Battery temperature control method and device and electronic equipment

Abstract

The invention provides a battery temperature control method and device and electronic equipment, and the method comprises the steps: carrying out the temperature detection of a battery and a working environment where the battery is located when a refrigerant channel is in an open state, and determining a battery temperature change stability coefficient; a resistance value and a current value of a first resistor in the temperature detection circuit are detected, and a circuit environment resistance deviation coefficient and a circuit output power stability coefficient are determined; and according to the battery temperature change stability coefficient, the circuit environment resistance deviation coefficient and the circuit output power stability coefficient, an accurate coefficient used for adjusting the closing time of the refrigerant channel is determined. By comprehensively considering multiple factors such as battery temperature change, circuit environment resistance deviation and circuit output power stability, the accurate coefficient for adjusting the closing time of the refrigerant channel is determined, the temperature of the battery system can be more accurately controlled, the cycle index and the performance retention rate of the battery are further improved, and the service life of the battery system is prolonged. And long-term stable use of the battery is guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of battery management, and particularly to a battery temperature control method, device and electronic device. Background Art

[0002] A Battery Management System (BMS), commonly known as a battery nanny or battery steward, can monitor the state of a battery in real time, accurately grasp the battery health, achieve intelligent management of the battery and maintenance of each battery unit, prevent the battery from overcharging or discharging, and extend the service life of the battery. When the battery temperature is too high, the BMS can cool the battery through a refrigerant pipeline to maintain the good performance of the battery. However, when the battery management system issues an exit cooling instruction, the residual refrigerant in the refrigerant channel continues to cool the battery, resulting in a continuous drop in the battery temperature, which has a negative impact on the battery service life and safety performance. Currently, the refrigerant channel cannot be started and closed in a timely manner, and the start and stop times cannot be accurately monitored and adjusted based on the battery temperature value, which will interfere with the normal use of the battery. Summary of the Invention

[0003] Embodiments of the present application provide a battery temperature control method, device and electronic device, so as to solve the technical problem that when the battery management system issues an exit cooling instruction, the residual refrigerant in the refrigerant channel continues to cool the battery, causing the battery temperature to continuously drop, affecting the service life and safety performance of the battery.

[0004] In a first aspect, an embodiment of the present application provides a battery temperature control method, the method includes:

[0005] When the refrigerant channel in the battery system is in an open state, detect the temperature of the battery and the working environment where the battery is located in the battery system, obtain the battery temperature and the working environment temperature, and determine a battery temperature change stability coefficient according to the battery temperature and the working environment temperature; wherein, the battery temperature is detected by a temperature detection circuit;

[0006] Detect the resistance value and current value of a first resistor in the temperature detection circuit, obtain the resistance value and current value, and determine a circuit environment resistance deviation coefficient and a circuit output power stability coefficient according to the resistance value and the current value; wherein, the temperature detection circuit includes a first operational amplifier, a second operational amplifier and a first resistor, and the first resistor is connected between the output end of the first operational amplifier and the input end of the second operational amplifier;

[0007] Determine an accuracy coefficient according to the battery temperature change stability coefficient, the circuit environment resistance deviation coefficient and the circuit output power stability coefficient;

[0008] Adjust the closing time of the refrigerant channel according to the accuracy coefficient to control the temperature of the battery in the battery system.

[0009] In a second aspect, an embodiment of the present application further provides a battery temperature control device, which includes:

[0010] A first determination module, configured to detect the temperature of the battery and the working environment where the battery is located in the battery system when the refrigerant channel in the battery system is in an open state, obtain the battery temperature and the working environment temperature, and determine a battery temperature change stability coefficient according to the battery temperature and the working environment temperature; wherein, the battery temperature is detected by a temperature detection circuit;

[0011] A second determination module, configured to detect the resistance value and the current value of a first resistor in the temperature detection circuit, obtain the resistance value and the current value, and determine a circuit environment resistance deviation coefficient and a circuit output power stability coefficient according to the resistance value and the current value; wherein, the temperature detection circuit includes a first operational amplifier, a second operational amplifier and a first resistor, and the first resistor is connected between the output end of the first operational amplifier and the input end of the second operational amplifier;

[0012] A third determination module, configured to determine an accuracy coefficient according to the battery temperature change stability coefficient, the circuit environment resistance deviation coefficient and the circuit output power stability coefficient;

[0013] An adjustment module, configured to adjust the closing time of the refrigerant channel according to the accuracy coefficient to control the temperature of the battery in the battery system.

[0014] In a third aspect, an embodiment of the present application further provides an electronic device, which includes a processor, a memory, and a computer program stored on the memory and executable on the processor. When the computer program is executed by the processor, the above-mentioned battery temperature control method is implemented.

[0015] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the above-mentioned battery temperature control method is implemented.

[0016] The embodiments of the present application at least include the following technical effects:

[0017] The technical solution of the embodiment of the present application collects various working data of the battery system when the refrigerant channel in the battery system is in an open state, and determines a battery temperature change stability coefficient indicating whether the battery temperature fluctuation is within a safe range according to the battery temperature and the working environment temperature in the working data. At the same time, according to the resistance value and current value of the first resistor in the working data, a circuit environment resistance deviation coefficient indicating whether the resistance change exceeds the expected range and a circuit output power stability coefficient indicating the power transmission efficiency and stability are determined. Then, an accuracy coefficient is determined according to the above coefficients, so that the accuracy coefficient comprehensively considers multiple factors such as battery temperature change, circuit environment resistance deviation, and circuit output power stability. And the closing time of the refrigerant channel is adjusted according to the accuracy coefficient to control the battery temperature in the battery system. The present application can avoid the problem that when the battery management system issues an instruction to exit cooling, the residual refrigerant in the refrigerant channel continues to cool the battery, causing the battery temperature to continue to drop, affecting the service life and safety performance of the battery, thereby increasing the cycle times and performance retention rate of the battery, and providing guarantee for the long-term stable use of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art.

[0019] Figure 1 is a schematic flowchart of the battery temperature control method provided by the embodiment of the present application;

[0020] Figure 2 is a schematic structural diagram of the temperature detection circuit provided by the embodiment of the present application;

[0021] Figure 3 is a schematic structural diagram of the battery temperature control device provided by the embodiment of the present application;

[0022] Figure 4 is a block diagram of the electronic device provided by the embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0024] It should be understood that the "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the "in one embodiment" or "in an embodiment" that appears throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner.

[0025] In various embodiments of the present application, it should be understood that the magnitude of the sequence numbers of the following processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0026] As Figure 1 shown, the embodiment of the present application provides a battery temperature control method, which includes:

[0027] Step 101, when the refrigerant channel in the battery system is in an open state, detect the temperature of the battery in the battery system and the working environment where the battery is located, obtain the battery temperature and the working environment temperature, and determine the battery temperature change stability coefficient according to the battery temperature and the working environment temperature; wherein, the battery temperature is detected by a temperature detection circuit.

[0028] The battery temperature control method provided by the embodiment of the present application is applied to the battery management system corresponding to the battery system. The batteries in the battery system can be various types of batteries, such as lithium-ion batteries, lead-acid batteries, nickel-metal hydride batteries, etc. Exemplarily, in an electric vehicle, the battery system is one of the core components, and its performance and safety directly affect the driving range and reliability of the vehicle. Through the battery temperature control method provided by the embodiment of the present application, the temperature management ability of the electric vehicle battery can be effectively improved, the battery performance degradation and safety hazards caused by temperature problems can be reduced, and the overall performance and user experience of the electric vehicle can be improved.

[0029] Specifically, when the battery system is in a working state, the battery temperature in the battery system will be continuously monitored. When the battery temperature is higher than the preset temperature threshold, the refrigerant channel will be opened to cool the battery. Since the performance and life of the battery are closely related to temperature, and different working environment temperatures will also affect the heat dissipation of the battery, in the embodiment of the present application, when the refrigerant channel in the battery system is in an open state, the temperature of the battery itself and the working environment where the battery is located is detected in real time. Exemplarily, the battery temperature and the working environment temperature data can be continuously collected, and the collection time can be set according to actual needs. For example, it can be collected once every unit time, and the unit time can be one minute or half a minute. The present application does not make specific limitations on this.

[0030] Among them, the battery temperature can be detected by a temperature detection circuit. The temperature detection circuit works based on the characteristic that the resistance of a conductor changes with temperature. When the battery temperature changes, the resistance value of the thermistor changes accordingly. By measuring the voltage or current change caused by this resistance change, and then amplifying and processing the signal through circuit elements such as operational amplifiers, an electrical signal corresponding to the battery temperature is finally obtained, which is the battery temperature value after conversion. The working environment temperature can be detected by a temperature sensor. The temperature sensor can convert the ambient temperature into an electrical signal output, and then the specific value of the ambient temperature can be obtained.

[0031] By continuously monitoring and analyzing the battery temperature and the working environment temperature, the battery temperature change stability coefficient is determined. This battery temperature change stability coefficient reflects the stability of the battery temperature in the state where the refrigerant channel is open.

[0032] Step 102: Detect the resistance value and current value of the first resistor in the temperature detection circuit, obtain the resistance value and current value, and determine the circuit environment resistance deviation coefficient and the circuit output power stability coefficient according to the resistance value and the current value; wherein, the temperature detection circuit includes a first operational amplifier, a second operational amplifier, and a first resistor, and the first resistor is connected between the output end of the first operational amplifier and the input end of the second operational amplifier.

[0033] As Figure 2 shown, the temperature detection circuit includes a first operational amplifier A1, a second operational amplifier A2, and a first resistor R1. The first resistor R1 is connected between the output end of the first operational amplifier A1 and the input end of the second operational amplifier A2, playing an important role in signal transmission and regulation. This temperature detection circuit also includes a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a variable resistor RT. Among them, the variable resistor RT is connected to the power supply and grounded for protection. The variable resistor RT is connected in parallel to the first operational amplifier A1 at the non-inverting input terminal. The output end of the first operational amplifier A1 is connected in series with the parallel-connected second operational amplifier A2 and the second resistor R2 through the resistor R1. The non-inverting input terminal and the inverting input terminal of the second operational amplifier A2 are respectively connected to the third resistor R3 and the grounded fourth resistor R4, and the output end of the second operational amplifier A2 is connected to the non-inverting input terminal of the first operational amplifier A1 through the parallel-connected fifth resistor R5. A follower is formed between the first operational amplifier A1 and the circuit, and an amplifier is formed between the second amplifier A2 and the circuit. A signal input terminal and a signal output terminal are also connected to both ends of the variable resistor RT.

[0034] In the temperature detection circuit, the characteristic that the resistance value of a conductor changes with temperature is utilized to measure temperature. By adopting a low-offset, low-power consumption, high-precision dual-channel operational amplifier and designing it into a corresponding adder and follower, the signal is amplified and processed, and a high input impedance and a low output impedance can be provided, thereby effectively isolating the input and output circuits and ensuring the accuracy of the signal phase retention.

[0035] In the battery management system, the resistance value of the resistance sensor is converted into a voltage value that is easy to measure. After being amplified and processed by the temperature monitoring circuit signal, it is transmitted to the A / D converter for analog-to-digital conversion, thereby converting the detected voltage signal into a digital signal, that is, the corresponding temperature value, and then transmitting the temperature of the battery in the circuit to the battery management system for feedback display.

[0036] In the temperature detection circuit, the upper and lower voltages of the fifth resistor R5 are the output voltage of the adder. The follower formed between the first operational amplifier A1 connected to the power supply and the circuit can receive high-impedance signals without causing signal attenuation, and can also provide a lower output impedance to adapt to the circuit load. At the same time, this follower maintains the invariance of the phase signal by providing an output identical to the input signal, which is particularly important for accurately retaining the phase information of the signal, so as to stably and accurately output the phase signal of the voltage without change.

[0037] In addition, the variable resistor RT connected to the input and output signal terminals can limit the magnitude of the current in the circuit by changing the resistance value, thereby preventing damage to electrical components caused by excessive current in the circuit. At the same time, by setting the resistance at multiple points, on the one hand, it can play a role in circuit protection, and on the other hand, by measuring the voltage at multiple points, the voltage change of this branch can be understood, and the temperature change data can be obtained through the feedback of the voltage change signal.

[0038] In the embodiment of the present application, a resistance measuring instrument, such as a multimeter, can be used to detect the resistance value and current value of the first resistor, so as to further understand the working state of the circuit.

[0039] Specifically, according to the detected resistance value of the first resistor, the circuit environment resistance deviation coefficient can be determined. This coefficient reflects the stability of the resistance parameters in the circuit, and the deviation of the resistance may affect the accuracy and reliability of the temperature detection circuit. At the same time, according to the detected current value and resistance value of the first resistor, the circuit output power stability coefficient is determined. This coefficient reflects the fluctuation of the circuit output power, and the instability of the power may lead to inaccurate temperature detection and affect the control of the battery temperature.

[0040] Step 103: Determine the precision coefficient according to the battery temperature change stability coefficient, the circuit environment resistance deviation coefficient, and the circuit output power stability coefficient.

[0041] After obtaining the battery temperature change stability coefficient, the circuit environment resistance deviation coefficient, and the circuit output power stability coefficient, considering that these three coefficients reflect the working state and stability of the battery system from different aspects, the embodiment of the present application combines them to determine the precise coefficient, so that the accuracy of the entire system can be evaluated more comprehensively and accurately. Specifically, through a preset calculation method, these three coefficients are integrated to obtain a precise coefficient, which can serve as an important basis for subsequent adjustment of the refrigerant channel closing time.

[0042] Step 104: According to the precision coefficient, adjust the closing time of the refrigerant channel to control the temperature of the battery in the battery system.

[0043] After obtaining the precision coefficient, the closing time of the refrigerant channel can be adjusted according to the size of the precision coefficient. Specifically, when the precision coefficient is in different ranges, it indicates that the working state and temperature control of the battery system are different, and different control strategies need to be adopted. For example, when the precision coefficient indicates that the battery temperature changes are unstable, the circuit parameter deviation is large, or the output power fluctuates significantly, the opening time of the refrigerant channel is appropriately extended to enhance heat dissipation to ensure that the battery operates within a suitable temperature range; conversely, if the precision coefficient shows that the system operates stably, the refrigerant channel can be closed at a normal time.

[0044] Exemplarily, a preset range can be set in advance, for example, the preset range can be 0.03 to 0.07. When the precision coefficient is not within the preset range and is less than 0.03, it indicates that the battery temperature change is unstable, the circuit parameter deviation is large, or the output power fluctuates significantly. At this time, the opening time of the refrigerant channel can be appropriately extended to enhance heat dissipation to ensure that the battery operates within a suitable temperature range. For example, the time originally planned to close the refrigerant channel is postponed by 1 minute. When the precision coefficient is within the preset range, that is, between 0.03 and 0.07, it indicates that the system working state is relatively stable, and the refrigerant channel can be closed at a normal time to maintain the current temperature control strategy. When the precision coefficient is not within the preset range and is greater than 0.07, it indicates that the battery temperature change is stable, the circuit parameters are stable, and the output power fluctuation is small. At this time, the refrigerant channel can be closed in advance to reduce energy consumption. For example, the time originally planned to close the refrigerant channel is advanced by 2 minutes.

[0045] In the embodiment of the present application, when the refrigerant channel in the battery system is in the open state, various operating data of the battery system are collected, and according to the battery temperature and the operating environment temperature in the operating data, a battery temperature change stability coefficient indicating whether the battery temperature fluctuation is within the safe range is determined. At the same time, according to the resistance value and the current value of the first resistor in the operating data, a circuit environment resistance deviation coefficient indicating whether the resistance change exceeds the expected range and a circuit output power stability coefficient indicating the power transmission efficiency and stability are determined. Then, an accuracy coefficient is determined based on the above coefficients, so that the accuracy coefficient comprehensively considers multiple factors such as battery temperature change, circuit environment resistance deviation, and circuit output power stability. And the closing time of the refrigerant channel is adjusted according to the accuracy coefficient to control the battery temperature in the battery system. The present application can avoid the problem that when the battery management system issues an exit cooling instruction, the residual refrigerant in the refrigerant channel continues to cool the battery, causing the battery temperature to continue to drop, affecting the service life and safety performance of the battery, thereby increasing the number of battery cycles and the performance retention rate, and providing guarantee for the long-term stable use of the battery.

[0046] In an alternative embodiment of the present application, determining the battery temperature change stability coefficient according to the battery temperature and the operating environment temperature includes:

[0047] According to the battery temperature and the operating environment temperature, determine the initial battery temperature, the current battery temperature corresponding to the current acquisition time point, and the current operating environment temperature; wherein, the preset time interval is set between adjacent acquisition time points;

[0048] Calculate the absolute value of the difference between the current battery temperature and the current operating environment temperature to obtain the current temperature difference corresponding to the current acquisition time point;

[0049] Calculate the absolute value of the difference between the current temperature difference and the initial battery temperature to obtain the absolute value of the temperature change;

[0050] According to the initial battery temperature, the preset temperature rise rate, and the target duration, determine the preset value of the temperature change; wherein, the target duration is the time interval between the current acquisition time point and the initial acquisition time point;

[0051] Calculate the absolute value of the difference between the absolute value of the temperature change and the preset value of the temperature change to obtain the first parameter;

[0052] Calculate the sum of the absolute value of the temperature change and the preset value of the temperature change to obtain the second parameter;

[0053] Calculate the product of the ratio of the first parameter to the second parameter and the preset duration to obtain the battery temperature change stability coefficient.

[0054] When determining the battery temperature change stability coefficient, first, based on the battery temperature and the working environment temperature, determine the initial battery temperature, the current battery temperature corresponding to the current acquisition time point, and the current working environment temperature. The interval between adjacent acquisition time points is a preset duration, which is set according to the characteristics of the battery system and the accuracy requirements for temperature change detection. For example, in an electric vehicle battery system, since the temperature changes relatively quickly during battery operation, the preset duration can be set shorter, such as 10 seconds. While in some energy storage battery systems, the temperature changes relatively slowly, and the preset duration can be set longer, such as 1 minute, etc.

[0055] After obtaining the current battery temperature and the current working environment temperature corresponding to the current acquisition time point, calculate the absolute value of the difference between the current battery temperature and the current working environment temperature to obtain the current temperature difference corresponding to the current acquisition time point. This current temperature difference characterizes the degree of temperature difference between the battery and the surrounding environment at the current acquisition time point. The performance of the battery is closely related to this temperature difference. A larger temperature difference may mean that there is an abnormality in the heat dissipation or heat generation of the battery. For example, in the normal working state, the temperature difference between the battery and the environment should fluctuate within a certain range. If the current temperature difference suddenly increases, it may indicate that the internal chemical reaction of the battery intensifies, resulting in increased heat generation, or there is a malfunction in the heat dissipation system.

[0056] Then, calculate the absolute value of the difference between the current temperature difference and the initial battery temperature to obtain the absolute value of temperature change. This absolute value of temperature change reflects the deviation of the temperature difference between the battery and the environment from the initial battery temperature from the initial state to the current acquisition time point. Based on the initial temperature, it can be more intuitive to see the severity of the temperature change of the battery during the entire working process. For example, if the initial battery temperature is 25°C, the initial temperature difference between the battery and the environment is 5°C, and the current temperature difference between the battery and the environment becomes 15°C, then the absolute value of temperature change is 10°C.

[0057] The embodiment of the present application also determines a preset value of temperature change according to the initial battery temperature, the preset temperature rise rate, and the target duration. The preset temperature rise rate is a reference value determined based on the type of battery, material characteristics, and historical experimental data, etc. It represents the amplitude of the battery temperature that should rise or fall per unit time under normal working conditions. The target duration is the interval duration between the current acquisition time point and the initial acquisition time point. Through the formula: preset value of temperature change = initial battery temperature × preset temperature rise rate × target duration, the amplitude of the battery temperature that should change theoretically during this period can be obtained. For example, the initial battery temperature is 20°C, the preset temperature rise rate is 0.1°C / minute, and the target duration is 30 minutes, then the preset value of temperature change = 20×0.1×30 = 60°C.

[0058] After obtaining the absolute value of the temperature change and the preset value of the temperature change, calculate the absolute value of the difference between the absolute value of the temperature change and the preset value of the temperature change to obtain the first parameter. At the same time, calculate the sum of the absolute value of the temperature change and the preset value of the temperature change to obtain the second parameter. Among them, the first parameter reflects the deviation degree between the actual temperature change and the theoretical expected temperature change. The smaller the value of the first parameter, the closer the actual temperature change is to the theoretical value, and the more stable the battery working state is. The second parameter comprehensively considers the actual temperature change situation and the theoretically expected temperature change situation, and reflects the overall amplitude of the battery temperature change. The larger the value of the second parameter, the wider the range of the battery temperature change, indicating that both the actual change and the theoretical expected change are larger; conversely, the smaller the value of the second parameter, the relatively smaller the battery temperature change.

[0059] Finally, calculate the product of the ratio of the first parameter to the second parameter and the preset duration to obtain the battery temperature change stability coefficient. This coefficient comprehensively reflects the stability of the battery temperature change by integrating the above various parameters. If the coefficient is small, it indicates that the actual temperature change is close to the theoretical expectation and the battery temperature change is stable; conversely, if the coefficient is large, it means that the battery temperature change fluctuates greatly and the stability is poor.

[0060] The calculation formula of the battery temperature change coefficient is as follows:

[0061]

[0062] Among them, wz is the battery temperature change coefficient, yc K is the absolute value of the temperature change, sc K is the preset value of the temperature change, |yc K -sc K | is the first parameter, (yc K +sc K ) is the second parameter, and S is the preset duration.

[0063] In the above implementation scheme of this application, when determining the battery temperature change stability coefficient, multiple factors such as the initial temperature of the battery, the current temperature of the battery, the current temperature of the working environment, and time are comprehensively considered, which can accurately reflect the stability of the battery temperature change. Compared with simply monitoring the battery temperature itself, this method can better capture the temperature dynamic change situation of the battery in a complex working environment, provide a more accurate basis for subsequent battery management decisions, and ensure the safe and reliable operation of the battery system.

[0064] In an optional embodiment of this application, determining the circuit environment resistance deviation coefficient includes:

[0065] For each acquisition time point, determine the ratio parameter corresponding to the acquisition time point by taking the ratio of the resistance value corresponding to the acquisition time point to the acquisition time point;

[0066] For each acquisition time point, determine the average value parameter corresponding to the acquisition time point by taking the average of the ratio parameter corresponding to the acquisition time point and the ratio parameter corresponding to the previous acquisition time point of the acquisition time point.

[0067] At the current acquisition time point, obtain the circuit environment scale factor and the maximum deviation range of the ratio between the resistance value and the time point within the target time period; wherein, the target time period is the time period between the current acquisition time point and the initial acquisition time point.

[0068] For each acquisition time point, calculate the product of the ratio of the maximum deviation range corresponding to the acquisition time point to the average value parameter and the circuit environment scale factor to obtain the resistance deviation value corresponding to each acquisition time point.

[0069] Calculate the sum of the resistance deviation values corresponding to each acquisition time point within the target time period to obtain the circuit environment resistance deviation coefficient.

[0070] In the embodiment of the present application, during the operation of the temperature detection circuit, the resistance value of the first resistor is periodically acquired at regular time intervals, and the time point information corresponding to each resistance value is recorded.

[0071] When determining the circuit environment resistance deviation coefficient, first, by dividing the resistance value corresponding to the acquisition time point by the acquisition time point, a ratio parameter that can reflect the changing trend of the resistance over time is constructed, and each acquisition time point corresponds to a ratio parameter. This ratio parameter can highlight the relative situation of the resistance change at different time points. Specifically, if the resistance value grows rapidly within a certain period of time while the time point is also advancing, the ratio parameter can intuitively reflect the relationship between the growth rate and time.

[0072] In order to smooth the fluctuation of the ratio parameter and reduce the influence of instantaneous outliers on the result, in the embodiment of the present application, after obtaining the ratio parameter corresponding to each acquisition time point, the ratio parameter corresponding to the previous acquisition time point of the acquisition time point is further obtained, and then the average of the ratio parameter corresponding to the acquisition time point and the ratio parameter corresponding to the previous acquisition time point is taken as the average value parameter of the acquisition time point. Using the average value can effectively filter out the mutation of the ratio parameter caused by some accidental factors, and obtain a more stable parameter that can represent the changing trend of the resistance value over time, making the subsequent analysis more stable and reliable.

[0073] Meanwhile, the embodiments of the present application also obtain the circuit environment proportionality factor and the maximum deviation range of the ratio between the resistance value and the time point within the target time period. The circuit environment proportionality factor is determined by circuit design parameters (such as conductor material, cross-section, etc.), and is a coefficient related to circuit characteristics, working environment, etc., which is used to adjust the deviation weight of different circuit structures and reasonably scale the final resistance deviation value to adapt to different circuit scenarios. The maximum deviation range defines the maximum fluctuation range that the ratio of the resistance value to the time may appear within the entire target time period, and can be set based on the temperature rise characteristics of the conductor.

[0074] After obtaining the circuit environment proportionality factor and the maximum deviation range, for each acquisition time point, calculate the ratio of the maximum deviation range corresponding to this acquisition time point to the average value parameter multiplied by the circuit environment proportionality factor to obtain the resistance deviation value. The calculation of the resistance deviation value comprehensively considers the trend of the resistance value changing with time, the maximum allowable fluctuation range of the ratio of the resistance value to the time, and the inherent characteristics of the circuit, thereby quantifying the deviation degree of the resistance at each acquisition time point relative to the ideal situation.

[0075] The calculation formula of the resistance deviation value is as follows:

[0076]

[0077] Wherein, X i is the resistance deviation value, L is the circuit environment proportionality factor, |pv z -pv d | is the maximum deviation range of the ratio between the resistance value and the time point within the target time period (pv z is the upper limit value, pv d is the lower limit value), wx c is the average value parameter.

[0078] Finally, accumulate the resistance deviation values corresponding to all acquisition time points within the target time period to obtain the circuit environment resistance deviation coefficient. The target time period is the time period from the initial acquisition time point to the current acquisition time point. The circuit environment resistance deviation coefficient reflects the overall deviation situation of the circuit resistance value changing with time relative to the ideal state within the entire target time period, and measures whether the resistance change exceeds the expected range. The larger the value of the circuit environment resistance deviation coefficient, the greater the resistance deviation, and the reasons may be temperature or aging, etc.

[0079] The calculation formula of the circuit environment resistance deviation coefficient is as follows:

[0080]

[0081] Wherein, Qs d is the circuit environment resistance deviation coefficient, and q is the number of acquisition time points within the target time period.

[0082] In the above implementation of the present application, by comprehensively considering the variation trend of the resistance value over time, the maximum allowable deviation range, and the inherent characteristics of the circuit, the stability of the resistor in the circuit environment can be accurately evaluated, the information behind the resistor change can be more deeply explored, whether the resistor is in a normal working state can be accurately judged, and the stability of the resistor in the circuit environment can be comprehensively evaluated, providing an important basis for evaluating the circuit performance.

[0083] In an alternative embodiment of the present application, determining the circuit output power stability coefficient according to the resistance value and the current value includes:

[0084] For each acquisition time point, according to the resistance value and the current value, calculate the difference between the input power and the output power of the temperature detection circuit at the acquisition time point to obtain a power difference;

[0085] At the current acquisition time point, obtain the temperature difference between the highest temperature and the lowest temperature detected by the temperature detection circuit, the output voltage value of the temperature detection circuit, and the conductivity coefficient of the first resistor;

[0086] At the current acquisition time point, according to the power differences corresponding to the respective acquisition time points within the target time period, calculate the sum of the squares of the power differences within the target time period to obtain a third parameter, where the target time period is the time period between the current acquisition time point and the initial acquisition time point;

[0087] At the current acquisition time point, take the square root of the ratio of the third parameter corresponding to the current acquisition point to the temperature difference corresponding to the current acquisition point to obtain a fourth parameter;

[0088] At the current acquisition point, calculate the product of the ratio of the output voltage value corresponding to the current acquisition point to the resistance value and the conductivity coefficient to obtain a fifth parameter;

[0089] Determine the sum of the fourth parameter and the fifth parameter as the circuit output power stability coefficient.

[0090] Specifically, in order to measure the loss or gain in the energy conversion process of the circuit at each acquisition time point, calculate the difference between the input power and the output power of the temperature detection circuit at each acquisition time point to obtain a power difference. The power difference can directly reflect the effectiveness of energy utilization when the circuit is operating. A smaller power difference indicates that the energy conversion process is relatively stable and the circuit output power is relatively stable; a larger power difference indicates that there are large fluctuations in the energy conversion, which may affect the stability of the circuit output power.

[0091] Meanwhile, at the current acquisition time point, obtain the temperature difference between the highest temperature and the lowest temperature detected by the temperature detection circuit, the output voltage value of the temperature detection circuit, and the conductivity of the first resistor. Among them, the temperature difference between the highest temperature and the lowest temperature detected by the temperature detection circuit is closely related to the thermal stability of the circuit. The conductivity reflects the ease with which a material allows current to pass through. The greater the conductivity, the better the electrical conductivity of the material.

[0092] By calculating the sum of squares of the power differences within the target time period, obtain the third parameter, where the target time period is the time period between the current acquisition time point and the initial acquisition time point. In the embodiments of the present application, the square sum operation amplifies the fluctuation influence of the power difference, highlighting the power fluctuation situation.

[0093] The calculation formula of the third parameter is as follows:

[0094]

[0095] Among them, C3 is the third parameter, (pu i -pu o ) is the power difference, pu i is the input power, pu o is the output power.

[0096] After obtaining the third parameter, take the square root of the ratio of the third parameter to the temperature difference, and on the basis of comprehensively considering the power fluctuation and the temperature fluctuation, obtain the fourth parameter that can reflect the influence of the relationship between the two on the output power stability.

[0097] The calculation formula of the fourth parameter is as follows:

[0098]

[0099] Among them, C4 is the third parameter, T z and T d The highest temperature and the lowest temperature detected by the temperature detection circuit (T z -T d ) is the temperature difference.

[0100] The embodiments of the present application also calculate the product of the ratio of the output voltage value to the resistance value and the conductivity to obtain the fifth parameter. This fifth parameter comprehensively considers the current in the circuit and the electrical conductivity of the material, and can more comprehensively and accurately evaluate the working state of the circuit and its influence on the output power stability.

[0101] The calculation formula of the fifth parameter is as follows: R

[0102]

[0103] Among them, C5 is the third parameter, U is the voltage value, R is the resistance value, and f is the conductivity coefficient.

[0104] After obtaining the fourth parameter and the fifth parameter, the sum of the fourth parameter and the fifth parameter is determined as the circuit output power stability coefficient, and the stability degree of the circuit output power can be comprehensively and accurately evaluated by a multi-factor comprehensive method.

[0105] The calculation formula of the circuit output power stability coefficient is as follows:

[0106] zs = C4 + C5

[0107] In the above implementation scheme of this application, by comprehensively considering multiple factors such as power difference, temperature difference, and electrical parameters, the stability degree of the circuit output power can be comprehensively and accurately evaluated, providing a more reliable basis for subsequent circuit optimization and maintenance.

[0108] In an optional embodiment of this application, according to the battery temperature change stability coefficient, the circuit environment resistance deviation coefficient, and the circuit output power stability coefficient, determining the precision coefficient includes:

[0109] Taking the square root of the sum of the battery temperature change stability coefficient and the circuit environment resistance deviation coefficient to obtain the first coefficient;

[0110] Squaring the circuit output power stability coefficient to obtain the second coefficient;

[0111] Calculating the ratio of the first coefficient and the second coefficient to obtain the precision coefficient.

[0112] In the embodiment of this application, the battery temperature change stability coefficient reflects the stability of the battery temperature in the state where the refrigerant channel is open; the circuit environment resistance deviation coefficient reflects the stability of the resistance parameters in the temperature detection circuit, and the deviation of the resistance may affect the accuracy of temperature detection, thereby affecting the judgment and control of the battery temperature; the circuit output power stability coefficient reflects the fluctuation of the output power in the temperature detection circuit, and unstable power will also interfere with the normal operation of temperature detection and the entire battery management system. By performing specific operations on these three coefficients to determine the precision coefficient, a comprehensive evaluation system can be constructed to comprehensively consider the working state of the battery system and its related circuits.

[0113] When calculating the precision coefficient, first take the square root of the sum of the battery temperature change stability coefficient and the circuit environment resistance deviation coefficient to obtain the first coefficient, which can balance their influence weights on the result to a certain extent, avoid being dominated by a certain coefficient due to its excessive value, and enable the precision coefficient to more comprehensively reflect the combined effect of the two. At the same time, square the circuit output power stability coefficient to obtain the second coefficient, which can amplify the influence degree of the circuit output power stability coefficient on the final result, because the stability of power is crucial for the stability of the temperature detection circuit and even the entire battery management system, and appropriately amplifying its influence helps to more prominently reflect the stability of the system. Finally, calculate the ratio of the first coefficient to the second coefficient to obtain the precision coefficient, so that the finally calculated precision coefficient comprehensively considers the mutual relationship of the three key factors of battery temperature, circuit resistance, and circuit power, can comprehensively reflect the precision and stability of the entire battery system and related circuits, and provides a simple and effective basis for adjusting the closing time of the refrigerant channel according to the precision coefficient later.

[0114] The calculation formula of the precision coefficient is as follows:

[0115]

[0116] Wherein, tp is the precision coefficient, is the first coefficient (wz is the battery temperature change stability coefficient, Qs d is the circuit environment resistance deviation coefficient), zs 2 is the second coefficient.

[0117] In the above implementation of the present application, by comprehensively considering multiple key factors such as battery temperature, circuit resistance, and circuit power, the precision coefficient can more comprehensively and accurately reflect the working state of the battery system and its related circuits, improve the accuracy of system state evaluation, provide a more reliable basis for subsequent control decisions, and thus avoid battery performance degradation or safety hazards caused by improper temperature control.

[0118] In an optional embodiment of the present application, adjusting the closing time of the refrigerant channel according to the precision coefficient includes:

[0119] Obtain a preset range and the predicted closing time of the refrigerant channel;

[0120] Compare the precision coefficient with the preset range;

[0121] When the precision coefficient is within the preset range, determine the predicted closing time as the closing time of the refrigerant channel;

[0122] When the precision coefficient is greater than the upper limit value of the preset range, determine the time point obtained by advancing the predicted closing time by a first preset duration as the closing time of the refrigerant channel;

[0123] When the precise coefficient is less than the lower limit value of the preset range, the time point obtained by delaying the predicted closing time by a second preset duration is determined as the closing time of the refrigerant channel.

[0124] Specifically, during the battery system development stage, the preset range of the precise coefficient can be determined based on a large amount of experimental data, theoretical analysis, and practical application experience. This preset range can be used as a threshold for judging the system stability. When the precise coefficient is within this preset range, it indicates that all parameters of the current battery system (such as the stability of temperature change, circuit resistance, circuit output power, and current deviation, etc., comprehensive factors) are within the acceptable normal fluctuation range. The refrigerant channel can operate according to the predicted closing time to maintain the stable operation of the system. For example, this preset range can be set as [0.03, 0.07]. It should be noted that as the battery is used and ages, its performance will change, and at the same time, different usage scenarios (such as extreme weather, frequent start-stop, etc.) will also have different impacts on the battery system. Therefore, the preset range can be dynamically adjusted according to factors such as the health status of the battery, the cumulative usage duration, and real-time environmental parameters. For example, when the battery has been used for a period of time, its internal resistance increases and its heat generation characteristics change, the preset range can be adjusted accordingly to adapt to the change in battery performance, so as to more accurately control the closing time of the refrigerant channel.

[0125] The predicted closing time can be the time point of the refrigerant channel closing predicted based on the normal working characteristics of the battery, heat dissipation requirements, and general operating scenarios when the system is initially set. This predicted closing time can be a reference time based on experience and preliminary calculation. For example, in the conventional driving mode, the refrigerant channel of the electric vehicle battery system is predicted to close 30 minutes after the battery starts working. This time is not fixed and will be determined according to the heat dissipation requirements of the battery.

[0126] By comparing the precise coefficient with the preset range, it is possible to quickly determine whether the operating state of the battery system deviates from the ideal situation. The comparison results include the following three cases:

[0127] When the precision coefficient is greater than the upper limit of the preset range, it indicates that the actual operating state of the battery system is relatively more stable than the preset ideal state. There may be excessive heat dissipation or other factors causing the system to be overly stable. At this time, in order to avoid the battery temperature being too low and affecting its performance, it is necessary to close the refrigerant channel in advance, that is, subtract the first preset duration from the expected closing time to obtain the closing time of the refrigerant channel. The first preset duration can be determined through experiments and experience. For example, the expected closing time is 30 minutes, and the precision coefficient is 0.08, which is greater than the upper limit of the preset range of 0.07. For this battery system, the first preset duration is set to 5 minutes, so the final closing time is 25 minutes. The battery management system will accordingly adjust the control logic to ensure that the refrigerant channel closes at the 25th minute.

[0128] When the precision coefficient is less than the lower limit of the preset range, it indicates that there are unstable factors in certain aspects of the battery system, such as unstable battery temperature changes and large circuit parameter deviations. In this case, in order to enhance heat dissipation or stabilize the system state, it is necessary to delay the closing of the refrigerant channel, that is, add the second preset duration to the expected closing time to obtain the closing time of the refrigerant channel. The second preset duration can also be determined through experiments and experience. For example, the expected closing time is 30 minutes, and the precision coefficient is 0.02, which is less than the lower limit of the preset range of 0.03. For this battery system, the second preset duration is 10 minutes, so the final closing time is 40 minutes. The battery management system will accordingly adjust the control logic to ensure that the refrigerant channel closes at the 40th minute.

[0129] When the precision coefficient is within the preset range, it indicates that the operating state of the battery system is normal, and the refrigerant channel can be closed according to the expected closing time to maintain the stable operation of the system. For example, the expected closing time is 30 minutes, and the precision coefficient is 0.05, which is within the preset range. At this time, the closing time of the refrigerant channel is determined as the expected closing time. The battery management system does not need to adjust the control logic, and the refrigerant channel closes at the 30th minute.

[0130] The opening and closing of the refrigerant channel directly affect the heat dissipation effect of the battery system, and thus affect the temperature of the battery. In the embodiments of the present application, the closing time of the refrigerant channel is adjusted according to the comparison result between the precision coefficient and the preset range, which can achieve precise control of the battery temperature. By reasonably controlling the closing timing of the refrigerant channel, it is possible to avoid the performance degradation, shortened lifespan, and even potential safety hazards of the battery caused by excessive temperature, and also prevent the battery activity and charge-discharge efficiency from being affected by too low temperature, thereby ensuring that the battery system always operates under the optimal temperature conditions and improving the service life and safety of the battery.

[0131] Optionally, a multi-stage control strategy can also be designed. For example, when the precision coefficient is slightly greater than the upper limit value, first reduce the refrigerant flow rate, and then decide whether to close it in advance according to the change of the precision coefficient after a period of time; when the precision coefficient is much smaller than the lower limit value, gradually extend the opening time of the refrigerant channel in stages, and at the same time monitor the recovery of various parameters of the battery system to avoid other problems caused by excessive adjustment.

[0132] In the above implementation scheme of the present application, by comparing the precision coefficient with the preset range to adjust the closing time of the refrigerant channel, the precise control of the battery temperature can be realized. In a high-temperature environment, by delaying the closing of the refrigerant channel, the battery temperature can be prevented from being too high and causing thermal runaway, ensuring the battery safety; in a low-temperature environment, by reasonably closing the refrigerant channel in advance, the energy waste caused by unnecessary refrigerant circulation can be avoided, and the battery can be prevented from being over-cooled, improving the charge and discharge efficiency of the battery, and thus effectively improving the performance and service life of the battery.

[0133] In an optional embodiment of the present application, the method further includes:

[0134] When the precision coefficient is not within the preset range, calculate the circuit environment current deviation coefficient;

[0135] Judge whether the precision coefficient is less than the circuit environment current deviation coefficient;

[0136] When the precision coefficient is less than the circuit environment current deviation coefficient, replace the precision coefficient with the circuit environment current deviation coefficient.

[0137] The embodiment of the present application also sets a preselection scheme. When the precision coefficient is not within the preset range, that is, less than the lower limit value of the preset range or greater than the upper limit value of the preset range, calculate the circuit environment current deviation coefficient, and judge whether the precision coefficient is less than the circuit environment current deviation coefficient.

[0138] Based on the fact that the precise coefficient reflects multiple key factors such as the battery temperature change stability coefficient, the circuit environment resistance deviation coefficient, and the circuit output power stability coefficient, when the precise coefficient is not within the preset range, it indicates that the operating state of the battery system and related circuits deviates from the ideal stable interval. At this time, relying solely on the precise coefficient may not accurately evaluate the system status, and more dimensions of analysis need to be introduced. The circuit environment current deviation coefficient reflects the degree of compliance between the stability of the current during the operation of the circuit and the expected value. When the precise coefficient is less than the circuit environment current deviation coefficient, it indicates that from the perspective of current deviation, the current precise coefficient fails to fully reflect the actual deviation of the circuit. At this time, the circuit environment current deviation coefficient can more accurately reflect the impact of the circuit state on the entire system. Therefore, when the precise coefficient is less than the circuit environment current deviation coefficient, the precise coefficient is replaced with the circuit environment current deviation coefficient, so that in subsequent system analysis and control decisions, operations can be based on parameters that are more in line with the actual situation, ensuring more accurate and effective management and control of the battery system.

[0139] In the above implementation of this application, when the precise coefficient is abnormal, by calculating the circuit environment current deviation coefficient and comparing and replacing it, the operating deviation of the battery system can be re-examined from different angles, improving the accuracy of evaluating the actual status of the system. Avoiding the limitations of a single precise coefficient in abnormal situations makes subsequent system operations based on this coefficient more in line with the real needs of the battery system, ensuring the stable operation of the system.

[0140] In an alternative embodiment of this application, calculating the circuit environment current deviation coefficient includes:

[0141] According to the current value, determine the initial current value and the stable current value, and calculate the interval duration between the initial time corresponding to the initial current value and the stable time corresponding to the stable current value to obtain the target interval duration;

[0142] Obtain the remaining energy of the battery when the temperature detection circuit is in a stable state;

[0143] Determine the ratio of the difference between the initial current value and the stable current value to the remaining energy as the third coefficient;

[0144] Determine the ratio of the sum of the initial current value and the stable current value to the target interval duration as the fourth coefficient;

[0145] Obtain the first weight corresponding to the third coefficient and the second weight corresponding to the fourth coefficient;

[0146] According to the third coefficient, the first weight, the fourth coefficient, and the second weight, obtain the circuit environment current deviation coefficient through a weighted algorithm.

[0147] When calculating the current deviation coefficient of the circuit environment, it is necessary to determine the initial current value and the stable current value from the continuously monitored current value data. Among them, the initial current value reflects the current situation at the moment when the circuit starts. As the circuit operates, the current gradually stabilizes, and the stable current value reflects the current level when the circuit reaches a stable state after running for a period of time. Calculate the time interval corresponding to the initial current value and the stable current value to obtain the target interval duration, which can be used to measure the time experienced by the circuit from startup to stable operation and is related to the dynamic characteristics of the circuit. At the same time, obtain the remaining energy of the battery when the temperature detection circuit is in a stable state. For example, the remaining energy of the battery is estimated in real time by the coulomb counting method, and when the temperature detection circuit is in a stable state, obtain the remaining energy of the battery at this time.

[0148] After obtaining the initial current value and the stable current value, determine the ratio of the difference between the initial current value and the stable current value to the remaining energy as the third coefficient. This third coefficient reflects the relationship between the current change amount and the remaining energy of the battery. The current change amount reflects the current fluctuation situation of the circuit from startup to stability, and being associated with the remaining energy can measure the impact degree of this current fluctuation on the battery from the energy perspective. For example, if the current change amount is large but the remaining energy of the battery is sufficient, this coefficient is relatively small, indicating that this current change is relatively reasonable within the battery energy bearing range; conversely, a larger coefficient may imply that the current change has a greater impact on battery energy consumption.

[0149] Determine the ratio of the sum of the initial current value and the stable current value to the target interval duration as the fourth coefficient. This fourth coefficient comprehensively considers the overall level of the current and the time required for the circuit to reach stability, and reflects the average change rate and overall level of the current within the target interval duration.

[0150] Obtain the first weight corresponding to the third coefficient and the second weight corresponding to the fourth coefficient. These first weight and second weight can be determined by regression analysis or empirical values. Finally, combine these two coefficients through a weighted algorithm to obtain the circuit environment current deviation coefficient. This coefficient comprehensively reflects various information such as the current change situation, the relationship with battery energy, and the efficiency of reaching the stable state during the process of the circuit starting to stabilize, can evaluate the matching degree between the current change and the energy state, and thus more accurately evaluate the deviation degree of the current in the circuit environment. The smaller the value of this coefficient, the more reasonable the current adjustment is.

[0151] The calculation formulas for the third coefficient and the fourth coefficient are as follows:

[0152] A3 = (I a - I b ) / O p

[0153] A4 = (I a + Ib ) / s

[0154] Wherein, A3 is the third coefficient, A4 is the fourth coefficient, I a is the initial current value, I b is the stable current value, s is the target interval duration, O p is the remaining energy of the battery.

[0155] The calculation formula for the current deviation coefficient of the circuit environment is as follows:

[0156] Tgl* = a1 * A3 + a2 * A4

[0157] Wherein, Tgl is the current deviation coefficient of the circuit environment, a1 is the first weight, and a2 is the second weight.

[0158] In the above embodiments of the present application, by comprehensively considering multiple factors such as the current change amount, the remaining energy of the battery, the overall current level, and the time for the circuit to reach stability, and adopting a weighted algorithm, it is possible to comprehensively and accurately evaluate the deviation degree of the current in the circuit environment.

[0159] The above introduced the battery temperature control method provided by the embodiments of the present application. Next, the battery temperature control device provided by the embodiments of the present application will be introduced in conjunction with the accompanying drawings.

[0160] As Figure 3 shown, the embodiments of the present invention also provide a battery temperature control device, and the device includes:

[0161] The first determination module 301 is configured to, when the refrigerant channel in the battery system is in an open state, detect the temperature of the battery and the working environment in the battery system to obtain the battery temperature and the working environment temperature, and determine the battery temperature change stability coefficient according to the battery temperature and the working environment temperature; wherein, the battery temperature is detected through a temperature detection circuit;

[0162] The second determination module 302 is configured to detect the resistance value and the current value of the first resistor in the temperature detection circuit, and determine the circuit environment resistance deviation coefficient and the circuit output power stability coefficient according to the resistance value and the current value; wherein, the temperature detection circuit includes a first operational amplifier, a second operational amplifier, and a first resistor, and the first resistor is connected between the output end of the first operational amplifier and the input end of the second operational amplifier;

[0163] The third determination module 303 is configured to determine the precise coefficient according to the battery temperature change stability coefficient, the circuit environment resistance deviation coefficient, and the circuit output power stability coefficient;

[0164] An adjustment module 304, configured to adjust the closing time of the refrigerant channel according to the precise coefficient to control the temperature of the battery in the battery system.

[0165] Optionally, the first determination module includes:

[0166] A first determination sub-module, configured to determine the initial battery temperature, the current battery temperature corresponding to the current acquisition time point, and the current working environment temperature according to the battery temperature and the working environment temperature; wherein, a preset time period is set between adjacent acquisition time points;

[0167] A current temperature difference calculation sub-module, configured to calculate the absolute value of the difference between the current battery temperature and the current working environment temperature to obtain the current temperature difference corresponding to the current acquisition time point;

[0168] An absolute value of temperature change calculation sub-module, configured to calculate the absolute value of the difference between the current temperature difference and the initial battery temperature to obtain the absolute value of temperature change;

[0169] A second determination sub-module, configured to determine a preset temperature change value according to the initial battery temperature, a preset temperature rise rate, and a target duration; wherein, the target duration is the time interval between the current acquisition time point and the initial acquisition time point;

[0170] A first parameter calculation sub-module, configured to calculate the absolute value of the difference between the absolute value of temperature change and the preset temperature change value to obtain a first parameter;

[0171] A second parameter calculation sub-module, configured to calculate the sum of the absolute value of temperature change and the preset temperature change value to obtain a second parameter;

[0172] A battery temperature change stability coefficient calculation sub-module, configured to calculate the product of the ratio of the first parameter to the second parameter and the preset time period to obtain the battery temperature change stability coefficient.

[0173] Optionally, the second determination module includes:

[0174] A ratio parameter determination sub-module, configured to, for each acquisition time point, determine the ratio of the resistance value corresponding to the acquisition time point to the acquisition time point as the ratio parameter corresponding to the acquisition time point;

[0175] An average value parameter determination sub-module, configured to, for each acquisition time point, determine the average value of the ratio parameter corresponding to the acquisition time point and the ratio parameter corresponding to the previous acquisition time point of the acquisition time point as the average value parameter corresponding to the acquisition time point;

[0176] A first acquisition sub-module, configured to acquire a circuit environment proportionality factor and a maximum deviation range of the ratio between the resistance value and the time point within a target time period at the current acquisition time point; wherein, the target time period is the time period between the current acquisition time point and the initial acquisition time point;

[0177] A resistance deviation value calculation sub-module, configured to calculate, for each acquisition time point, the product of the ratio of the maximum deviation range corresponding to the acquisition time point to the average value parameter and the circuit environment proportionality factor, to obtain the resistance deviation value corresponding to each acquisition time point;

[0178] A circuit environment resistance deviation coefficient calculation sub-module, configured to calculate the sum of the resistance deviation values corresponding to each acquisition time point within the target time period, to obtain the circuit environment resistance deviation coefficient.

[0179] Optionally, the second determination module includes:

[0180] A power difference calculation sub-module, configured to calculate, for each acquisition time point, the difference between the input power and the output power of the temperature detection circuit at the acquisition time point according to the resistance value and the current value, to obtain the power difference;

[0181] A fifth acquisition sub-module, configured to acquire, at the current acquisition time point, the temperature difference between the highest temperature and the lowest temperature detected by the temperature detection circuit, the output voltage value of the temperature detection circuit, and the conductivity coefficient of the first resistor;

[0182] A third parameter calculation sub-module, configured to calculate, at the current acquisition time point, the sum of the squares of the power differences within the target time period according to the power differences corresponding to each acquisition time point within the target time period, to obtain a third parameter, wherein the target time period is the time period between the current acquisition time point and the initial acquisition time point;

[0183] A fourth parameter calculation sub-module, configured to calculate, at the current acquisition time point, the square root of the ratio of the third parameter corresponding to the current acquisition point to the temperature difference corresponding to the current acquisition point, to obtain a fourth parameter;

[0184] A fifth parameter calculation sub-module, configured to calculate, at the current acquisition point, the product of the ratio of the output voltage value corresponding to the current acquisition point to the resistance value and the conductivity coefficient, to obtain a fifth parameter;

[0185] A circuit output power stability coefficient calculation sub-module, configured to determine the sum of the fourth parameter and the fifth parameter as the circuit output power stability coefficient.

[0186] Optionally, the third determination module includes:

[0187] The first processing sub-module is used to take the square root of the sum of the battery temperature change stability coefficient and the circuit environment resistance deviation coefficient to obtain a first coefficient;

[0188] The second processing sub-module is used to square the circuit output power stability coefficient to obtain a second coefficient;

[0189] The precise coefficient calculation sub-module is used to calculate the ratio of the first coefficient and the second coefficient to obtain the precise coefficient.

[0190] Optionally, the adjustment module includes:

[0191] The fourth acquisition sub-module is used to acquire a preset range and the estimated closing time of the refrigerant channel;

[0192] The comparison sub-module is used to compare the precise coefficient with the preset range;

[0193] The first closing time determination sub-module is used to determine the closing time of the refrigerant channel as the estimated closing time when the precise coefficient is within the preset range;

[0194] The second closing time determination sub-module is used to determine the closing time of the refrigerant channel as the time point obtained by advancing the estimated closing time by a first preset duration when the precise coefficient is greater than the upper limit value of the preset range;

[0195] The third closing time determination sub-module is used to determine the closing time of the refrigerant channel as the time point obtained by delaying the estimated closing time by a second preset duration when the precise coefficient is less than the lower limit value of the preset range.

[0196] Optionally, the device further includes:

[0197] The calculation module is used to calculate the circuit environment current deviation coefficient when the precise coefficient is not within the preset range;

[0198] The judgment module is used to judge whether the precise coefficient is less than the circuit environment current deviation coefficient;

[0199] The replacement module is used to replace the precise coefficient with the circuit environment current deviation coefficient when the precise coefficient is less than the circuit environment current deviation coefficient.

[0200] Optionally, the calculation module includes:

[0201] The first calculation sub-module is used to determine an initial current value and a stable current value according to the current value, and calculate the interval duration between the initial moment corresponding to the initial current value and the stable moment corresponding to the stable current value to obtain a target interval duration;

[0202] A second acquisition sub-module, configured to acquire the remaining energy of the battery when the temperature detection circuit is in a stable state;

[0203] A third determination sub-module, configured to determine, as a third coefficient, a ratio of a difference between the initial current value and the stable current value to the remaining energy;

[0204] A fourth determination sub-module, configured to determine, as a fourth coefficient, a ratio of a sum of the initial current value and the stable current value to the target interval duration;

[0205] A third acquisition sub-module, configured to acquire a first weight corresponding to the third coefficient and a second weight corresponding to the fourth coefficient;

[0206] A circuit environment current deviation coefficient calculation sub-module, configured to obtain the circuit environment current deviation coefficient through a weighting algorithm according to the third coefficient, the first weight, the fourth coefficient, and the second weight.

[0207] The battery temperature control device provided in this application. In the embodiments of this application, when the refrigerant channel in the battery system is in an open state, various working data of the battery system are collected, and according to the battery temperature and the working environment temperature in the working data, a battery temperature change stability coefficient indicating whether the battery temperature fluctuation is within a safe range is determined. At the same time, according to the resistance value and the current value of the first resistor in the working data, a circuit environment resistance deviation coefficient indicating whether the resistance change exceeds the expected range and a circuit output power stability coefficient indicating the power transmission efficiency and stability are determined. Then, an accurate coefficient is determined according to the above coefficients, and the accurate coefficient can comprehensively consider multiple factors such as battery temperature change, circuit environment resistance deviation, and circuit output power stability. And according to the accurate coefficient, the closing time of the refrigerant channel is adjusted to control the battery temperature in the battery system. This application can avoid the problem that when the battery management system issues an instruction to exit cooling, the residual refrigerant in the refrigerant channel continues to cool the battery, causing the battery temperature to continue to drop, affecting the service life and safety performance of the battery, thereby improving the cycle times and performance retention rate of the battery, and providing guarantee for the long-term stable use of the battery.

[0208] For the device embodiments, since they are basically similar to the method embodiments, the description is relatively simple. For related parts, refer to the partial description of the method embodiments.

[0209] The embodiments of this application also provide an electronic device, including: a processor, a memory, and a computer program stored on the memory and executable on the processor. When the computer program is executed by the processor, it implements each process of the above battery temperature control method embodiments and can achieve the same technical effects. To avoid repetition, it will not be elaborated here.

[0210] For example, Figure 4 shows a schematic diagram of the physical structure of an electronic device. As Figure 4 shown, the electronic device may include: a processor 410, a communication interface 420, a memory 430, and a communication bus 440. Among them, the processor 410, the communication interface 420, and the memory 430 complete mutual communication through the communication bus 440. The processor 410 can call the logical instructions in the memory 430. The processor 410 is configured to perform the following steps: When the refrigerant channel in the battery system is in an open state, perform temperature detection on the battery in the battery system and the working environment where the battery is located to obtain the battery temperature and the working environment temperature, and determine the battery temperature change stability coefficient according to the battery temperature and the working environment temperature; wherein, the battery temperature is detected by a temperature detection circuit; detect the resistance value and the current value of the first resistor in the temperature detection circuit to obtain the resistance value and the current value, and determine the circuit environment resistance deviation coefficient and the circuit output power stability coefficient according to the resistance value and the current value; wherein, the temperature detection circuit includes a first operational amplifier, a second operational amplifier, and a first resistor, and the first resistor is connected between the output terminal of the first operational amplifier and the input terminal of the second operational amplifier; determine the accuracy coefficient according to the battery temperature change stability coefficient, the circuit environment resistance deviation coefficient, and the circuit output power stability coefficient; adjust the closing time of the refrigerant channel according to the accuracy coefficient to control the temperature of the battery in the battery system. The processor 410 can also execute other solutions in the embodiments of the present application, which will not be further elaborated here.

[0211] In addition, when the logical instructions in the above-mentioned memory 430 are implemented in the form of a software functional unit and sold or used as an independent product, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application.

[0212] The embodiments of the present application also provide a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements each process of the above-mentioned embodiment of the battery temperature control method and can achieve the same technical effect. To avoid repetition, it will not be elaborated here. Among them, the computer-readable storage medium is, for example, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disc, etc.

[0213] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of another identical element in the process, method, article or device including the element.

[0214] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disc) and includes several instructions for causing a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in the various embodiments of the present application.

[0215] The above describes the embodiments of the present application in conjunction with the drawings, but the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all belong to the protection scope of the present application.

[0216] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in the embodiments of the present application can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0217] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0218] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of the devices or units can be in electrical, mechanical, or other forms.

[0219] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0220] In addition, in each embodiment of the present application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0221] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or a part of this technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, ROM, RAM, magnetic disks, or optical discs that can store program codes.

[0222] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application and should be covered by the protection scope of the present application.

Claims

1. A battery temperature control method, characterized in that, The method includes: When the refrigerant channel in the battery system is in an open state, detecting the temperature of the battery in the battery system and the working environment where the battery is located to obtain the battery temperature and the working environment temperature, and determining a battery temperature change stability coefficient according to the battery temperature and the working environment temperature; wherein, the battery temperature is detected by a temperature detection circuit; Detecting the resistance value and current value of the first resistor in the temperature detection circuit to obtain the resistance value and the current value, and determining a circuit environment resistance deviation coefficient and a circuit output power stability coefficient according to the resistance value and the current value; wherein, the temperature detection circuit includes a first operational amplifier, a second operational amplifier and a first resistor, and the first resistor is connected between the output end of the first operational amplifier and the input end of the second operational amplifier; Determining an accuracy coefficient according to the battery temperature change stability coefficient, the circuit environment resistance deviation coefficient and the circuit output power stability coefficient; Adjusting the closing time of the refrigerant channel according to the accuracy coefficient to control the temperature of the battery in the battery system.

2. The battery temperature control method according to claim 1, wherein Determining the battery temperature change stability coefficient according to the battery temperature and the working environment temperature includes: Determining the initial battery temperature, the current battery temperature corresponding to the current acquisition time point and the current working environment temperature corresponding to the current acquisition time point according to the battery temperature and the working environment temperature; wherein, a preset time duration is set between adjacent acquisition time points; Calculating the absolute value of the difference between the current battery temperature and the current working environment temperature to obtain the current temperature difference corresponding to the current acquisition time point; Calculating the absolute value of the difference between the current temperature difference and the initial battery temperature to obtain the absolute value of the temperature change; Determining a preset temperature change value according to the initial battery temperature, a preset temperature rise rate and a target time duration; wherein, the target time duration is the time interval between the current acquisition time point and the initial acquisition time point; Calculating the absolute value of the difference between the absolute value of the temperature change and the preset temperature change value to obtain a first parameter; Calculating the sum of the absolute value of the temperature change and the preset temperature change value to obtain a second parameter; Calculating the product of the ratio of the first parameter to the second parameter and the preset time duration to obtain the battery temperature change stability coefficient.

3. The battery temperature control method according to claim 1, wherein Determining the circuit environment resistance deviation coefficient includes: For each acquisition time point, determining the ratio of the resistance value corresponding to the acquisition time point to the acquisition time point as the ratio parameter corresponding to the acquisition time point; For each acquisition time point, determining the average value of the ratio parameter corresponding to the acquisition time point and the ratio parameter corresponding to the previous acquisition time point of the acquisition time point as the average value parameter corresponding to the acquisition time point; At the current acquisition time point, obtaining a circuit environment proportionality factor and the maximum deviation range of the ratio between the resistance value and the time point within a target time period; wherein, the target time period is the time period between the current acquisition time point and the initial acquisition time point; For each acquisition time point, calculate the product of the ratio of the maximum deviation range corresponding to the acquisition time point to the average value parameter and the circuit environment proportionality factor to obtain the resistance deviation value corresponding to each acquisition time point; Calculate the sum of the resistance deviation values corresponding to each acquisition time point within the target time period to obtain the circuit environment resistance deviation coefficient.

4. The battery temperature control method according to claim 1, wherein, Determine the circuit output power stability coefficient according to the resistance value and the current value, including: For each acquisition time point, calculate the difference between the input power and the output power of the temperature detection circuit at the acquisition time point according to the resistance value and the current value to obtain the power difference; At the current acquisition time point, obtain the temperature difference between the highest temperature and the lowest temperature detected by the temperature detection circuit, the output voltage value of the temperature detection circuit, and the conductivity coefficient of the first resistor; At the current acquisition time point, calculate the sum of the squares of the power differences within the target time period according to the power differences corresponding to each acquisition time point within the target time period, where the target time period is the time period between the current acquisition time point and the initial acquisition time point, to obtain a third parameter; At the current acquisition time point, take the square root of the ratio of the third parameter corresponding to the current acquisition point to the temperature difference corresponding to the current acquisition point to obtain a fourth parameter; At the current acquisition point, calculate the product of the ratio of the output voltage value corresponding to the current acquisition point to the resistance value and the conductivity coefficient to obtain a fifth parameter; Determine the sum of the fourth parameter and the fifth parameter as the circuit output power stability coefficient.

5. The battery temperature control method according to claim 1, wherein Determine the precision coefficient according to the battery temperature change stability coefficient, the circuit environment resistance deviation coefficient, and the circuit output power stability coefficient, including: Take the square root of the sum of the battery temperature change stability coefficient and the circuit environment resistance deviation coefficient to obtain a first coefficient; Square the circuit output power stability coefficient to obtain a second coefficient; Calculate the ratio of the first coefficient and the second coefficient to obtain the precision coefficient.

6. The battery temperature control method according to any one of claims 1 to 5, characterized in that, Adjust the closing time of the refrigerant channel according to the precision coefficient, including: Obtain the preset range and the estimated closing time of the refrigerant channel; Compare the precision coefficient with the preset range; When the precision coefficient is within the preset range, determine the estimated closing time as the closing time of the refrigerant channel; When the precision coefficient is greater than the upper limit value of the preset range, determine the time point obtained by advancing the estimated closing time by a first preset duration as the closing time of the refrigerant channel; When the precision coefficient is less than the lower limit value of the preset range, determine the time point obtained by delaying the estimated closing time by a second preset duration as the closing time of the refrigerant channel.

7. The battery temperature control method according to claim 6, wherein The method further includes: When the precision coefficient is not within the preset range, calculate the circuit environment current deviation coefficient; Judge whether the precision coefficient is less than the circuit environment current deviation coefficient; When the precision coefficient is less than the circuit environment current deviation coefficient, replace the precision coefficient with the circuit environment current deviation coefficient.

8. The battery temperature control method according to claim 7, wherein Calculate the circuit environment current deviation coefficient, including: Determine an initial current value and a stable current value according to the current value, and calculate an interval duration between an initial moment corresponding to the initial current value and a stable moment corresponding to the stable current value to obtain a target interval duration; Obtain the remaining energy of the battery when the temperature detection circuit is in a stable state; Determine a third coefficient as a ratio of a difference between the initial current value and the stable current value to the remaining energy; Determine a fourth coefficient as a ratio of a sum of the initial current value and the stable current value to the target interval duration; Obtain a first weight corresponding to the third coefficient and a second weight corresponding to the fourth coefficient; Obtain the circuit environment current deviation coefficient through a weighted algorithm according to the third coefficient, the first weight, the fourth coefficient, and the second weight.

9. A battery temperature control device, characterized in that, Comprising: A first determination module, configured to, when a refrigerant channel in a battery system is in an open state, detect temperatures of a battery and a working environment where the battery is located in the battery system to obtain a battery temperature and a working environment temperature, and determine a battery temperature change stability coefficient according to the battery temperature and the working environment temperature; wherein the battery temperature is detected through a temperature detection circuit; A second determination module, configured to detect a resistance value and a current value of a first resistor in the temperature detection circuit to obtain the resistance value and the current value, and determine a circuit environment resistance deviation coefficient and a circuit output power stability coefficient according to the resistance value and the current value; wherein the temperature detection circuit includes a first operational amplifier, a second operational amplifier, and a first resistor, and the first resistor is connected between an output end of the first operational amplifier and an input end of the second operational amplifier; A third determination module, configured to determine an accuracy coefficient according to the battery temperature change stability coefficient, the circuit environment resistance deviation coefficient, and the circuit output power stability coefficient; An adjustment module, configured to adjust a closing time of the refrigerant channel according to the accuracy coefficient to control the temperature of the battery in the battery system.

10. An electronic device, characterized in that, Comprising a processor, a memory, and a computer program stored on the memory and executable on the processor, where the computer program, when executed by the processor, implements the battery temperature control method according to any one of claims 1 to 8.

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