Temperature control method, device and cable for connecting energy storage battery pack

Abstract

The present invention provides a temperature control method, device and cable for connecting a cable of an energy storage battery pack, belonging to the technical field of energy storage systems. The temperature control method for connecting a cable of an energy storage battery pack of the present invention comprises: obtaining the temperature of each cable through a temperature-sensitive element at the connection between the battery pack of each region and the connecting cable under a target event, and obtaining the ambient temperature of each battery pack of each region through an ambient temperature sensor; based on the temperature of each cable and each ambient temperature, identifying the temperature characteristics of the battery pack of each region in the energy storage system; the temperature characteristics include peak temperature characteristics and cumulative temperature characteristics; based on the power requirements of the target event, the battery state of charge of the battery pack, the battery health status and the temperature characteristics of the battery pack of each region, controlling the temperature of the battery pack of each region by monitoring the temperature of the cable connection. The method of the present invention can more accurately monitor the temperature of the energy storage system, control the charge and discharge current and achieve temperature management.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage systems, and in particular to a temperature control method, device and cable for connecting an energy storage battery pack. Background Art

[0002] The increase in temperature in the energy storage system will cause the electrochemical reaction of the battery to accelerate. In this way, in a high temperature environment, the aging of the battery will accelerate, the internal resistance will increase, and the capacity decay will be more obvious. Low-temperature batteries may not be able to discharge or charge normally due to low chemical reaction efficiency caused by too low temperature. Uneven temperature will accelerate the aging of the battery cells in the battery pack and shorten its cycle life. Batteries also have potential safety risks in the case of overcharge, over-discharge or overheating, such as electrolyte leakage, short circuit and even explosion. The temperature monitoring system can detect abnormal temperature changes in time and take measures through the BMS and thermal management system, such as cutting off the current and increasing heat dissipation, to prevent safety accidents.

[0003] Reasonable control of the battery operating temperature can effectively improve its charging and discharging efficiency and extend its service life. Existing energy storage systems are generally equipped with temperature sensors that can record temperature data during the operation of the equipment, providing an important basis for fault diagnosis and analysis, and helping to find problems and perform repairs in a timely manner. However, in the prior art, temperature data usually monitors the ambient temperature or the temperature of the battery cell itself. However, the ambient temperature and battery cell temperature cannot accurately reflect the temperature at the connection between the battery pack and the connecting cable.

[0004] In certain cases, overheating problems at the battery pack or cable connection cannot be discovered in time. When the temperature at the connection is too high, it may cause problems such as increased contact resistance and aging of cable insulation, leading to safety accidents. Cable connections are key parts for current transmission, and heat is generated when current passes through. If the temperature at the connection is too high, it may cause poor contact and increased resistance, further exacerbating heating and even causing faults such as short circuits. Summary of the invention

[0005] The present invention provides a temperature control method, device and cable for connecting an energy storage battery pack, which are used to solve the defect of lack of monitoring of the temperature at the cable connection in the prior art, and achieve the effect of accurately controlling the charging and discharging current and achieving temperature management.

[0006] The present invention provides a temperature control method for a cable connecting an energy storage battery pack, comprising:

[0007] Under the target event, the temperature of each cable is obtained through the temperature-sensitive element at the connection between the battery pack in each area and the connecting cable, and the ambient temperature of each battery pack in each area is obtained through the ambient temperature sensor;

[0008] Based on the temperature of each cable and each ambient temperature, identifying the temperature characteristics of the battery packs in each area of ​​the energy storage system; the temperature characteristics include peak temperature characteristics and cumulative temperature characteristics;

[0009] The temperature of the battery packs in each area is controlled based on the power requirement of the target event, the battery state of charge and the battery health state of the battery pack and the temperature characteristics of the battery packs in each area.

[0010] According to a temperature control method for a cable connected to an energy storage battery pack provided by the present invention, the peak temperature characteristic is used to represent the maximum value between the cable temperature and the ambient temperature; the cumulative temperature characteristic is used to represent the cumulative heat load caused by continuous heating; the cumulative temperature characteristic Q is expressed as:

[0011] ;

[0012] Among them, t1 and t2 represent the starting and ending time of the cumulative time period respectively, T conn is the junction temperature, T env is the ambient temperature.

[0013] According to a temperature control method of a cable connecting an energy storage battery pack provided by the present invention, the temperature of the battery packs in each area is controlled based on the power requirement of the target event, the battery state of charge of the battery pack, the battery health state and the temperature characteristics of the battery packs in each area, including:

[0014] Based on the power requirement of the target event, the battery state of charge and the battery health state of the battery pack, determine the lower limit value of the current at the connection between the battery pack in each area and the connecting cable; based on the temperature characteristics of the battery pack in each area, determine the upper limit value of the temperature at the connection between the battery pack in each area and the connecting cable;

[0015] Based on the lower current limit value at the connection between the battery packs in each area and the connecting cables and the upper temperature limit value at the connection between the battery packs in each area and the connecting cables, the current at the connection between the battery packs in each area and the connecting cables and the thermal management measures of the battery packs in each area are adjusted to control the temperature of the battery packs in each area.

[0016] According to a temperature control method for a cable connecting an energy storage battery pack provided by the present invention, the lower limit value of the current at the connection between the battery pack in each area and the connecting cable is determined based on the power requirement of the target event, the battery state of charge of the battery pack, and the battery health state, including:

[0017] Based on the power requirement of the target event, determining the minimum power that the energy storage system needs to provide;

[0018] Determining a current range output by the battery pack in a current state based on a battery state of charge and a battery health state of the battery pack;

[0019] The lower limit value of the current at the connection between the battery pack and the connecting cable is determined based on the current range output from the battery pack for the minimum power that the energy storage system needs to provide.

[0020] According to a temperature control method for a cable connecting an energy storage battery pack provided by the present invention, the temperature upper limit value of the connection between the battery pack in each area and the connecting cable is determined based on the temperature characteristics of the battery pack in each area, including:

[0021] Based on the temperature characteristics of the battery packs in each area, identify the heat dissipation capacity of each area;

[0022] Based on the heat dissipation capacity of each area, the upper temperature limit of the connection point between the battery pack and the connection cable in each area is determined.

[0023] According to a temperature control method for a cable connecting an energy storage battery pack provided by the present invention, the target event includes at least one of a power grid frequency regulation event, a peak shaving and valley filling event, and an energy grid connection event.

[0024] The present invention also provides a cable, comprising: a temperature signal line, wherein each signal acquisition terminal of the temperature signal line is respectively connected to the temperature sensitive element at the connection between each regional battery pack and the connecting cable in any of the above-mentioned temperature control methods for cables connecting energy storage battery packs.

[0025] The present invention further provides a temperature control device for a cable connecting an energy storage battery pack, wherein the device uses the temperature control method for a cable connecting an energy storage battery pack as described in any one of the above items to control the temperature of battery packs in each area of ​​the energy storage system, and the device comprises:

[0026] An acquisition module is used to acquire the temperature of each cable through a temperature-sensitive element at a connection point between a battery pack in each area and a connecting cable under a target event, and to acquire the ambient temperature of each battery pack in each area through an ambient temperature sensor;

[0027] A first processing module, for identifying temperature characteristics of battery packs in each area of ​​the energy storage system based on the temperature of each cable and each ambient temperature; the temperature characteristics include peak temperature characteristics and cumulative temperature characteristics;

[0028] The second processing module is used to control the temperature of the battery packs in each area based on the power requirement of the target event, the battery state of charge and the battery health state of the battery pack and the temperature characteristics of the battery packs in each area.

[0029] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, a temperature control method for a cable connected to an energy storage battery pack as described in any one of the above is implemented.

[0030] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the temperature control method for a cable connected to an energy storage battery pack as described in any one of the above.

[0031] The present invention also provides a computer program product, comprising a computer program, which, when executed by a processor, implements any of the above-mentioned methods for controlling the temperature of a cable connected to an energy storage battery pack.

[0032] The temperature control method, device and cable of the cable connecting the energy storage battery pack provided by the present invention can monitor the temperature of the energy storage system more accurately by monitoring the temperature of the cable connection, timely discover the hidden danger of overheating, prevent thermal runaway, and improve safety; at the same time, based on the cable temperature and ambient temperature, combined with the power requirements of specific target events and the battery charge state and health state of the battery packs in each area, the charging and discharging currents are accurately controlled and temperature management is achieved, thereby optimizing system performance and extending equipment life. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 This is one of the flow charts of the temperature control method of the cable connected to the energy storage battery pack provided by the present invention;

[0035] Figure 2 This is a second flow chart of the temperature control method of the cable connected to the energy storage battery pack provided by the present invention;

[0036] Figure 3 It is a structural schematic diagram of a temperature control device for a cable connected to an energy storage battery pack provided by the present invention;

[0037] Figure 4 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Combine the following Figure 1-Figure 4 The present invention describes a temperature control method, a device and a cable for connecting an energy storage battery pack.

[0040] like Figure 1 As shown, the temperature control method of the cable connecting the energy storage battery pack according to the embodiment of the present invention mainly includes step 110, step 120 and step 130.

[0041] Step 110 , under the target event, the temperature of each cable is obtained through the temperature-sensitive element at the connection between the battery pack in each area and the connecting cable, and the ambient temperature of each battery pack in each area is obtained through the ambient temperature sensor.

[0042] The temperature data of the connection points are obtained in real time by installing temperature-sensitive elements at the connection points between the battery packs and the connection cables in each area. These temperature-sensitive elements can be temperature sensors such as thermocouples and thermal resistors, which can accurately sense the temperature changes at the connection points and convert the temperature signals into electrical signals or other transmittable signal forms for subsequent processing and analysis.

[0043] At the same time, the ambient temperature sensor is used to collect the temperature of the environment in which the battery packs are located in each area. The ambient temperature also has a certain impact on the temperature of the battery packs and connecting cables. For example, in a high temperature environment, the battery packs and connecting cables are more likely to heat up, while in a low temperature environment, the battery insulation problem may need to be considered.

[0044] Therefore, obtaining accurate ambient temperature data is crucial to fully evaluate the thermal status of the energy storage system.

[0045] Step 120 , based on the temperature of each cable and each ambient temperature, the temperature characteristics of the battery packs in each area of ​​the energy storage system are identified.

[0046] The temperature characteristics include peak temperature characteristics and cumulative temperature characteristics.

[0047] Analyze the collected temperature data of each cable to find out the temperature rise phenomenon that occurs in a short period of time, that is, the instantaneous peak temperature. This peak temperature may be caused by the heating of the resistance at the cable connection due to high current charging and discharging. For example, when the battery pack is running at a higher charge and discharge rate, the current in the connecting cable increases. According to Joule's law, the resistance at the cable connection will generate more heat, causing the temperature to rise rapidly and form a peak temperature. By monitoring and identifying these peak temperatures, the risk of overheating at the cable connection can be discovered in time.

[0048] In addition to the instantaneous peak temperature, it is also necessary to pay attention to the heat accumulation over a long period of time, that is, the cumulative heat. The amount of cumulative heat can be obtained by integrating or accumulating the cable temperature data over a period of time. Excessive cumulative heat may cause the material performance of the connecting cable to deteriorate, accelerate aging, and even cause serious consequences such as thermal runaway. For example, during a long period of high-load charging and discharging, even if the peak temperature each time is not too high, if the cumulative heat exceeds the tolerance of the cable material, it will still pose a threat to the safety of the cable and battery pack.

[0049] The cumulative heat characteristic can be calculated by integrating the temperature-time curve area within a certain time window (such as 10 minutes), reflecting the cumulative heat load caused by continuous heating.

[0050] In some possible implementations, the peak temperature characteristic is used to represent the maximum value between the cable temperature and the ambient temperature; the cumulative temperature characteristic is used to represent the cumulative heat load caused by continuous heating; the cumulative temperature characteristic Q is expressed as:

[0051] ;

[0052] Among them, t1 and t2 represent the starting and ending time of the cumulative time period respectively, T conn is the junction temperature, T env is the ambient temperature.

[0053] Step 130 , based on the power requirement of the target event, the battery state of charge, the battery health state of the battery pack, and the temperature characteristics of the battery pack in each area, control the temperature of the battery pack in each area.

[0054] After obtaining the temperature characteristics of the battery packs in each area, the corresponding control strategy is formulated in combination with the power requirements of the target event. If the peak temperature in a certain area is detected to be too high, it may be necessary to reduce the charge and discharge current in that area to reduce the heat generated at the cable connection and avoid further temperature increase. At the same time, heat dissipation measures can also be initiated, such as turning on the fan, starting the liquid cooling system, etc., to accelerate the dissipation of heat and restore the temperature to the normal range as soon as possible. For areas with large accumulated heat, in addition to taking heat dissipation measures, you can also consider adjusting the charge and discharge mode, such as reducing the charge and discharge rate, increasing the rest time, etc., to reduce the continued accumulation of heat.

[0055] It should be noted that the control strategy is not static, but needs to be dynamically adjusted according to real-time temperature data and power requirements. For example, when the load power demand changes, the charge and discharge current and heat dissipation measures need to be adjusted accordingly to ensure that the energy storage system can meet the power requirements while keeping the temperature of each area within a safe range. In addition, the differences between battery packs in different regions must also be considered. For example, battery packs in some areas may be more prone to overheating due to factors such as location and heat dissipation conditions, and temperature control and heat dissipation treatment need to be prioritized.

[0056] Under the premise of ensuring the system output power (such as 100kW), priority is given to preventing overheating risks and extending battery life. Constraints can include the connection temperature being less than or equal to a safety threshold (such as 80°C). The trigger condition for instantaneous peak temperature control can be that the instantaneous temperature in a certain area exceeds a threshold (such as 60°C), which can reduce the charge and discharge current of the battery module in the area (for example, from 100A to 70A) to reduce heat generation; then dynamically allocate power demand to modules in other areas with lower temperatures to maintain the total power unchanged.

[0057] In one example, if the cable temperature in area A reaches 65°C, the current in area A drops from 100A to 70A, and the currents in areas B and C increase by 15A each, ensuring that the total current is: 70+115+115=300A ​​(total power remains unchanged). The trigger condition for cumulative heat control can be that the cumulative heat Q in a certain area is close to the upper limit of control (such as 1000°C·min). The depth of charge and discharge in the area can be limited, such as adjusting the battery state of charge SOC range from 20%~80% to 30%~70%, and triggering active heat dissipation such as starting the liquid cooling system or increasing the fan speed.

[0058] Battery health status (SOH) can be evaluated by monitoring parameters such as the battery's internal resistance and capacity decay. For batteries with poor health status, stricter temperature control may be required to prevent overheating and accelerated battery aging. For example, when the battery's internal resistance increases to a certain extent, the charge and discharge current needs to be reduced to reduce battery heating.

[0059] The temperature control strategy can also be adjusted according to the battery's SOC. When the SOC is low, the battery's charge and discharge efficiency is low, and the charge and discharge current may need to be appropriately reduced to reduce heat generation; when the SOC is high, the battery's heat generation may increase, and heat dissipation measures need to be strengthened.

[0060] In high temperature environments, the battery pack is more likely to overheat, and heat dissipation measures need to be strengthened, such as increasing the fan speed, increasing the coolant flow of the liquid cooling system, etc. In low temperature environments, the battery's charging and discharging efficiency will decrease, and the heating system may need to be started to increase the battery temperature.

[0061] In addition, by monitoring the temperature of each single cell inside the battery pack, temperature balance control can be achieved. For single cells with higher temperatures, their charge and discharge currents can be appropriately reduced, and local heat dissipation measures can be initiated, such as adding fans or local cooling of liquid cooling systems.

[0062] In one example, the charge and discharge current and heat dissipation measures can be dynamically adjusted according to the load changes. When the load suddenly increases, the charge and discharge current may need to be increased in a short period of time, but at the same time, heat dissipation must be strengthened to prevent the battery pack from overheating; when the load decreases, the charge and discharge current can be appropriately reduced to reduce heat generation.

[0063] For example, when the power grid has special demands on the energy storage system, such as grid frequency regulation and peak regulation, it is necessary to adjust the charging and discharging power and temperature control strategy of the energy storage system according to the needs of the grid to ensure that the energy storage system meets the needs of the grid while the temperature of the battery packs in each area remains within a safe range.

[0064] In one example, an intelligent heat dissipation system is used, such as a system that automatically adjusts the fan speed or coolant flow rate according to the battery temperature. For example, when the battery temperature rises, the system automatically increases the fan speed or coolant flow rate to accelerate heat dissipation; when the battery temperature drops, the system automatically reduces the fan speed or coolant flow rate to save energy.

[0065] In another example, phase change materials can be used around the battery pack. When the battery temperature rises, the phase change material absorbs heat and undergoes a phase change to lower the battery temperature. When the battery temperature drops, the phase change material releases heat to keep the battery temperature stable.

[0066] In another example, the structural design of the battery pack can be optimized, such as increasing the air flow channel inside the battery pack to improve the heat dissipation efficiency. For example, a honeycomb structure is used to design the heat dissipation channel inside the battery pack to make the air flow smoother and take away more heat.

[0067] In another example, control can also be performed based on temperature prediction based on machine learning. The temperature change of the battery pack is predicted using a machine learning algorithm, and temperature control measures are taken in advance. For example, by collecting historical temperature data and operating data of the battery pack, training a machine learning model, predicting the temperature change trend of the battery pack in the future, and adjusting the charge and discharge current and heat dissipation measures in advance based on the prediction results.

[0068] In some possible implementations, the target event includes at least one of a power grid frequency regulation event, a peak load shaving event, and an energy grid connection event.

[0069] The goal of grid frequency regulation is to quickly respond to grid frequency changes, regulate grid power through the charging and discharging of energy storage systems, and maintain grid frequency stability. At this time, the energy storage system needs to quickly adjust the charging and discharging power according to the real-time frequency deviation and power demand of the grid to meet the requirements of grid frequency regulation.

[0070] The goal of peak load shaving is to balance the load of the power grid through the charging and discharging of the energy storage system, reduce the peak load of the power grid and increase the valley load. During the peak load period, the energy storage system discharges to provide power support to the power grid; during the valley load period, the energy storage system charges to store excess electricity.

[0071] The goal of renewable energy grid connection is to smooth the output power of renewable energy (such as solar energy and wind energy) and reduce the impact of its volatility and intermittency on the power grid. The energy storage system dynamically adjusts the charging and discharging power according to the power generation power of renewable energy and the demand of the power grid, making the output power of renewable energy more stable.

[0072] In some possible implementations, target events may also be classified according to system performance requirements, and target events include high-efficiency operation events and long-life operation events.

[0073] For example, the goal of the high-efficiency operation event is to improve the charging and discharging efficiency of the energy storage system and reduce energy loss. At this time, the charging and discharging current and heat dissipation measures can be optimized according to the temperature characteristics and power requirements of the battery pack, so that the battery pack operates within the optimal temperature range and the charging and discharging efficiency of the battery is improved.

[0074] For example, the goal of the long-life operation event is to extend the service life of the battery pack. At this time, it is necessary to consider the health status (SOH) and temperature characteristics of the battery pack to avoid overheating or overcooling of the battery pack and reduce the aging rate of the battery. For example, when the SOH of the battery pack is low, the charge and discharge current can be appropriately reduced to reduce the heat generated by the battery, while strengthening heat dissipation measures to keep the temperature of the battery pack stable.

[0075] In some possible implementations, the temperature of the battery packs in each region may be controlled based solely on factors of the power requirement of the target event, the battery state of charge of the battery pack, the battery state of health, and the temperature characteristics of the battery packs in each region.

[0076] In the grid frequency modulation scenario, the energy storage system needs to quickly respond to the power change requirements of the grid. When it is detected that the peak temperature of the battery pack in a certain area is too high and the grid frequency modulation power requirement is high, the charge and discharge current in the area can be appropriately reduced to reduce the heat generated at the cable connection and avoid further temperature increase. At the same time, start the heat dissipation measures in the area, such as turning on the fan or increasing the coolant flow of the liquid cooling system, to accelerate the heat dissipation and restore the temperature to the normal range as soon as possible.

[0077] In the solar power generation and energy storage system, the solar power generation power is large during the day, and the excess power needs to be stored in the battery pack. At this time, if it is found that the accumulated heat of the battery pack in a certain area is large, and the power requirement cannot be greatly reduced, you can consider adjusting the charge and discharge mode, such as reducing the charge and discharge rate, and starting heat dissipation measures to reduce the continued accumulation of heat.

[0078] When the SOC of the battery pack is low, the battery's charge and discharge efficiency is low and the heat generated is relatively small. At this time, if the temperature of the battery pack in a certain area is detected to be low, the heat dissipation intensity of the area can be appropriately reduced to reduce energy waste. At the same time, according to the temperature characteristics, the charge and discharge current can be appropriately increased to improve the battery's charge and discharge efficiency and speed up the battery's charging speed.

[0079] When the SOC of the battery pack is high, the heat generated by the battery may increase. At this time, if the temperature of the battery pack in a certain area is detected to be high, it is necessary to strengthen the heat dissipation measures, such as turning on the fan or starting the liquid cooling system to reduce the battery temperature. At the same time, the charge and discharge current can be appropriately reduced to reduce the heat generated by the battery and prevent the battery from overheating.

[0080] For battery packs in poor health, their internal resistance is large and the heat generated is relatively large. At this time, if the temperature of the battery pack in a certain area is detected to be high, the temperature needs to be controlled more strictly. The charge and discharge current in this area can be greatly reduced, and a variety of heat dissipation measures can be initiated at the same time, such as turning on the fan and increasing the coolant flow of the liquid cooling system, to quickly reduce the battery temperature.

[0081] For a battery pack in good health, the heat generated is relatively small. At this time, if the temperature of the battery pack in a certain area is detected to be low, the heat dissipation intensity can be appropriately reduced to save energy. At the same time, according to the temperature characteristics, the charge and discharge current can be appropriately increased to improve the charge and discharge efficiency of the battery.

[0082] In some possible implementations, it is necessary to comprehensively consider various factors including the power requirement of the target event, the battery state of charge of the battery pack, the battery health state, and the temperature characteristics of the battery packs in each area to control the temperature of the battery packs in each area.

[0083] In industrial and commercial energy storage cabinets, when the energy storage cabinet is in the process of discharging, the power requirement is high and the temperature of the battery pack will also rise. At this time, if it is detected that the SOC of the battery pack is low, the SOH is poor, and the temperature of the battery pack in a certain area is high, the charge and discharge current in that area can be greatly reduced, and a variety of heat dissipation measures can be started at the same time, such as turning on the fan, increasing the coolant flow of the liquid cooling system, etc., to reduce the battery temperature. When the power requirement of the energy storage cabinet is reduced, the charge and discharge current and heat dissipation measures can be appropriately adjusted according to the temperature characteristics, SOC and SOH of the battery pack to keep the temperature of the battery pack within a safe range.

[0084] The temperature control method of the cable connecting the energy storage battery pack provided in the embodiment of the present invention can monitor the temperature of the energy storage system more accurately by monitoring the temperature of the cable connection, timely discover the potential danger of overheating, prevent thermal runaway, and improve safety; at the same time, based on the cable temperature and the ambient temperature, combined with the power requirements of the specific target event and the battery charge state and health state of the battery pack in each area, the charging and discharging current is accurately controlled and temperature management is achieved, thereby optimizing system performance and extending equipment life.

[0085] In some possible implementations, the temperature of the battery packs in each area is controlled based on the power requirement of the target event, the battery state of charge of the battery pack, the battery health status, and the temperature characteristics of the battery packs in each area, including: determining the lower limit value of the current at the connection between the battery packs in each area and the connecting cable based on the power requirement of the target event, the battery state of charge of the battery pack, and the battery health status; determining the upper limit value of the temperature at the connection between the battery packs in each area and the connecting cable based on the temperature characteristics of the battery packs in each area; adjusting the current at the connection between the battery packs in each area and the connecting cable and the thermal management measures of the battery packs in each area to control the temperature of the battery packs in each area based on the lower limit value of the current at the connection between the battery packs in each area and the connecting cable and the upper limit value of the temperature at the connection between the battery packs in each area and the connecting cable.

[0086] In one example, the power requirement is taken into consideration, and the minimum power that the battery packs in each area need to provide is determined based on the power demand of the target event for the energy storage system, thereby calculating the lower limit of the current of the connecting cable.

[0087] As another example, consider the battery state of charge (SOC), which affects its charge and discharge capabilities. When determining the lower current limit, it is necessary to ensure that the battery pack will not be damaged by over-discharge or over-charge while meeting the power requirements.

[0088] In another example, consider the battery health state (SOH). The battery health state affects its charging and discharging efficiency and safety. For battery packs with poor health, the current lower limit value needs to be appropriately reduced to avoid excessive current causing further damage to the battery.

[0089] In another example, by monitoring the temperature of the battery packs in each area, the peak temperature characteristics and cumulative temperature characteristics are identified. The peak temperature characteristics reflect the highest temperature value in a short period of time, while the cumulative temperature characteristics reflect the heat accumulation over a long period of time.

[0090] In another example, the upper temperature limit of the connection between the battery pack and the connecting cable in each area can also be determined according to the type of battery pack, temperature sensitivity and safety operation requirements. For example, for areas with poor heat dissipation conditions, the upper temperature limit can be set lower to prevent overheating.

[0091] On this basis, the determined current lower limit and temperature upper limit are used as control targets to monitor the current and temperature at the connection point between the battery pack and the connecting cable in each area in real time. If the current is lower than the lower limit, the current can be appropriately increased to meet the power requirements of the target event; if the temperature exceeds the upper limit, the charge and discharge current can be reduced to reduce the heat generated at the cable connection.

[0092] According to the temperature conditions, take corresponding thermal management measures, such as starting the cooling fan in the corresponding area, increasing the coolant flow of the liquid cooling system, turning on the phase change material cooling system, etc., to control the temperature of the battery pack.

[0093] It can be understood that by comprehensively considering the power requirements of the target event, the battery state of charge of the battery pack, the battery health status, and the temperature characteristics of the battery pack in each area, the temperature of the battery pack in each area is precisely controlled. It can ensure that the energy storage system meets the power requirements while avoiding overheating of the battery pack and connecting cables, improve the safety and reliability of the system, extend the life of the equipment, and optimize the system performance.

[0094] In some possible implementations, based on the power requirement of the target event, the battery state of charge and the battery health status of the battery pack, the lower limit value of the current at the connection between the battery pack in each area and the connecting cable is determined, including steps 210, 220 and 230.

[0095] Step 210, determining the minimum power that the energy storage system needs to provide based on the power requirement of the target event;

[0096] Step 220, determining a current range output by the battery pack in a current state based on a battery state of charge and a battery health state of the battery pack;

[0097] Step 230 , determining a lower limit value of the current at the connection between the battery pack and the connection cable based on the current range output from the battery pack for the minimum power that the energy storage system needs to provide.

[0098] Based on the power demand of the target event for the energy storage system, determining the minimum power that the energy storage system needs to provide can ensure that the energy storage system can meet the power requirements of the target event and is the basis for determining the lower limit of the current.

[0099] Consider the battery pack's battery state of charge (SOC) and battery state of health (SOH) to determine the current range that the battery pack can safely and stably output in the current state. The battery's SOC and SOH will affect its charge and discharge performance, so the battery pack's output current range needs to be determined based on these states to ensure that the battery pack operates within a safe range.

[0100] On this basis, combined with the minimum power that the energy storage system needs to provide and the current range that the battery pack can output, the lower limit of the current at the connection between the battery pack and the connecting cable is determined. This can ensure that while meeting the target event power requirements, the output current of the battery pack will not be lower than the minimum requirement for safe operation, thereby ensuring the safe and stable operation of the energy storage system.

[0101] In some possible implementations, the upper temperature limit of the connection between the battery packs in each area and the connecting cables is determined based on the temperature characteristics of the battery packs in each area, including: identifying the heat dissipation capacity of each area based on the temperature characteristics of the battery packs in each area; and determining the upper temperature limit of the connection between the battery packs in each area and the connecting cables based on the heat dissipation capacity of each area.

[0102] For example, the heat dissipation capacity of each region can be identified by analyzing the temperature characteristics of the battery packs in each region. The temperature characteristics include peak temperature characteristics and cumulative temperature characteristics, which reflect the temperature changes of the battery pack during operation.

[0103] Heat dissipation capacity refers to the efficiency of heat dissipation in different areas of the battery pack, which is affected by many factors, such as the structural design of the battery pack, material properties, ambient temperature, etc. For example, the battery pack in some areas has a strong heat dissipation capacity due to reasonable heat dissipation channel design and good thermal conductivity of heat dissipation materials; while other areas may have a weak heat dissipation capacity due to poor heat dissipation conditions.

[0104] In one example, at the peak temperature, the heat generated by the battery pack is Q1, and the heat that the heat dissipation system can dissipate per unit time is Q2. According to the principle of thermal balance, when the heat dissipation system can dissipate the heat generated by the battery pack in time, the temperature of the battery pack will remain stable.

[0105] Among them, Q1 can be calculated by the heat generation rate and peak temperature duration of the battery pack, and Q2 reflects the heat dissipation capacity of the cooling system.

[0106] Assume that in a period of time, the total heat generated by the battery pack is Q3, and the total heat dissipated by the cooling system is Q4. Q3 can be calculated by the heat generation rate and operating time of the battery pack, and Q4 reflects the total heat dissipation capacity of the cooling system during that period of time.

[0107] The above Q2 and Q4 can be used as indicators of heat dissipation capacity. The larger the Q2, the more heat the cooling system can dissipate per unit time and the stronger the heat dissipation capacity; the larger the Q4, the more heat the cooling system can dissipate during long-term operation and the stronger the heat dissipation capacity.

[0108] The heat dissipation capacity can be divided into different levels according to the size of Q2 and Q4. For example, when Q2 is greater than a certain threshold, the heat dissipation capacity can be rated as excellent; when Q4 is greater than a certain threshold, the heat dissipation capacity can be rated as good. By dividing the heat dissipation capacity into different levels, the heat dissipation performance of the battery pack in each area can be more intuitively evaluated, providing a basis for subsequent temperature control.

[0109] On this basis, based on the heat dissipation capacity of each area, the upper temperature limit of the connection between the battery pack and the connecting cable in each area is determined. For areas with strong heat dissipation capacity, the upper temperature limit can be appropriately increased to fully utilize its heat dissipation advantages and improve the operating efficiency of the battery pack; while for areas with weak heat dissipation capacity, the upper temperature limit needs to be lowered to prevent safety problems caused by overheating. For example, for areas with strong heat dissipation capacity, the upper temperature limit can be set to 50°C; and for areas with weak heat dissipation capacity, the upper temperature limit can be set to 40°C.

[0110] The temperature control device of the cable connecting the energy storage battery pack provided by the present invention is described below. The temperature control device of the cable connecting the energy storage battery pack described below and the temperature control method of the cable connecting the energy storage battery pack described above can correspond to each other.

[0111] like Figure 3 As shown, the temperature control device for a cable connecting an energy storage battery pack according to an embodiment of the present invention mainly includes an acquisition module 310, a first processing module 320 and a second processing module.

[0112] The acquisition module 310 is used to acquire the temperature of each cable through the temperature-sensitive element at the connection between the battery pack in each area and the connecting cable, and acquire the ambient temperature of each battery pack in each area through the ambient temperature sensor under the target event;

[0113] The first processing module 320 is used to identify the temperature characteristics of the battery packs in each area of ​​the energy storage system based on the temperature of each cable and each ambient temperature; the temperature characteristics include peak temperature characteristics and cumulative temperature characteristics;

[0114] The second processing module 330 is used to control the temperature of the battery packs in each area based on the power requirement of the target event, the battery state of charge of the battery pack, the battery health state, and the temperature characteristics of the battery packs in each area.

[0115] An embodiment of the present invention further provides a cable, comprising a temperature signal line, wherein each signal acquisition terminal of the temperature signal line is respectively connected to a temperature sensitive element at a connection point between each regional battery pack and a connecting cable in the temperature control method of a cable connecting an energy storage battery pack.

[0116] The cable of the embodiment of the present application not only has the traditional power transmission function, but also integrates the temperature monitoring function. By adding a temperature signal line to the cable, the temperature information of the connection point between the battery pack in each area and the connecting cable can be transmitted in real time.

[0117] The function of the temperature signal line is to transmit the temperature signal of the connection point between the battery pack and the connecting cable in each area to the control system. These signal acquisition terminals are connected to the temperature sensitive element and can accurately reflect the temperature change of the connection point.

[0118] Thermosensitive elements are temperature sensors installed at the connection points between the battery packs and the connecting cables in each area, which are used to monitor the temperature of the connection points in real time. These thermosensitive elements convert temperature signals into electrical signals and transmit them to the control system through the temperature signal line.

[0119] In the temperature control method of the cable connecting the energy storage battery pack in the above embodiment, by collecting the temperature signal of the connection between the battery pack in each area and the connecting cable, the temperature change of the connection can be understood in real time. These temperature signals are transmitted to the control system through the temperature signal line. The control system analyzes the temperature characteristics, identifies the heat dissipation capacity of each area, and determines the upper limit of the temperature at the connection between the battery pack in each area and the connecting cable accordingly.

[0120] Figure 4 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 4 As shown, the electronic device may include: a processor 410, a communication interface 420, a memory 430 and a communication bus 440, wherein the processor 410, the communication interface 420 and the memory 430 communicate with each other through the communication bus 440. The processor 410 may call the logic instructions in the memory 430 to execute the temperature control method of the cable connecting the energy storage battery pack, the method comprising: under the target event, obtaining the temperature of each cable through the temperature-sensitive element at the connection between the battery pack in each region and the connecting cable, and obtaining the ambient temperature of each battery pack in each region through the ambient temperature sensor; based on the temperature of each cable and the ambient temperature, identifying the temperature characteristics of the battery pack in each region of the energy storage system; the temperature characteristics include peak temperature characteristics and cumulative temperature characteristics; based on the power requirement of the target event, the battery state of charge of the battery pack, the battery health status and the temperature characteristics of the battery pack in each region, controlling the temperature of the battery pack in each region.

[0121] In addition, the logic instructions in the above-mentioned memory 430 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0122] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the temperature control method of the cable connecting the energy storage battery pack provided by the above methods, the method including: under a target event, obtaining the temperature of each cable through a temperature-sensitive element at the connection between the battery pack in each area and the connecting cable, and obtaining the ambient temperature of each battery pack in each area through an ambient temperature sensor; based on the temperature of each cable and the ambient temperature, identifying the temperature characteristics of the battery pack in each area of ​​the energy storage system; the temperature characteristics include peak temperature characteristics and cumulative temperature characteristics; based on the power requirement of the target event, the battery state of charge of the battery pack, the battery health status and the temperature characteristics of the battery pack in each area, controlling the temperature of the battery pack in each area.

[0123] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the temperature control method of the cable connecting the energy storage battery pack provided by the above-mentioned methods, the method comprising: under a target event, obtaining the temperature of each cable through a temperature-sensitive element at a connection between the battery pack in each area and the connecting cable, and obtaining the ambient temperature of each battery pack in each area through an ambient temperature sensor; based on the temperature of each cable and the ambient temperature, identifying the temperature characteristics of the battery pack in each area of ​​the energy storage system; the temperature characteristics include peak temperature characteristics and cumulative temperature characteristics; based on the power requirement of the target event, the battery state of charge of the battery pack, the battery health status and the temperature characteristics of the battery pack in each area, controlling the temperature of the battery pack in each area.

[0124] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0125] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A temperature control method for a cable connecting an energy storage battery pack, characterized in that: include: Under the target event, the temperature of each cable is obtained through the temperature-sensitive element at the connection between the battery pack in each area and the connecting cable, and the ambient temperature of each battery pack in each area is obtained through the ambient temperature sensor; Based on the temperature of each cable and each ambient temperature, identifying the temperature characteristics of the battery packs in each area of ​​the energy storage system; the temperature characteristics include peak temperature characteristics and cumulative temperature characteristics; Based on the power requirement of the target event, the battery state of charge of the battery pack, the battery health state, and the temperature characteristics of the battery packs in each area, determine the upper current limit and the lower current limit at the connection between the battery packs in each area and the connection cable, and control the temperature of the battery packs in each area; Controlling the temperature of the battery packs in each area includes: formulating a temperature control strategy based on the power requirements of the target event; the temperature control strategy includes: reducing the charge and discharge current of the area and starting heat dissipation measures when the peak temperature of the area is detected to be too high; starting heat dissipation measures and adjusting the charge and discharge mode when the accumulated heat in the area reaches the control upper limit; adjusting the charge and discharge mode includes: reducing the charge and discharge rate, increasing the rest time, and limiting the charge and discharge depth of the area; limiting the charge and discharge depth of the area includes narrowing the range of battery charge state; The peak temperature characteristic is used to represent the maximum value between the cable temperature and the ambient temperature; the cumulative temperature characteristic is used to represent the cumulative heat load caused by continuous heating; the cumulative temperature characteristic Q is expressed as: ； Among them, t1 and t2 represent the starting and ending time of the cumulative time period respectively, T conn is the junction temperature, T env is the ambient temperature.

2. The temperature control method of the cable connecting the energy storage battery pack according to claim 1, characterized in that: The method of determining the upper current limit and the lower current limit at the connection between the battery pack in each area and the connecting cable based on the power requirement of the target event, the battery state of charge of the battery pack, the battery health state, and the temperature characteristics of the battery pack in each area, and controlling the temperature of the battery pack in each area includes: Based on the power requirement of the target event, the battery state of charge and the battery health state of the battery pack, determine the lower limit value of the current at the connection between the battery pack in each area and the connecting cable; based on the temperature characteristics of the battery pack in each area, determine the upper limit value of the temperature at the connection between the battery pack in each area and the connecting cable; Based on the lower current limit value at the connection between the battery packs in each area and the connecting cables and the upper temperature limit value at the connection between the battery packs in each area and the connecting cables, the current at the connection between the battery packs in each area and the connecting cables and the thermal management measures of the battery packs in each area are adjusted to control the temperature of the battery packs in each area.

3. The temperature control method of the cable connecting the energy storage battery pack according to claim 2, characterized in that: The determining of the lower limit value of the current at the connection between the battery pack in each area and the connection cable based on the power requirement of the target event, the battery state of charge and the battery health state of the battery pack includes: Based on the power requirement of the target event, determining the minimum power that the energy storage system needs to provide; Determining a current range output by the battery pack in a current state based on a battery state of charge and a battery health state of the battery pack; The lower limit value of the current at the connection between the battery pack and the connecting cable is determined based on the current range output from the battery pack for the minimum power that the energy storage system needs to provide.

4. The temperature control method of the cable connecting the energy storage battery pack according to claim 2, characterized in that: The determining of the upper temperature limit of the connection between the battery packs in each area and the connection cable based on the temperature characteristics of the battery packs in each area includes: Based on the temperature characteristics of the battery packs in each area, identify the heat dissipation capacity of each area; Based on the heat dissipation capacity of each area, the upper temperature limit of the connection point between the battery pack and the connection cable in each area is determined.

5. The temperature control method of the cable connecting the energy storage battery pack according to claim 1, characterized in that: The target event includes at least one of a power grid frequency regulation event, a peak shaving and valley filling event, and an energy grid connection event.

6. A cable, characterized in that: It comprises a temperature signal line, and each signal acquisition terminal of the temperature signal line is respectively connected to the temperature sensitive element at the connection between each regional battery pack and the connecting cable in the temperature control method of the cable connecting the energy storage battery pack according to any one of claims 1 to 5.

7. A temperature control device for a cable connecting an energy storage battery pack, characterized in that: The device uses the temperature control method of the cable connecting the energy storage battery pack as claimed in any one of claims 1 to 5 to control the temperature of the battery packs in each area of ​​the energy storage system, and the device includes: An acquisition module is used to acquire the temperature of each cable through a temperature-sensitive element at a connection point between a battery pack in each area and a connecting cable under a target event, and to acquire the ambient temperature of each battery pack in each area through an ambient temperature sensor; A first processing module, for identifying temperature characteristics of battery packs in each area of ​​the energy storage system based on the temperature of each cable and each ambient temperature; the temperature characteristics include peak temperature characteristics and cumulative temperature characteristics; The second processing module is used to determine the upper and lower current limits at the connection between the battery packs in each area and the connecting cables based on the power requirement of the target event, the battery state of charge, the battery health status of the battery pack, and the temperature characteristics of the battery packs in each area, so as to control the temperature of the battery packs in each area.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that: When the processor executes the program, the temperature control method of the cable connecting the energy storage battery pack as described in any one of claims 1 to 5 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the temperature control method of the cable connected to the energy storage battery pack as claimed in any one of claims 1 to 5 is implemented.

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