.

[0155] (4) The TEC configuration is similar to that in Examples 4 and 6 (2 TEC1-12706 cells). In an environment of 70°C, the cell temperature can be maintained below 48°C; in an environment of -40°C, it takes about 40 to 55 minutes for the cell to heat up from -40°C to 0°C. Low SOC protection threshold: When SOC < 25%, the TEC heating power is limited to 50%; when SOC < 15%, the TEC heating function is turned off.

[0156] Example 9: TEC / TEG thermoelectric power generation recovery mode of 48V38Ah power distribution terminal module.

[0157] This embodiment further illustrates the TEC / TEG bidirectional energy conversion function on the basis of the 48V38Ah lithium iron phosphate module in Embodiment 1. In areas with large diurnal temperature differences such as deserts and gobi, the ambient temperature can reach 70°C during summer daytime and drop below 30°C at night. Due to the large heat capacity of the battery module, the temperature change of the cells lags behind the ambient temperature. During the high-temperature period in the daytime (T_env=70°C, T_cell=35°C), the thermal management controller determines that T_env>T_cell+35°C, which meets the TEG start condition, and switches the TEC to the thermoelectric power generation mode. At this time, heat flows from the high-temperature environment through the heat dissipation fins, the TEC hot side, the TEC cold side, and the thermally conductive aluminum plate to the cells, generating a Seebeck voltage across the TEC. Six TEC1-12710 units are in this state, the open-circuit voltage of each unit is about 0.7V, which is regulated to the 48V bus voltage through series connection and a DC-DC boost circuit, with an output power of about 5~15W. This electric energy is directly used to supplement battery charging or maintain the power consumption of the BMS and the communication module. After the ambient temperature drops at night, the TEG mode is exited when T_env<T_cell+10°C. Actual measurement shows that under the condition of a diurnal temperature difference of 40°C, the daily power generation of the TEG mode is about 80~150Wh, which is equivalent to 2%~4% of the rated capacity of the module.

[0158] Embodiment 10: Predictive pre-compensation and COP optimization for a 48V20Ah module of a communication base station.

[0159] This embodiment takes the 48V20Ah communication base station module of Embodiment 2 as an example to illustrate the functions of ambient temperature predictive pre-compensation and adaptive COP optimization. The network management system of the communication base station sends the ambient temperature prediction data for the next 2 hours to the BMS through the RS485 / Modbus interface (for example: at 13:00, it is predicted that the temperature in the base station cabinet will reach 55°C at 14:00). The thermal management controller starts TEC refrigeration in advance when the cell temperature is 32°C at 13:30, instead of waiting until the cell temperature reaches the 40°C threshold. Through feedforward control, the cell temperature is stabilized below 38°C at 14:00, avoiding the overshoot above 45°C caused by thermal inertia in traditional feedback control. At the same time, the COP optimizer queries the TEC characteristic curve based on real-time and T_cell to select the operating current that maximizes the COP. When T_cell=35°C and T_env=55°C, the optimizer reduces the operating current from 6A to 4.2A, and the cooling capacity from 72W to 55W, but the COP increases from 0.9 to 1.3, reducing the unit cooling power consumption by about 30%. Combining predictive pre-compensation and COP optimization, the daily TEC energy consumption of the system is reduced by more than 35%.

[0160] The above 10 embodiments cover three voltage levels (12V / 24V / 48V), single parallel (1P) and multi-parallel (2P and above) topologies, and lithium-ion cells with different single-cell capacity specifications. The cell shapes include three types: cylindrical, square, and pouch. The shell materials include aluminum alloy, sheet metal, stainless steel (which can be replaced in rail transit scenarios), engineering plastics, and other options. They correspond to various typical power industry backup power supply application scenarios such as power distribution terminals, communication base stations, rail transit, online monitoring, and smart switches, fully verifying the wide applicability and scalability of the TEC wide temperature range thermal management system of this invention.

[0161] It should be noted that the above embodiments all use lithium iron phosphate (LFP) cells as examples, but the TEC wide-temperature-range thermal management system of the present invention is also applicable to ternary lithium (NCM / NCA), lithium titanate (LTO), and sodium-ion battery cells. The different temperature management requirements of cells with different chemical systems are adaptively adjusted through BMS configuration parameters. (1) Lithium iron phosphate (LFP) cells: charging temperature range 0~45℃, discharging temperature range -20~60℃, suitable for power distribution terminals and communication base station scenarios, which is the preferred embodiment.

[0162] (2) Ternary lithium (NCM / NCA) cells: charging temperature range 0~45℃, discharge temperature range -10~55℃, high temperature thermal management requirements are more urgent (lower thermal runaway temperature), high temperature active cooling threshold can be adjusted down to 50℃, suitable for communication base stations and rail transit scenarios with high energy density requirements.

[0163] (3) Lithium titanate (LTO) cells: The discharge temperature range can reach -30~60℃. The low temperature performance is better than that of lithium iron phosphate, but TEC cooling is still required to maintain cycle life in high temperature environments. The low temperature heating power can be reduced to 50% of that of LFP. It is suitable for power distribution terminals and online monitoring equipment in extreme low temperature areas (such as along the Qinghai-Tibet Railway).

[0164] (4) Sodium-ion battery cells: charging temperature range -10~45℃, discharging temperature range -30~55℃, with good low-temperature performance and cost advantages. The low-temperature heating threshold can be adjusted down to -30℃, which is suitable for low-cost online monitoring and small backup power scenarios for communication base stations.

[0165] The temperature threshold, heating power ratio, and SOC protection parameters of the battery cells with different chemical systems can all be flexibly adjusted through the BMS configuration parameters without modifying the hardware structure of the thermal management system, which reflects the design concept of hardware unification and software adaptation of this invention.

[0166] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal. Unless otherwise specified, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or terminal that includes that element.

[0167] Of course, those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware (such as a processor, controller, etc.). This program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The computer-readable storage medium can be a memory, magnetic disk, optical disk, etc.

[0168] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A wide-temperature-range thermal management method for backup batteries in the power industry, characterized in that, The wide-temperature-range thermal management method for backup batteries in the power industry includes: The temperature acquisition module acquires the cell temperature, TEC cold surface temperature, and TEC hot surface temperature of the backup battery in the power industry in real time. Based on the cell temperature and a preset temperature threshold, the thermal management controller determines the operating mode of the TEC, which includes a low-temperature heating mode, a normal standby mode, and a high-temperature cooling mode. According to the operating mode, the power supply direction of the TEC drive circuit is controlled by the thermal management controller to drive the TEC to operate according to the operating mode; Based on the deviation between the cell temperature and the preset target temperature, the PWM duty cycle of the TEC drive circuit is controlled by the thermal management controller to adjust the input power of the TEC until the cell temperature reaches the preset target temperature. Based on the cell temperature, the TEC cold surface temperature, and the TEC hot surface temperature, thermal management is performed on the power industry backup battery using a cold start strategy, a low SOC protection strategy, a TEC thermoelectric power generation recovery strategy, a pre-compensation strategy, and a control parameter configuration strategy.

2. The wide-temperature-range thermal management method for backup batteries in the power industry according to claim 1, characterized in that, The preset temperature threshold includes a first preset temperature threshold and a second preset temperature threshold, wherein the first preset temperature threshold is less than the second preset temperature threshold. The step of determining the operating mode of the TEC (Chemical Temperature Controller) based on the cell temperature and a preset temperature threshold specifically includes: The operating mode of the TEC is determined by comparing the cell temperature with the first preset temperature threshold and the second preset temperature threshold using a thermal management controller. If the cell temperature is lower than the first preset temperature threshold, the TEC is determined to be in low-temperature heating mode. If the cell temperature is not less than the first preset temperature threshold and not greater than the second preset temperature threshold, the TEC is determined to be in normal standby mode. If the cell temperature is greater than the second preset temperature threshold, the TEC is determined to be in high-temperature cooling mode.

3. The wide-temperature-range thermal management method for backup batteries in the power industry according to claim 2, characterized in that, The step of controlling the power supply direction of the TEC drive circuit through the thermal management controller according to the operating mode, so as to drive the TEC to operate according to the operating mode, specifically includes: When the operating mode of the TEC is determined to be low-temperature heating mode, the power supply direction of the TEC drive circuit is controlled to the first power supply direction by the thermal management controller, so as to drive the TEC to be in low-temperature heating mode. The TEC transfers heat to the battery cell and reduces the heat loss of the battery cell to the environment through the heat insulation structure. When the TEC is determined to be in normal standby mode, the thermal management controller controls the TEC drive circuit to stop supplying power, so that the TEC is in normal standby mode and the TEC stops working; When the operating mode of the TEC is determined to be high temperature cooling mode, the power supply direction of the TEC drive circuit is controlled to the second power supply direction by the thermal management controller, so as to drive the TEC to be in high temperature cooling mode. The TEC extracts heat from the battery cell and blocks ambient heat from entering the battery cell from the non-TEC covered surface through the heat insulation structure. The TEC is disposed on one side of the battery cell, and the heat insulation structure is disposed on the non-TEC covered side of the battery cell. The TEC and the heat insulation structure form a synergistic thermal management structure.

4. The wide-temperature-range thermal management method for backup batteries in the power industry according to claim 3, characterized in that, When the cell temperature is below the extreme low temperature threshold, a cold start strategy is executed, which includes: The TEC is preheated using a first preset low power ratio of its rated power as the heating power. When the first temperature difference between the hot surface temperature and the cold surface temperature of the TEC is lower than the thermal stress threshold, the heating power of the TEC is gradually increased to the rated power at a preset rate. When the first temperature difference is greater than the preset upper limit of temperature difference, the heating power of the TEC is paused; when the first temperature difference is less than the preset lower limit of temperature difference, the heating power of the TEC continues to be increased. During the execution of the cold start strategy, the battery management system locks the charging and discharging functions of the power industry backup battery. When the cell temperature is greater than the first preset unlocking temperature, the battery management system unlocks the charging function. When the cell temperature is greater than the second preset unlocking temperature, the battery management system unlocks the discharging function.

5. The wide-temperature-range thermal management method for backup batteries in the power industry according to claim 4, characterized in that, The wide-temperature-range thermal management method for backup batteries in the power industry also includes a hardware over-temperature protection strategy, which includes: When the temperature of the TEC hot surface exceeds the preset hot surface protection threshold, the power supply to the TEC is cut off by a hardware comparator. When the cell temperature exceeds a preset cell protection threshold, the charging and discharging circuit of the power industry backup battery is cut off by the battery management system, so that the power industry backup battery enters a thermal protection state.

6. The wide-temperature-range thermal management method for backup batteries in the power industry according to claim 5, characterized in that, The low SOC protection strategy includes: During the period when the TEC is in low-temperature heating mode, the SOC value of the power industry backup battery is monitored in real time by the thermal management controller; When the SOC value is lower than the first preset SOC threshold, the heating power of the TEC is reduced to a second preset low power ratio of the rated power; When the SOC value is lower than the second preset SOC threshold, the heating function of the TEC is turned off until the external charging is restored, at which point the heating function of the TEC is turned on again.

7. The wide-temperature-range thermal management method for backup batteries in the power industry according to claim 6, characterized in that, The TEC thermoelectric power recovery strategy includes: When the ambient temperature is higher than the cell temperature and the second temperature difference between the ambient temperature and the cell temperature exceeds the preset TEG start-up threshold, the TEC is switched to thermoelectric power generation mode by the thermal management controller. In thermoelectric power generation mode, an electromotive force is generated by the temperature difference gradient formed between the heat insulation structure and the TEC. The TEC, as a thermoelectric power generation device, converts ambient heat into electrical energy. After being regulated by a DC-DC converter circuit, the electrical energy is used to additionally charge the power industry backup battery or maintain the battery management system at minimum power consumption. Based on the first temperature difference and the ambient temperature, query the pre-stored TEG output characteristic curve, and estimate the current recoverable power based on the TEG output characteristic curve. When the current recoverable power is greater than a preset ratio of the input power required by the TEC to offset the same heat flow in high-temperature cooling mode, the TEC preferentially operates in thermoelectric power generation mode. The TEG output characteristic curve is dynamically updated according to the TEC model, aging state, and cell chemical system identification.

8. The wide-temperature-range thermal management method for backup batteries in the power industry according to claim 7, characterized in that, The pre-compensation strategy includes: Receive ambient temperature prediction data through the BMS communication interface; When the predicted ambient temperature data within a preset time period is less than the first preset temperature threshold or greater than the second preset temperature threshold, and the cell temperature is not less than the first preset temperature threshold and not greater than the second preset temperature threshold, the thermal management controller controls the TEC drive circuit to drive the TEC to enter the low-temperature heating mode or high-temperature cooling mode in advance.

9. The wide-temperature-range thermal management method for backup batteries in the power industry according to claim 8, characterized in that, The wide-temperature-range thermal management method for backup batteries in the power industry also includes an adaptive optimization strategy, which includes: The adaptive COP optimizer built into the thermal management controller queries the pre-stored TEC characteristic parameter table based on the first temperature difference, the cell temperature, and the cell chemical system identifier. Obtain the target operating current or target PWM duty cycle that maximizes the instantaneous energy efficiency ratio (COP) of the TEC from the TEC characteristic parameter table; The thermal management controller controls the TEC drive circuit to operate at the target operating current or the target PWM duty cycle so that the instantaneous energy efficiency ratio (COP) of the TEC reaches its maximum value.

10. The wide-temperature-range thermal management method for backup batteries in the power industry according to claim 9, characterized in that, The wide-temperature-range thermal management method for backup batteries in the power industry also includes early warning of thermal runaway and TEC emergency suppression strategies, which include: Based on the cell temperature, the TEC cold surface temperature and the TEC hot surface temperature, the cell temperature change rate, the first temperature difference change rate and the temperature gradient at different locations of the cell are calculated in real time. When the cell temperature change rate or the first temperature difference change rate is greater than the first preset warning threshold or the temperature gradient is greater than the second preset warning threshold, it is determined that there is an early risk of thermal runaway, and the TEC is switched to emergency suppression mode through the thermal management controller. In emergency suppression mode, the TEC actively cools the abnormal area of ​​the cell at maximum safe power, and disconnects the charging and discharging circuit of the power industry backup battery through the battery management system and reports an alarm.

11. The wide-temperature-range thermal management method for backup batteries in the power industry according to claim 10, characterized in that, The wide-temperature-range thermal management method for backup batteries in the power industry also includes a temperature control strategy, which includes: The real-time instantaneous energy efficiency ratio (COP) of the TEC is calculated based on the first temperature difference. When the real-time instantaneous energy efficiency ratio (COP) is less than a preset COP threshold, the input power of the TEC is reduced or the TEC is switched to passive cooling mode by the thermal management controller. When the first temperature difference is greater than the preset reversal determination threshold, it is determined that the cooling direction of the TEC is reversed, and the power supply to the TEC is cut off by the thermal management controller; A temperature dead zone is set with the preset target temperature as the center. When the cell temperature is within the temperature dead zone, the thermal management controller maintains the input power of the TEC at a constant level. A first temperature hysteresis and a second temperature hysteresis are set based on the first preset temperature threshold and the second preset temperature threshold, respectively, to prevent the TEC from frequently switching working modes at the first preset temperature threshold or the second preset temperature threshold. The temperature control strategy architecture includes state machine control or continuous control, and the temperature control strategy algorithm includes PID closed-loop control, fuzzy control, ON-OFF hysteresis control, or lookup table method.

12. The wide-temperature-range thermal management method for backup batteries in the power industry according to claim 11, characterized in that, The control parameter configuration strategy includes: Multiple sets of thermal management parameters corresponding to various cell chemical systems are pre-stored. Each set of thermal management parameters includes the first preset temperature threshold, the second preset temperature threshold, the extreme low temperature threshold, the first preset low power ratio, the thermal stress threshold, the preset rate, the preset upper limit of temperature difference, the preset lower limit of temperature difference, the first preset unlocking temperature, the second preset unlocking temperature, the preset hot surface protection threshold, the preset cell protection threshold, the first preset SOC threshold, the second preset low power ratio, the second preset SOC threshold, the preset TEG start-up threshold, the preset ratio, the preset future duration, the first preset warning threshold, the second preset warning threshold, the preset COP threshold, the preset reversal judgment threshold, the first temperature hysteresis, and the second temperature hysteresis. Obtain the cell chemical system identifier corresponding to the backup battery for the power industry, and based on the cell chemical system identifier, call the target thermal management parameter group corresponding to the cell chemical system identifier from multiple pre-stored thermal management parameter groups; Thermal management of the power industry backup battery is performed through a thermal management controller based on the target thermal management parameter set. The battery cell chemistry system includes lithium iron phosphate batteries, ternary lithium batteries, lithium titanate batteries, and sodium-ion batteries. The thermal management parameter group supports online updates and configuration adjustments through the BMS communication interface.

13. A wide-temperature-range thermal management system for a backup battery in the power industry, wherein the wide-temperature-range thermal management system for the backup battery in the power industry is used to implement the wide-temperature-range thermal management method for a backup battery in the power industry according to any one of claims 1-12, characterized in that, The wide-temperature-range thermal management system for the backup battery in the power industry includes: Backup batteries for the power industry are composed of cells connected in different series and parallel combinations. The TEC is disposed on the surface of the battery cell and is thermally coupled to the battery cell through a thermally conductive interface layer or a thermally conductive component or through direct contact. A thermal insulation structure is provided on the non-TEC covered surface of the battery cell to reduce uncontrolled heat conduction between the environment and the battery cell; A heat dissipation device is disposed on the hot surface of the TEC to conduct heat from the hot surface of the TEC to the environment; The temperature acquisition module includes multiple temperature sensors, which are respectively disposed on the surface of the battery cell, the cold side of the TEC, and the hot side of the TEC, and are used to acquire the battery cell temperature, the TEC cold side temperature, and the TEC hot side temperature, respectively. A thermal management controller is electrically connected to the temperature acquisition module and the TEC drive circuit. Based on the cell temperature, the TEC cold surface temperature and the TEC hot surface temperature, it outputs a PWM control signal to the TEC drive circuit through a temperature control strategy to adjust the TEC's operating mode and input power. The TEC drive circuit is electrically connected to the thermal management controller and the TEC, and is used to drive the TEC to work in low-temperature heating mode, normal standby mode or high-temperature cooling mode. The thermal insulation structure and the TEC form a synergistic thermal management structure.

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