Cooling control method and cooling assembly of electric automobile and automobile

Abstract

The invention discloses a cooling control method of an electric automobile, a cooling assembly and the automobile. The method comprises the steps that whether a power battery meets a cooling starting condition or not is judged according to the environment temperature and battery state information; if the power battery meets the cooling starting condition, controlling a cooling assembly to operate to enable the power battery to enter a cooling mode; dynamically adjusting the cooling strategy of the cooling assembly according to the change of the battery state information in the cooling mode; and if the power battery meets the cooling stop condition, controlling the cooling assembly to operate to enable the power battery to exit the cooling mode. Whether cooling needs to be started or not is comprehensively judged through the environment temperature and the battery state information, and the cooling strategy is dynamically adjusted through the battery state change after cooling is started, so that early starting and accurate regulation and control of power battery cooling are achieved, rapid temperature rise of the power battery is avoided, the charging efficiency is improved, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of battery cooling and temperature control, and in particular to a cooling control method, a cooling component and an electric vehicle. Background Art

[0002] With the rapid development of electric vehicle technology, the performance and safety of power batteries, as the core components of electric vehicles, are receiving more and more attention. The existing electric vehicle power battery cooling temperature control method usually uses a fixed temperature threshold to trigger cooling, and at the same time controls the power battery cooling inlet water temperature to a constant value. When the power battery is charged slowly and the heat generation is small, the power battery cooling temperature control needs can be met.

[0003] However, as the charging speed of power batteries is getting faster and faster and the charging heat is getting higher and higher, the existing cooling control methods can no longer fully meet the cooling and temperature control requirements of power batteries. When the power battery is charged at a high rate with a higher current, the cooling is turned on after the power battery reaches a fixed temperature threshold. The triggering of the cooling is greatly delayed, causing the power battery temperature to rise sharply, reaching the upper limit of the permissible temperature for high-rate charging more quickly, and the duration of high-rate charging is reduced, resulting in a limited increase in charging speed. In addition, when the cooling is turned on, the power battery is cooled with a constant cooling inlet water temperature, which cannot suppress the temperature rise rate of the power battery in the early stage of charging, thereby affecting the charging speed. It is also not conducive to reducing the battery temperature difference and system energy consumption in the later stage of charging, affecting the battery life and system energy consumption.

[0004] In view of this, it is necessary to provide a cooling control method that can meet the cooling requirements of power batteries under high-rate charging conditions. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a cooling control method for an automobile battery, which comprehensively judges whether cooling needs to be turned on through ambient temperature and battery status information, and dynamically adjusts the cooling strategy through changes in battery status after cooling is turned on, so as to realize early start and precise control of power battery cooling, avoid a sharp rise in power battery temperature, speed up the charging efficiency of the power battery and extend the service life of the power battery, so that the temperature control capability of the power battery can meet the needs of high-rate charging.

[0006] The technical solution of the present invention provides a cooling control method for a vehicle battery, comprising:

[0007] Determine whether the power battery meets the cooling start condition according to the ambient temperature and battery status information;

[0008] If the power battery meets the cooling start-up condition, controlling the cooling component to operate so that the power battery enters a cooling mode;

[0009] Dynamically adjusting the cooling strategy of the cooling component according to the change of the battery status information in the cooling mode;

[0010] If the power battery meets the cooling stop condition, the cooling component is controlled to operate to make the power battery exit the cooling mode.

[0011] In one of the optional technical solutions, judging whether the power battery meets the cooling start condition according to the ambient temperature and the battery status information includes:

[0012] If the power battery is in a charging state, the power battery is tested;

[0013] The charging current value, the maximum battery cell temperature value, the minimum battery cell temperature value and the cooling inlet water temperature value of the power battery are measured respectively and combined to generate battery status information;

[0014] If the maximum battery cell temperature value is greater than or equal to the first temperature threshold, it is determined that the power battery meets the cooling start condition;

[0015] If the charging current value is continuously greater than or equal to the charging current threshold value within a preset time, and the lowest battery cell temperature value is greater than or equal to the second temperature threshold value, it is determined that the power battery meets the cooling start-up condition.

[0016] In one of the optional technical solutions, the charging current threshold is calculated by using the difference between the maximum battery cell temperature value and a reference temperature value, the difference between the ambient temperature and the reference temperature value, and characteristic parameters of the power battery.

[0017] In one of the optional technical solutions, judging whether the power battery meets the cooling start condition according to the ambient temperature and the battery status information further includes:

[0018] The temperature value of each battery cell is collected at intervals within a preset time, and the temperature rise rate of each battery cell is calculated respectively;

[0019] Calculating a temperature change trend of the power battery based on the charging current value and the temperature rise rate;

[0020] If the temperature change trend meets the rapid temperature rise condition, it is determined that the power battery meets the cooling start condition.

[0021] In one of the optional technical solutions, the controlling the cooling assembly to operate so that the power battery enters a cooling mode includes:

[0022] Calculate a target water temperature value according to the charging current value, the maximum battery core temperature value, the minimum battery core temperature value and the ambient temperature;

[0023] Calculating the temperature difference between the cooling inlet water temperature value and the target water temperature value;

[0024] The cooling power of the cooling assembly is determined based on the temperature difference value, so that the power battery enters a cooling mode until the cooling inlet water temperature value is equal to the target water temperature value.

[0025] In one of the optional technical solutions, dynamically adjusting the cooling strategy of the cooling component according to the change of the battery status information in the cooling mode includes:

[0026] Calculating a maximum cell temperature difference value by using the maximum cell temperature value and the minimum cell temperature value, and judging whether the power battery meets a cell temperature difference excessive condition according to the maximum cell temperature difference value;

[0027] If the maximum temperature difference of the battery cell does not meet the condition that the temperature difference of the battery cell is too large, the target water temperature value is not changed;

[0028] If the maximum temperature difference value of the battery cells meets the condition that the temperature difference of the battery cells is too large, the target water temperature value is adjusted based on the maximum temperature difference value of the battery cells.

[0029] In one of the optional technical solutions, judging whether the power battery meets the condition of excessive temperature difference of the battery cell according to the maximum temperature difference value of the battery cell includes:

[0030] If the maximum temperature difference value of the battery cell is less than or equal to the first temperature difference threshold, it is determined that the power battery does not meet the condition of excessive temperature difference of the battery cell, and the target water temperature value is not changed;

[0031] If the maximum temperature difference of the battery cell is greater than the first temperature difference threshold and less than or equal to the second temperature difference threshold, it is determined that the power battery meets the condition of excessive temperature difference of the battery cell, and a temperature compensation value is calculated according to the maximum temperature difference of the battery cell to be added to the target water temperature value;

[0032] If the maximum temperature difference of the battery cell is greater than the second temperature difference threshold, it is determined that the power battery meets the condition of excessive temperature difference of the battery cell, and the target water temperature value is adjusted to the maximum cooling water temperature value allowed by the cooling component.

[0033] In one of the optional technical solutions, if the power battery meets the cooling stop condition, controlling the cooling component to operate so that the power battery exits the cooling mode includes:

[0034] If the charging current value is continuously less than the charging current threshold value within a preset time, and the highest battery cell temperature value is less than or equal to a third temperature threshold value, it is determined that the power battery meets the cooling stop condition.

[0035] The technical solution of the present invention provides a cooling component for implementing any of the aforementioned cooling control methods for automobile batteries, including a refrigeration circuit and a heat exchange circuit connected to a power battery, wherein the refrigeration circuit and the heat exchange circuit are connected via a battery cooler, the refrigeration circuit includes a compressor, a condenser, a condenser fan, a battery cooler, an electronic expansion valve and a temperature and pressure sensor, and the heat exchange circuit includes an electronic water pump and a water temperature sensor.

[0036] The technical solution of the present invention provides a car, including a car body, in which the aforementioned cooling component is arranged, and the cooling component can implement any step of the aforementioned car battery cooling control method.

[0037] The above technical solution has the following beneficial effects:

[0038] The cooling control method of the electric vehicle provided by the present invention comprehensively judges whether cooling needs to be turned on through the ambient temperature and battery status information, and dynamically adjusts the cooling strategy through the change of the battery status after the cooling is turned on, so as to realize the early start of cooling of the power battery before the temperature is too high and realize precise control during the cooling process. When the power battery is in a high-rate charging state, the possible rapid temperature rise is predicted through multi-dimensional information to turn on the cooling temperature control in advance. In the cooling mode, the cooling strategy of the cooling component is dynamically adjusted according to the change of the battery status information to improve the cooling power and cooling accuracy. By cooling the power battery through the method of the present invention, energy waste caused by excessive cooling can be avoided through precise temperature control and dynamic adjustment of the cooling strategy, so as to improve the overall energy utilization efficiency of the electric vehicle, and can also effectively reduce the risk of thermal runaway of the power battery in a high temperature environment, extend the service life of the power battery, and improve the safety and reliability of the electric vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The disclosure of the present invention will become more easily understood with reference to the accompanying drawings. It should be understood that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present invention. In the drawings:

[0040] Figure 1 A flowchart of a cooling control method for a vehicle battery provided by an embodiment of the present invention;

[0041] Figure 2 A flowchart of a cooling control method for a vehicle battery provided by another embodiment of the present invention;

[0042] Figure 3 A flowchart of a cooling control method for a vehicle battery provided by another embodiment of the present invention;

[0043] Figure 4A flowchart of a cooling control method for a vehicle battery provided by another embodiment of the present invention;

[0044] Figure 5 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0046] It should be noted that the automotive battery mentioned below refers to the storage battery that provides power for electric vehicles, hybrid vehicles and other vehicles. The power battery is also responsible for supplying power to the high-voltage power system of electric vehicles. The power battery can store electrical energy and release it when needed, and supports repeated charging and use. In order to meet the needs of long-distance driving of vehicles, the power battery needs to have a higher energy density, that is, it can store more electrical energy per unit volume or weight. Among them, lithium-ion power batteries are generally used in electric vehicles. The migration of lithium ions between the positive and negative electrodes is used to store and release electrical energy. It has the advantages of high energy density, long cycle life, and low self-discharge rate.

[0047] Power batteries generally include multiple cells, which are combined in series or in parallel to form a battery module. Multiple battery modules are further combined into a battery pack, which ultimately constitutes the entire power battery system. The cell is the smallest unit of a power battery and is responsible for storing and releasing electrical energy. Each cell has certain performance indicators such as voltage, capacity, and energy density. In a power battery, the performance of the cell directly affects the performance of the entire battery pack, and during the charging and discharging process, the temperature and state of each cell are different.

[0048] High-rate charging of power batteries refers to the process of charging power batteries at a high current rate in a short period of time. This charging method is of great significance for improving charging efficiency and shortening charging time, and is particularly suitable for application scenarios that require fast charging, such as electric vehicles. High-rate charging can charge a large amount of electrical energy into the power battery in a short period of time, significantly shortening the charging time. This is crucial to improving user experience and increasing device efficiency. Batteries charged at high rates usually have high power output capabilities and can meet the operating requirements of devices under high power demands. High-rate charging places higher requirements on battery thermal management, safety, and other aspects. Batteries may generate a lot of heat during fast charging, and effective heat dissipation measures are required to prevent overheating. At the same time, high-rate charging may also aggravate side reactions inside the battery, affecting the cycle life and safety of the battery. High-rate charging of power batteries is an efficient and fast charging method, which is of great significance for improving device efficiency and meeting high power demands. However, achieving high-rate charging requires overcoming a series of technical challenges. To this end, it is necessary to optimize the cooling control method of power batteries under high-rate charging.

[0049] like Figure 1 A cooling control method for a vehicle battery provided by an embodiment of the present invention is shown, comprising:

[0050] Step S101: judging whether the power battery meets the cooling start condition according to the ambient temperature and the battery status information.

[0051] Step S102: If the power battery meets the cooling start-up condition, control the cooling component to operate so that the power battery enters a cooling mode.

[0052] Step S103: dynamically adjusting the cooling strategy of the cooling component according to the change of the battery status information in the cooling mode.

[0053] Step S104: If the power battery meets the cooling stop condition, control the cooling assembly to operate so that the power battery exits the cooling mode.

[0054] Specifically, unlike the traditional cooling start-up condition that only takes whether the current temperature of the power battery is greater than a preset value, step S101 of this embodiment also refers to the ambient temperature and the battery status information of the power battery. The battery status information may include multiple operating parameters of the power battery obtained by real-time detection, such as charging voltage, charging current, charging time, battery cell temperature, etc. By comprehensively considering the ambient temperature and battery status information, the cooling demand of the power battery can be accurately judged. Compared with the traditional single temperature threshold control cooling start-up method, the comprehensive evaluation method provided by this embodiment is more adaptable to the high-rate charging state with complex and changeable operating conditions, so as to ensure battery safety while optimizing energy utilization efficiency, and can also predict in advance whether the power battery will overheat if it continues to charge in the current state.

[0055] Step S102 controls the operation of the cooling component to put the power battery into cooling mode. As an example, the cooling component includes a refrigeration circuit and a heat exchange circuit connected to the power battery. The refrigeration circuit and the heat exchange circuit are connected through a battery cooler. The main function of the refrigeration circuit is to evaporate the internal refrigerant in the battery cooler to absorb heat to achieve refrigeration. It generally includes a compressor, a condenser, a condenser fan, a battery cooler, an electronic expansion valve, and a temperature and pressure sensor, and absorbs the heat of the coolant in the heat exchange circuit through the battery cooler. The heat exchange circuit includes an electronic water pump and a water temperature sensor. The water temperature sensor is arranged at the coolant inlet of the power battery to measure the water temperature value of the cooling inlet of the power battery. The cooling inlet mentioned below refers to the port on the power battery for the coolant to enter. In actual use, the coolant in the heat exchange circuit can be a 50% volume ratio of ethylene glycol aqueous solution. Therefore, the water temperature mentioned below refers to the temperature of the coolant in the heat exchange circuit.

[0056] Step S103 takes into account the significant differences in cooling requirements of power batteries under different environmental conditions, such as high temperature, low temperature or large cell temperature difference, and power batteries under different charging states, such as fast charging, slow charging or static state. Therefore, this embodiment detects the dynamic changes of ambient temperature and battery status information in real time, accurately determines when to start the cooling system, cooling time and cooling temperature, that is, controls the cooling strategy of the cooling component to avoid the cooling intervention of the cooling component on the power battery too early or too late, thereby reducing energy waste and effectively extending the battery life. By dynamically adjusting the cooling strategy, it can ensure that the power battery can adopt a reasonable cooling strategy in various charging and discharging scenarios, especially pre-executing efficient cooling behavior in the high-rate charging state, which can avoid the situation where the power battery temperature is too high and cannot continue high-rate charging, and significantly improve the continuity and safety of high-rate charging of the power battery.

[0057] Step S104 is to determine whether the power battery meets the cooling stop condition. When the power battery has met the corresponding condition and ensures that the power battery can be continuously charged at a high rate for a period of time, the main control module can be used to control the cooling component to operate so that the power battery exits the cooling mode to avoid battery overcooling and energy waste. While improving the continuity and safety of high-rate charging of the power battery, energy can also be saved to avoid a significant decrease in the endurance of the vehicle due to the cooling control method of the electric vehicle provided by the present invention.

[0058] Through the above steps, the cooling time of the power battery can be accurately predicted, the response speed and accuracy of the cooling component can be improved, and the performance degradation and safety hazards of the power battery caused by overheating can be effectively reduced, while the energy utilization efficiency of the whole vehicle can also be optimized.

[0059] In summary, the cooling control method of the electric vehicle provided in this embodiment comprehensively judges whether cooling needs to be turned on through the ambient temperature and battery status information, and dynamically adjusts the cooling strategy through the change of battery status after cooling is turned on, so as to realize the early start of cooling of the power battery before the temperature is too high and realize precise regulation during the cooling process. When the power battery is in a high-rate charging state, the possible rapid temperature rise is predicted through multi-dimensional information to turn on the cooling temperature control in advance. In the cooling mode, the cooling strategy of the cooling component is dynamically adjusted according to the change of battery status information, which can improve the cooling power and cooling accuracy.

[0060] In addition, by controlling the cooling of the power battery through the method of the present invention, unnecessary energy waste can be avoided through precise temperature control and dynamic adjustment of the cooling strategy, so as to improve the overall energy utilization efficiency of the electric vehicle. It can also effectively reduce the risk of thermal runaway of the power battery in a high temperature environment, minimize the overheating time of the power battery in a high-rate charging state, extend the service life of the power battery, and improve the safety and reliability of the electric vehicle.

[0061] In one embodiment, Figure 2 As shown, step S101 includes:

[0062] Step S201: If the power battery is in a charging state, the power battery is tested.

[0063] Step S202: respectively measuring the charging current value, the maximum battery cell temperature value, the minimum battery cell temperature value and the cooling inlet water temperature value of the power battery and combining them to generate battery status information.

[0064] Step S203: If the maximum battery cell temperature value is greater than or equal to the first temperature threshold, it is determined that the power battery meets the cooling start condition.

[0065] Step S204: If the charging current value is continuously greater than or equal to the charging current threshold value within a preset time, and the lowest battery cell temperature value is greater than or equal to the second temperature threshold value, it is determined that the power battery meets the cooling start-up condition.

[0066] In this embodiment, the temperature of each cell in the power battery needs to be measured respectively, and the cell temperature with the highest temperature and the cell temperature with the lowest temperature are selected as the highest cell temperature and the lowest cell temperature respectively. In step S203, by judging whether the highest cell temperature is greater than or equal to the first temperature threshold, it can be determined whether the power battery has been partially overheated or has a tendency to overheat, and then it can be judged that the power battery meets the cooling start condition, and the current power battery needs to be cooled.

[0067] In step S204, if the highest cell temperature is less than the first temperature threshold, but the charging current value is continuously greater than or equal to the charging current threshold, in order to avoid misjudgment caused by an instantaneous increase in the charging current, the preferred duration is 10 seconds. If this condition is met, it can be determined that the power battery is in a high-rate charging state. At this time, it is necessary to further determine whether the power battery has an overheating trend, and ensure that the lowest cell temperature is greater than or equal to the second temperature threshold to prevent the temperature of some cells of the power battery from being too low after cooling is turned on. If both the charging current value and the lowest cell temperature meet the conditions, it can be determined that the power battery meets the cooling turn-on conditions, and the current power battery needs to be cooled.

[0068] Furthermore, the charging current threshold is calculated as:

[0069] I v =I p -α 1 (T max -T)-β 1 (T amb -T)

[0070] Among them, I v is the charging current threshold, I p is the reference current value, α 1 is the first temperature coefficient, β 1 is the second temperature coefficient, T max is the maximum cell temperature, T amb is the ambient temperature, and T is the reference temperature. p , α 1 , β 1 and T are fixed values ​​obtained based on the characteristics and calibration of the power battery and cooling components. The designer can also change I p , α 1 , β 1 and T values, as an example, I pFor 250A, α 1 is 6, β 1 is 3, T is 25.

[0071] This embodiment improves the flexibility and accuracy of setting the charging current threshold, thereby avoiding safety hazards caused by low charging efficiency due to a single fixed threshold or incorrectly triggering cooling in extreme environments, thereby further ensuring the safety and stability of the power battery.

[0072] In one embodiment, the charging current threshold is calculated by the difference between the maximum battery cell temperature value and the reference temperature value, the difference between the ambient temperature and the reference temperature value, and the characteristic parameters of the power battery.

[0073] In this embodiment, the charging current threshold is obtained by dynamic calculation, and the calculation process can take into account the difference between the maximum cell temperature and the reference temperature, the difference between the ambient temperature and the reference temperature, and the inherent characteristic parameters of the power battery, such as heat capacity, thermal resistance, etc. The dynamic adjustment mechanism based on real-time data and battery characteristics makes the setting of the charging current threshold more scientific and reasonable.

[0074] The thermal response characteristics of the battery will be different under different temperature environments. By introducing the relative difference between the reference temperature and the cell temperature and environment, and combining the physical properties of the battery itself, the heat accumulation rate of the battery during the charging process can be more accurately evaluated, thereby formulating a more appropriate current limit standard to ensure that the battery operates within a safe range.

[0075] In one embodiment, Figure 2 As shown, step S101 also includes:

[0076] Step S205: collecting the temperature value of each battery cell at intervals within a preset time, and calculating the temperature rise rate of each battery cell respectively.

[0077] Step S206: Calculating the temperature change trend of the power battery based on the charging current value and the temperature rise rate.

[0078] Step S207: If the temperature change trend meets the rapid temperature rise condition, it is determined that the power battery meets the cooling start condition.

[0079] In this embodiment, the temperature value of the battery cell is collected at intervals within a preset time, and the heating rate is calculated. Combined with the charging current value, the thermal model is used to predict the future temperature change trend of the power battery. This prediction method combines the advantages of real-time monitoring and model prediction, and can perceive potential overheating risks in advance.

[0080] During the charging process, the temperature of the power battery will gradually rise due to internal chemical reactions and resistance heat generation. By real-time monitoring and calculating the heating rate, combined with the key factor of charging current, the future temperature state of the battery can be predicted more accurately, providing a scientific basis for timely activation of the cooling system.

[0081] This embodiment achieves the effect of predicting the temperature change trend of the power battery in advance, provides sufficient time for the cooling execution of the cooling component, and effectively reduces the risk of power battery damage caused by sudden temperature rise.

[0082] In one embodiment, Figure 3 As shown, step S102 includes:

[0083] Step S301: Calculate a target water temperature value according to the charging current value, the maximum battery core temperature value, the minimum battery core temperature value and the ambient temperature.

[0084] Step S302: Calculate the temperature difference between the cooling inlet water temperature value and the target water temperature value.

[0085] Step S303: determining the cooling power of the cooling assembly based on the temperature difference value, and causing the power battery to enter a cooling mode until the cooling inlet water temperature value is equal to the target water temperature value.

[0086] In this embodiment, the algorithm calculates the target water temperature value that can effectively balance the battery heat dissipation demand and the cooling system energy consumption through parameters such as the charging current value, the maximum battery cell temperature value, the minimum battery cell temperature value and the ambient temperature. Subsequently, by monitoring the deviation between the cooling inlet water temperature and the target water temperature, the working state of the cooling component is dynamically adjusted, including the opening of the electronic expansion valve, the speed of the electronic water pump, the coolant flow rate, etc., to achieve precise control of the cooling inlet water temperature value changing to the target water temperature value within a preset time.

[0087] The setting of the target water temperature value needs to comprehensively consider the battery heat dissipation requirements and the cooling system efficiency. Too high a water temperature may lead to poor cooling effect, while too low a water temperature will increase the energy consumption of the cooling system. Therefore, calculating the optimal target water temperature value through an algorithm and adjusting the working state of the cooling components accordingly is the key to achieving efficient cooling.

[0088] Specifically, the target water temperature value is calculated as follows:

[0089] T w =T p -α 2 (T max -T)-β 2 (T amb -T)

[0090] Among them, T wis the target water temperature, T p is the reference temperature value, α 2 is the third temperature coefficient, β 2 is the fourth temperature coefficient, T max is the maximum cell temperature, T amb is the ambient temperature, and T is the reference temperature. p , α 2 , β 2 and T are fixed values ​​obtained based on the characteristics and calibration of the power battery and cooling components. The designer can also change I p , α 2 , β 2 and the value of T. As an example, T p At 15°C, α 2 is 0.2, β 2 is 0.1, and T is 25.

[0091] By calculating the target water temperature value based on a comprehensive set of parameters, the control accuracy and efficiency of the cooling system can be improved to ensure that the power battery always remains within a safe and efficient temperature range during the charging process, while reducing the energy consumption of the cooling system.

[0092] In one embodiment, Figure 4 As shown, step S103 includes:

[0093] Step S401: calculating a maximum cell temperature difference value through the highest cell temperature value and the lowest cell temperature value, and judging whether the power battery meets a cell temperature difference excessive condition according to the maximum cell temperature difference value.

[0094] If the maximum temperature difference of the battery cells does not meet the condition that the temperature difference of the battery cells is too large, the target water temperature value is not changed.

[0095] If the maximum temperature difference value of the battery cells meets the condition that the temperature difference of the battery cells is too large, the target water temperature value is adjusted based on the maximum temperature difference value of the battery cells.

[0096] In this embodiment, by monitoring and calculating the maximum temperature difference between the cells, the uniformity of the temperature distribution inside the battery can be evaluated. When the maximum temperature difference exceeds the preset threshold, it indicates that there may be local overheating inside the battery. At this time, the target water temperature value needs to be adjusted according to the temperature difference to optimize the heat dissipation effect.

[0097] The temperature uniformity inside the battery has an important impact on its performance and life. Local overheating will not only lead to a decline in battery performance, but may also cause safety accidents. Therefore, dynamically adjusting the target water temperature value to cope with the situation of excessive temperature differences in the battery cells is an important measure to ensure the safe and stable operation of the battery.

[0098] The cooling system has enhanced its ability to regulate the temperature distribution inside the battery, effectively reducing the temperature difference between cells and improving the overall performance and life of the battery. At the same time, it has also further improved the reliability and safety of the power battery under complex working conditions.

[0099] Further, after step S401, the following steps are included:

[0100] Step S402: If the maximum temperature difference value of the battery cell is less than or equal to the first temperature difference threshold, it is determined that the power battery does not meet the condition of excessive temperature difference of the battery cell, and the target water temperature value is not changed.

[0101] Step S403: If the maximum temperature difference value of the battery cell is greater than the first temperature difference threshold and less than or equal to the second temperature difference threshold, it is determined that the power battery meets the condition of excessive temperature difference of the battery cell, and a temperature compensation value is calculated according to the maximum temperature difference value of the battery cell to be added to the target water temperature value.

[0102] Step S404: If the maximum temperature difference of the battery cell is greater than the second temperature difference threshold, it is determined that the power battery meets the condition of excessive temperature difference of the battery cell, and the target water temperature value is adjusted to the maximum cooling water temperature value allowed by the cooling component.

[0103] As a preferred method, the maximum temperature difference of the battery cell is calculated as follows:

[0104] T diff =T max -T min

[0105] Among them, T diff is the maximum temperature difference of the battery cell, T max is the maximum cell temperature, T min is the minimum cell temperature.

[0106] The temperature compensation value is calculated as:

[0107] T a =K*T diff

[0108] Among them, T a is the temperature compensation value, and K is the compensation coefficient obtained according to the calibration of the power battery or cooling component.

[0109] The target water temperature value is adjusted as follows:

[0110] T c =T w +T a

[0111] Among them, T c is the cooling inlet water temperature, T w is the target water temperature.

[0112] In this embodiment, when the temperature difference between the battery cells is too large, the present invention proposes two adjustment strategies. When the maximum temperature difference value of the battery cell is between the first temperature difference threshold and the second temperature difference threshold, the temperature compensation value method is adopted. The temperature compensation value is calculated based on the characteristics of the power battery and the maximum temperature difference value of the battery cell, taking into account multiple factors such as the temperature difference, battery thermal capacity, and cooling system response speed, and aims to gradually reduce the temperature difference between the battery cells by fine-tuning the target water temperature value.

[0113] When the maximum temperature difference of the battery cell exceeds the second temperature difference threshold, the system will take more radical measures and directly set the target water temperature value to the maximum cooling water temperature value allowed by the cooling component to maximize the cooling power, quickly reduce the battery temperature, and prevent the overheating situation from further deteriorating. After the maximum cooling water temperature value persists for a period of time, such as 2 minutes, re-judge whether the maximum temperature difference of the battery cell is less than or equal to the second temperature difference threshold. If the condition is met, clear the battery temperature difference mark and re-judge the temperature difference; if the condition is not met, continue to issue the battery temperature difference mark, and continue to use the maximum cooling water temperature value allowed by the cooling component as the cooling inlet water temperature value for cooling.

[0114] Excessive temperature difference in battery cells is an important challenge in battery thermal management. Too small an adjustment may not effectively improve the temperature distribution, while too large an adjustment may waste energy or cause other problems. Therefore, the present invention achieves precise control of the temperature difference of battery cells by introducing two strategies: temperature compensation value and maximum cooling water temperature value. The temperature compensation value strategy is suitable for situations with small temperature differences, and can reduce energy consumption while ensuring efficiency. The maximum cooling water temperature value strategy is suitable for emergency situations with extremely large temperature differences, and can quickly reduce the battery temperature to ensure battery safety.

[0115] This dynamic adjustment strategy not only improves the flexibility and response speed of the cooling system, but also ensures the best cooling effect under different temperature differences. It effectively reduces the temperature difference between cells, improves the overall performance and life of the battery, and also enhances the safety and reliability of the power battery under extreme working conditions.

[0116] In one embodiment, step S104 includes:

[0117] If the charging current value is continuously less than the charging current threshold value within the preset time, and the highest battery cell temperature value is less than or equal to the third temperature threshold value, it is determined that the power battery meets the cooling stop condition.

[0118] In this embodiment, a temperature detection interval is pre-set, and after cooling is turned on for a period of time, it is determined whether the power battery meets the cooling stop condition, so as to avoid continuous cooling to waste energy and the situation where the power battery temperature is too low. The third temperature threshold is a system preset value, or is calculated based on the temperature rise prediction of the power battery during high-rate charging. If the charging current value is continuously less than the charging current threshold within a preset time, for example, for 10 seconds, it proves that the power battery has exited the high-rate charging state, and it is determined whether the highest cell temperature value is less than or equal to the third temperature threshold. If all conditions are met at the same time, it can be determined that the temperature value of the power battery is no longer charged at a high rate and the cell temperature meets the safety range of normal operation. In the next temperature detection interval, it is not necessary to turn on the cooling component. At this time, the cooling component can be controlled to stop operating or operate at low power to make the power battery exit the cooling mode.

[0119] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0120] An embodiment of the present invention provides a cooling component for implementing the cooling control method of an automobile battery of any of the aforementioned embodiments, the cooling component includes a refrigeration circuit and a heat exchange circuit connected to a power battery, the refrigeration circuit and the heat exchange circuit are connected through a battery cooler, the refrigeration circuit includes a compressor, a condenser, a condenser fan, a battery cooler, an electronic expansion valve and a temperature and pressure sensor, and the heat exchange circuit includes an electronic water pump and a water temperature sensor.

[0121] An embodiment of the present invention provides a car, including a car body, in which a cooling assembly as described in the above embodiments is arranged, and the cooling assembly can implement all steps of the cooling control method of the car battery in any of the above embodiments.

[0122] like Figure 5 The figure shows a hardware structure diagram of an electronic device of the present invention, including a memory 502, a processor 501 and an electronic device program on the memory 502, and the processor 501 executes the electronic device program to implement the steps of the cooling control method of the automobile battery of any of the above embodiments.

[0123] Figure 5 A processor 501 is taken as an example.

[0124] The electronic device may further include: an input device 503 and a display device 504 .

[0125] The processor 501, the memory 502, the input device 503 and the display device 504 may be connected via a bus or other means, and the figure takes the connection via a bus as an example.

[0126] The memory 502 is a non-volatile electronic device readable storage medium, which can be used to store non-volatile software programs, non-volatile electronic device executable programs and modules, such as program instructions / modules corresponding to the cooling control method of the automotive battery in the embodiment of the present application. The processor 501 executes various functional applications and data processing by running the non-volatile software programs, instructions and modules stored in the memory 502, that is, implementing the cooling control method of the automotive battery in the above embodiment.

[0127] The memory 502 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required by at least one function; the data storage area may store data created according to the use of the cooling control method for the automotive battery, etc. In addition, the memory 502 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 502 may optionally include a memory remotely arranged relative to the processor 501, and these remote memories may be connected to a device for executing the cooling control method for the automotive battery via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0128] The input device 503 may receive a user click input, and generate a signal input related to the user setting and function control of the cooling control method of the automobile battery. The display device 504 may include a display device such as a display screen.

[0129] The one or more modules are stored in the memory 502 , and when executed by the one or more processors 501 , the cooling control method for a vehicle battery in any of the above method embodiments is executed.

[0130] When the electronic device disclosed in the present invention is in operation, it can execute all the steps of the above-mentioned automotive battery cooling control method, comprehensively judge whether cooling needs to be turned on through the ambient temperature and battery status information, and dynamically adjust the cooling strategy through the battery status change after cooling is turned on, so as to realize the early start and precise control of power battery cooling, avoid a sharp rise in power battery temperature, speed up the charging efficiency of the power battery and extend the service life of the power battery, so that the temperature control capability of the power battery can meet the needs of high-rate charging.

[0131] An embodiment of the present invention provides an electronic device readable storage medium, which stores an electronic device program / instruction. When the electronic device program / instruction is executed by the processor 501, all steps of the above-mentioned automotive battery cooling control method are implemented.

[0132] In the context of the present disclosure, a storage medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or apparatus. The storage medium may be a machine-readable signal medium or a machine-readable storage medium. Alternatively, the storage medium may be a non-temporary electronic device readable storage medium, for example, a non-temporary electronic device readable storage medium may be a ROM, a random access memory (Random Access Memory, RAM), a compact disc read-only memory (Compact Disc ROM, CD-ROM), a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0133] An embodiment of the present invention provides an electronic device program product, including an electronic device program / instruction, which implements the steps of the above-mentioned automotive battery cooling control method when executed by a processor.

[0134] By running the above-mentioned electronic device program product, all steps of the cooling control method for the automobile battery as described above can be executed, and whether cooling needs to be turned on can be comprehensively judged through the ambient temperature and battery status information. After cooling is turned on, the cooling strategy can be dynamically adjusted according to the change of battery status to realize early start and precise control of power battery cooling, avoid a sharp rise in power battery temperature, speed up the charging efficiency of the power battery and extend the service life of the power battery, so that the temperature control capability of the power battery can meet the needs of high-rate charging.

[0135] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A cooling control method for a vehicle battery, characterized in that: include: Determine whether the power battery meets the cooling start condition according to the ambient temperature and battery status information; If the power battery meets the cooling start-up condition, controlling the cooling component to operate so that the power battery enters a cooling mode; Dynamically adjusting the cooling strategy of the cooling component according to the change of the battery status information in the cooling mode; If the power battery meets the cooling stop condition, the cooling component is controlled to operate to make the power battery exit the cooling mode.

2. The cooling control method for a vehicle battery according to claim 1, characterized in that: The determining whether the power battery meets the cooling start condition according to the ambient temperature and the battery status information includes: If the power battery is in a charging state, the power battery is tested; The charging current value, the maximum cell temperature value, the minimum cell temperature value and the cooling inlet water temperature value of the power battery are measured respectively and combined to generate battery status information; If the maximum battery cell temperature value is greater than or equal to the first temperature threshold, it is determined that the power battery meets the cooling start condition; If the charging current value is continuously greater than or equal to the charging current threshold value within a preset time, and the lowest battery cell temperature value is greater than or equal to the second temperature threshold value, it is determined that the power battery meets the cooling start-up condition.

3. The cooling control method of the automobile battery according to claim 2, characterized in that: The charging current threshold is obtained by calculating the difference between the maximum battery cell temperature value and the reference temperature value, the difference between the ambient temperature and the reference temperature value, and the characteristic parameters of the power battery.

4. The cooling control method for a vehicle battery according to claim 2, characterized in that: The step of judging whether the power battery meets the cooling start condition according to the ambient temperature and the battery status information further includes: The temperature value of each battery cell is collected at intervals within a preset time, and the heating rate of each battery cell is calculated respectively; Calculating a temperature change trend of the power battery based on the charging current value and the temperature rise rate; If the temperature change trend meets the rapid temperature rise condition, it is determined that the power battery meets the cooling start condition.

5. The cooling control method for a vehicle battery according to claim 2, characterized in that: The controlling the cooling component to operate so that the power battery enters a cooling mode includes: Calculate a target water temperature value according to the charging current value, the maximum battery core temperature value, the minimum battery core temperature value and the ambient temperature; Calculating the temperature difference between the cooling inlet water temperature value and the target water temperature value; The cooling power of the cooling assembly is determined based on the temperature difference value, so that the power battery enters a cooling mode until the cooling inlet water temperature value is equal to the target water temperature value.

6. The cooling control method for a vehicle battery according to claim 5, characterized in that: The dynamically adjusting the cooling strategy of the cooling component according to the change of the battery status information in the cooling mode includes: Calculating a maximum cell temperature difference value by using the maximum cell temperature value and the minimum cell temperature value, and judging whether the power battery meets a cell temperature difference excessive condition according to the maximum cell temperature difference value; If the maximum temperature difference of the battery cell does not meet the condition that the temperature difference of the battery cell is too large, the target water temperature value is not changed; If the maximum temperature difference value of the battery cells meets the condition that the temperature difference of the battery cells is too large, the target water temperature value is adjusted based on the maximum temperature difference value of the battery cells.

7. The cooling control method for a vehicle battery according to claim 6, characterized in that: The determining, according to the maximum temperature difference value of the battery cells, whether the power battery meets the condition of excessive temperature difference of the battery cells includes: If the maximum temperature difference value of the battery cell is less than or equal to the first temperature difference threshold, it is determined that the power battery does not meet the condition of excessive temperature difference of the battery cell, and the target water temperature value is not changed; If the maximum temperature difference of the battery cell is greater than the first temperature difference threshold and less than or equal to the second temperature difference threshold, it is determined that the power battery meets the condition of excessive temperature difference of the battery cell, and a temperature compensation value is calculated according to the maximum temperature difference of the battery cell to be added to the target water temperature value; If the maximum temperature difference of the battery cell is greater than the second temperature difference threshold, it is determined that the power battery meets the condition of excessive temperature difference of the battery cell, and the target water temperature value is adjusted to the maximum cooling water temperature value allowed by the cooling component.

8. The cooling control method for a vehicle battery according to claim 2, characterized in that: If the power battery meets the cooling stop condition, controlling the cooling component to operate so that the power battery exits the cooling mode includes: If the charging current value is continuously less than the charging current threshold value within a preset time, and the highest battery cell temperature value is less than or equal to a third temperature threshold value, it is determined that the power battery meets the cooling stop condition.

9. A cooling assembly for implementing the cooling control method of a vehicle battery as claimed in any one of claims 1 to 8, characterized in that: It includes a refrigeration circuit and a heat exchange circuit connected to the power battery. The refrigeration circuit and the heat exchange circuit are connected through a battery cooler. The refrigeration circuit includes a compressor, a condenser, a condenser fan, a battery cooler, an electronic expansion valve and a temperature and pressure sensor. The heat exchange circuit includes an electronic water pump and a water temperature sensor.

10. A car, comprising a car body, characterized in that: The automobile body is provided with a cooling assembly as claimed in claim 9, and the cooling assembly can implement the steps of the cooling control method for the automobile battery as claimed in any one of claims 1 to 8.

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