Mobile device, charging control method and chip

Abstract

The invention provides a mobile device, a charging control method and a chip, and relates to the technical field of electronics. The charging control method is applied to the mobile device, the mobile device is used for being connected with a charging pile to form a charging system, and the charging pile is used for charging a battery cell of the mobile device. The method comprises the following steps: detecting the temperature of a battery cell; if the temperature of the battery cell is equal to the target temperature, the heating function of the battery cell is closed until charging is finished, and the temperature change of the battery cell is in positive correlation with the internal resistance of the battery cell and the charging current provided by the charging pile. According to the scheme, rapid charging of the battery cell can be realized.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of electric vehicle charging, and more particularly to a mobile device, a charging control method, and a chip. Background Art

[0002] With the increasing energy shortage and environmental pollution in modern society, electric vehicles as new energy vehicles have attracted wide attention from all walks of life. Electric vehicles use power batteries as energy to drive the vehicle. With the improvement of vehicle performance and the acceleration of the pace of life, users are more sensitive to charging time.

[0003] However, the power battery cell has a characteristic that the battery capacity and charge and discharge speed will decrease as the ambient temperature decreases within a certain temperature range; and when the temperature exceeds this temperature range, the charge and discharge speed will drop sharply. Based on this characteristic, when charging the battery cell, in order to ensure the shortest charging time and battery cell safety, it is usually necessary to perform thermal management on the power battery pack (for example, in a scenario with a low ambient temperature, heating to increase the charge and discharge speed; or, in order to avoid triggering the current limiting temperature, cooling the battery cell to ensure battery cell safety) in order to give full play to the energy storage and charge and discharge capabilities of the power battery pack.

[0004] However, repeated thermal management will also consume a certain amount of time, so how to achieve fast charging of battery cells becomes a problem that needs to be solved. Summary of the invention

[0005] The embodiments of the present application provide a mobile device, a charging control method and a chip, which can realize fast charging of a battery cell while saving energy as much as possible.

[0006] In the first aspect, a charging control method is provided, which is applied to a mobile device, wherein the mobile device is used to connect to a charging pile to form a charging system, and the charging pile is used to charge the battery cell of the mobile device. The method includes: detecting the temperature of the battery cell; if the temperature of the battery cell is equal to the target temperature, turning off the heating function of the battery cell until the charging is completed, and the temperature change of the battery cell is positively correlated with the internal resistance of the battery cell and the charging current provided by the charging pile. In this way, first, after the temperature of the battery cell reaches a higher level of the target temperature, the heating function of the battery cell can be turned off. During the charging process of the battery cell, the charging current will consume heat on the internal resistance of the battery cell to maintain the temperature of the battery cell, and the temperature of the battery cell will be heated by the heat generated by the internal resistance and rise, which is conducive to increasing the charging speed of the battery cell and realizing fast charging of the battery cell.

[0007] In a possible implementation, if the temperature of the battery cell is not equal to the target temperature, that is, before the temperature of the battery cell is equal to the target temperature, it also includes: turning on the thermal management function of the battery cell until the temperature of the battery cell is equal to the target temperature, and the thermal management function includes a heating function or a cooling function. Specifically, if the temperature of the battery cell of the electric vehicle does not reach the target temperature when the charging pile starts to charge the battery cell, in order to increase the charging speed, the heating function of the battery cell can be turned on when the charging pile starts to charge the battery cell or before charging starts, until the temperature of the battery cell is greater than or equal to the target temperature. For another example, when the charging pile starts to charge the battery cell, the temperature of the battery cell of the electric vehicle is greater than the target temperature, then the current limiting temperature may be triggered in the subsequent charging process, causing the charging current to drop sharply and reducing the charging speed. Therefore, in order to avoid triggering the current limiting temperature and increase the charging speed, the cooling function of the battery cell can be turned on when the charging pile starts to charge the battery cell or before charging starts, until the temperature of the battery cell is equal to the target temperature.

[0008] In a possible implementation, after the heating function of the battery cell is turned off, the cooling function of the battery cell is kept turned off during the charging process of the battery cell. In this way, the energy consumption can be further reduced by not cooling the battery cell.

[0009] In one possible implementation, in order to avoid the temperature being too high during charging triggering thermal current limiting and causing a decrease in charging speed, it is necessary to turn on the cooling function in advance before the current limiting temperature is reached. Therefore, after turning off the heating function of the battery cell, if it is determined that the temperature of the battery cell is greater than or equal to the first temperature, where the first temperature is lower than the current limiting temperature, the refrigeration function is turned on to cool the battery cell, thereby ensuring the safety of the power battery.

[0010] In a possible implementation, the method further includes: obtaining the state of charge (SOC) of the battery cell; determining the target temperature according to the SOC and the target temperature rise curve; wherein the distance between the target temperature and the target temperature rise curve is less than or equal to a predetermined error value, the abscissa of the target temperature rise curve is the SOC, and the ordinate of the target temperature rise curve is the temperature. In this way, the target temperature can be determined by searching the target temperature rise curve according to the SOC of the battery cell.

[0011] In a possible implementation, after the heating function of the battery cell is turned off, at any state of charge, the distance between the temperature of the battery cell and the target temperature rise curve is less than or equal to a predetermined error value, the abscissa of the target temperature rise curve is the state of charge, and the ordinate of the target temperature rise curve is the temperature. In this way, when the heating function of the battery cell is turned off, the temperature of the battery cell gradually rises according to the target temperature rise curve, thereby ensuring the charging speed.

[0012] In a possible implementation, the method further includes: obtaining the ambient temperature; determining the target temperature rise curve according to the ambient temperature; wherein, under the same state of charge, the temperature on the target temperature rise curve is negatively correlated with the ambient temperature. For example, the higher the ambient temperature, the lower the temperature on the target temperature rise curve. In this way, temperature compensation can be performed according to the impact of the ambient temperature on the target temperature rise curve, thereby reducing the impact of the ambient temperature on the charging speed of the battery cell.

[0013] In one possible implementation, the temperature on the target temperature rise curve is positively correlated with the state of charge SOC of the battery cell, that is, after turning off the heating function, the temperature of the battery cell gradually increases with the increase of SOC during the charging process, thereby ensuring the charging speed of the battery cell.

[0014] In a possible implementation, the target temperature rise curve is determined according to the maximum charging current of the charging pile.

[0015] In a possible implementation, the target temperature rise curve is determined according to the maximum charging current of the charging pile, including: in the charged state, if the temperature of the battery cell corresponding to the maximum charging current of the charging pile is greater than the temperature on the first temperature rise curve, then the first temperature rise curve is used as the target temperature rise curve; the horizontal coordinate of the first temperature rise curve is the charged state, and the vertical coordinate of the first temperature rise curve is the temperature; in the charged state, if the temperature of the battery cell corresponding to the maximum charging current of the charging pile is less than the temperature on the first temperature rise curve, then the second temperature rise curve is used as the target temperature rise curve, the horizontal coordinate of the second temperature rise curve is the charged state, and the vertical coordinate of the second temperature rise curve is the temperature; in the charged state, the temperature on the second temperature rise curve is less than the temperature on the first temperature rise curve. Wherein, when the capacity of the charging pile is large enough, that is, the maximum charging current provided by the charging pile is greater than or equal to the charging current allowed to be charged under all conditions of the power battery, an ideal first temperature rise curve can be measured experimentally for the power battery used as the target temperature rise curve. When the capacity of the charging pile is limited, that is, the maximum charging current provided by the charging pile is less than the charging current allowed to be charged under certain conditions of the power battery, another second temperature rise curve can be obtained as the target temperature rise curve according to the capacity of the charging pile.

[0016] In a possible implementation, under the same state of charge, the maximum charging current of the charging pile is positively correlated with the temperature of the battery cell. In this way, when the maximum charging current of the charging pile is limited, the target temperature can be heated to a lower battery cell temperature; when the maximum charging current of the charging pile is high, the battery cell needs to be heated to a higher temperature, which can reduce the energy consumed by heating the battery cell.

[0017] In one possible implementation, obtaining the state of charge of the battery cell specifically includes: obtaining navigation information, determining the state of charge of the battery cell when navigating to the charging pile according to the navigation information; then, controlling the activation of the thermal management function of the battery cell according to the state of charge of the battery cell, heating or cooling the battery cell to a target temperature before navigating to the charging pile, and the thermal management function includes a heating function or a cooling function. In this scheme, by obtaining navigation information, the temperature of the battery cell can be heated (cooled) to a target temperature in a target temperature rise curve through thermal management before the mobile device reaches the charging pile. In this way, since the battery cell is pre-heated before navigating to the charging pile, the impact of thermal management of the battery cell on the charging time during the charging process is reduced.

[0018] In a possible implementation, obtaining the state of charge of the battery cell specifically includes: obtaining the state of charge of the battery cell after the charging pile charges the battery cell of the mobile device; then, controlling the activation of a thermal management function for the battery cell according to the state of charge of the battery cell until the battery cell is heated or cooled to a target temperature, wherein the thermal management function includes a heating function or a cooling function. In this solution, the battery cell can also be thermally managed to a target temperature while charging.

[0019] In a second aspect, a charging control device is provided, which is applied to a mobile device, and may be the mobile device itself or a chip or chip system disposed in the mobile device. The mobile device is used to connect to a charging pile to form a charging system, and the charging pile is used to charge the battery cell of the mobile device; the charging control device includes: a processor and a memory coupled to the processor; the memory stores program code, and the processor is used to execute the program code in the memory to execute the charging control method provided by the first aspect and its possible implementation.

[0020] In a third aspect, a chip is provided, comprising the charging control device as described in the second aspect and possible implementations thereof.

[0021] In a fourth aspect, a mobile device is provided, comprising a battery cell and a charging control device as described in the third aspect and possible implementations thereof, connected to the battery cell.

[0022] In a fifth aspect, a charging system is provided, including a mobile device and a charging pile, wherein the mobile device includes the mobile device of the fourth aspect and possible implementations thereof.

[0023] Among them, the technical problems solved by the second to fifth aspects and their possible implementation methods and the technical effects achieved can be referred to the description in the first aspect and its possible implementation methods, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of a charging system provided in an embodiment of the present application;

[0025] Figure 2 A schematic diagram of the structure of a charging control device provided in an embodiment of the present application;

[0026] Figure 3 A schematic flow chart of a charging control method provided in an embodiment of the present application;

[0027] Figure 4 A schematic diagram of the architecture of a charging system provided in an embodiment of the present application;

[0028] Figure 5 A schematic flow chart of a charging control method provided in another embodiment of the present application;

[0029] Figure 6 A schematic diagram of a charging control method provided for another embodiment of the present application;

[0030] Figure 7 A schematic flow chart of a charging control method provided for yet another embodiment of the present application;

[0031] Figure 8 A schematic diagram of the structure of a charging control device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] The embodiments of the present application provide a mobile device, a charging control method and a chip. The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of them. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0033] The scheme disclosed in the embodiments of the present application can be applied to mobile devices using power batteries as power energy sources, and is particularly suitable for mobile devices using lithium-ion power batteries as power energy sources. Among them, the mobile device can be an intelligent device using a power battery, including but not limited to: smart home devices, such as TVs, sweeping robots, smart desk lamps, audio systems, smart lighting systems, electrical control systems, home background music, home theater systems, intercom systems, video surveillance, etc.; intelligent transportation equipment, such as electric cars, electric ships, electric drones, electric trains, electric trucks, electric trucks, etc.; intelligent manufacturing equipment, such as robots, industrial equipment, intelligent logistics, smart factories, etc. Alternatively, the mobile device can also be a computer device using a power battery, such as a desktop, a personal computer, a server, etc. It should also be understood that the mobile device can also be a portable electronic device using a power battery, such as a mobile phone, a tablet computer, a PDA, a headset, an audio device, a wearable device (such as a smart watch), a vehicle-mounted device, a virtual reality device, an augmented reality device, etc. Examples of portable electronic devices include but are not limited to portable electronic devices equipped with or other operating systems. The above-mentioned portable electronic device can also be a laptop computer (Laptop) with a touch-sensitive surface (such as a touch panel). The following examples mainly use electric vehicles as an example.

[0034] In a specific application scenario, the solution disclosed in the embodiments of the present application can be applied to electric vehicles, which are also called new energy vehicles and are vehicles driven by electric energy. Figure 1As shown, it is a schematic diagram of a charging system for an electric vehicle provided in an embodiment of the present application. The charging system of the electric vehicle shown includes an electric vehicle 10 and a charging pile 20. Among them, the electric vehicle 10 mainly includes a battery cell 101, a battery management system 103 (battery management system, BMS) and a thermal management system 102 (thermal management system, TMS). Among them, the battery cell 101 of the electric vehicle 10 can be charged by the charging pile 20 (for example, the battery management system 103 can include a charging circuit for charging the battery cell 101, and the charging pile 20 can charge the battery cell 101 through the charging circuit), and the battery cell 101 is thermally managed by the thermal management function of the thermal management system 102, for example, the battery cell 101 is heated (cooled) by the heating function (cooling function). In addition, the voltage, current, temperature and other parameters of the battery cell 101 can also be detected by the battery management system 103, and a thermal management request can be sent to the thermal management system 102 according to the detected parameters to turn on or off the thermal management function (heating function or cooling function) of the thermal management system 102. In some examples, the charging pile 20 inputs charging current to the battery cell 101 and the thermal management system 102 according to the demand current instruction output by the battery management system 103 and the current of the charging pile 20 itself. The battery management system 103 determines the current state of the battery cell 101 according to the detected battery voltage, current and temperature, and requests corresponding thermal management. The thermal management system 102 receives the thermal management request output by the battery management system 103 and performs heating, cooling and other processing on the battery cell 101. Figure 1 Also shown is a typical structure of a thermal management system 102, which includes a passage for passing coolant, the passage includes a battery heat dissipation channel, a pump, a positive temperature coefficient (PTC) heater and a refrigerator, wherein a refrigerant is introduced into the refrigerator to cool the coolant through heat exchange with the coolant (i.e., realize the cooling function); the PTC can heat the coolant (i.e., realize the heating function); the battery cell 101 is directly in contact with the battery heat dissipation channel, and the pump drives the coolant to circulate in the battery heat dissipation channel, thereby taking away the heat of the battery cell 101 to cool the battery cell 101 (cooling down), or providing heat to the battery cell 101 to heat the battery cell 101 (heating up).

[0035] Generally, the charging time of electric vehicles has always been one of the main indicators that consumers consider when purchasing a vehicle. The charging speed of electric vehicles is closely related to the charging current allowed to be charged into the battery cell 101. The charging current allowed to be charged into the battery cell 101 is closely related to the temperature and state of charge (SOC) of the battery cell 101 in the power battery. Usually, the battery management system 103 controls the thermal management system 102 to adjust the temperature of the coolant to affect the temperature of the battery cell 101, thereby changing the charging current allowed to be charged into the battery cell 101.

[0036] In a battery cell scenario of a test specification, the measured battery cell temperature, SOC and charging rate (charging rate * battery capacity, that is, the charging current provided by the charging pile) constitute a charging rate map, as shown in Table 1 below.

[0037]

[0038]

[0039] Table 1

[0040] Combined with the above Table 1, it can be seen that for power batteries, the allowed charging current is usually larger when the cell temperature is usually between 20 and 40°C, and the higher the temperature in this range, the greater the allowed charging current. Therefore, when charging in a low temperature environment, the cell is usually preheated or heated during the charging process to achieve a faster charging speed. However, since the cell temperature reaches a higher temperature (such as 45°C), the allowed charging current will be significantly reduced. Therefore, in order to avoid triggering the current limiting temperature, the cell is usually cooled when the cell temperature is lower than the current limiting temperature.

[0041] At present, the mainstream thermal management method during charging is to set a threshold for the heating temperature, and the threshold is a fixed hysteresis range. For example, when the temperature is lower than 15°C, the heating function is activated, and when it is higher than 18°C, the heating function is deactivated. However, since repeated thermal management takes a certain amount of time, how to achieve fast charging of the battery cell becomes a problem that needs to be solved.

[0042] The embodiments of the present application perform thermal management on the battery cells before the charging pile charges the battery cells or after the charging is started until the battery cells reach the target temperature. After the temperature of the battery cells reaches the target temperature, which is a higher level, the heating function of the battery cells can be turned off. During the charging process of the battery cells, the charging current provided by the charging pile will consume heat on the internal resistance of the battery cells to maintain the temperature of the battery cells, and the temperature of the battery cells will be heated by the heat generated by the internal resistance, which is beneficial to increase the charging speed of the battery cells and realize fast charging of the battery cells.

[0043] Figure 2is a schematic diagram of a charging control device provided in an embodiment of the present application. The charging control device 200 may be the battery management system 103 provided in the above embodiment or applied to a vehicle control unit (VCU); the charging control device 200 includes a processor 201 and a memory 202 coupled to the processor 201, the memory 202 is used to store a program code of a charging control method provided in an embodiment of the present application; the processor 201 is used to execute the program code stored in the memory. The charging control device 200 can implement the charging control method provided in each embodiment of the present application through the processor 201 and the program code in the memory 202.

[0044] The above-mentioned processor can be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or can be one or more integrated circuits used to control the execution of the program of the present application.

[0045] The above-mentioned memory can be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, or a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited to this.

[0046] Next, the charging control method provided in the embodiment of the present application is described. Figure 3 This is a flow chart of a charging control method provided in an embodiment of the present application. The method can be applied to a charging control device in an electric vehicle, such as a battery management system BMS, a vehicle controller VCU, etc. of an electric vehicle. An electric vehicle is used to connect a charging pile to form a charging system, and the charging pile is used to charge the battery cells of the electric vehicle.

[0047] S101. A charging control device detects the temperature of a battery cell.

[0048] Among them, step S101 can be specifically that the battery management system BMS detects the temperature of the battery cell. Of course, it can be understood that the battery management system BMS can detect the temperature of the battery cell at any time. In step S101, the temperature detection of the battery cell can be triggered by the charging connection established between the charging pile and the electric vehicle, that is, the temperature detection can be performed when the charging pile starts to charge the battery cell or when the charging pile starts to charge the battery cell. Specifically, the temperature T of the battery cell can be detected by the charging control device.

[0049] S102 . If the temperature of the battery cell is equal to the target temperature T_target, turn off the heating function of the battery cell until charging is completed. The temperature change of the battery cell is positively correlated with the internal resistance of the battery cell and the charging current provided by the charging pile.

[0050] Of course, in some examples, before the temperature of the battery cell is equal to the target temperature T_target, that is, if the temperature of the battery cell is not equal to the target temperature, it also includes: turning on the thermal management function of the battery cell until the temperature of the battery cell is equal to the target temperature T_target, and the thermal management function includes a heating function or a cooling function. Specifically, if the temperature of the battery cell of the electric vehicle does not reach the target temperature T_target when the charging pile starts to charge the battery cell, in order to increase the charging speed, the heating function of the battery cell can be turned on when the charging pile starts to charge the battery cell or before charging starts, until the temperature of the battery cell is equal to the target temperature T_target. For another example, when the charging pile starts to charge the battery cell, the temperature of the battery cell of the electric vehicle is greater than the target temperature T_target, then the current limiting temperature may be triggered in the subsequent charging process, causing the charging current to drop sharply and reducing the charging speed. Therefore, in order to avoid triggering the current limiting temperature and increase the charging speed, the cooling function of the battery cell can be turned on when the charging pile starts to charge the battery cell or before charging starts, until the temperature of the battery cell is equal to the target temperature T_target.

[0051] Among them, the positive correlation in the above text is used to represent a relationship between parameter A and parameter B. When parameters A and B are positively correlated, it means that parameter A increases as parameter B increases. Among them, one form of positive correlation is positive proportional correlation. When parameters A and B are positively correlated, the increase of parameter A and parameter B is linearly related. Correspondingly, in the description below, negative correlation means that parameter A decreases as parameter B increases.

[0052] In some examples, before step S102, the process also includes: obtaining the state of charge of the battery cell; determining the target temperature T_target according to the state of charge and the target temperature rise curve; wherein the distance between the target temperature T_target and the target temperature rise curve is less than or equal to a predetermined error value, the horizontal coordinate of the target temperature rise curve is the state of charge SOC, and the vertical coordinate of the target temperature rise curve is the temperature.

[0053] Among them, in the following scheme, according to the different capabilities of the charging pile, the target temperature rise curve can also be determined according to the maximum charging current of the charging pile. In the following scheme, two methods of determining the target temperature rise curve are mainly provided:

[0054] Among them, when the capacity of the charging pile is large enough, that is, the charging current provided by the charging pile is greater than or equal to the charging current allowed to be charged under all conditions of the power battery (the temperature and SOC of the battery cell in Table 1), an ideal target temperature rise curve (first temperature rise curve) can be measured experimentally for the power battery used, as shown in Table 2 below.

[0055]

[0056] Table 2

[0057] Under the target temperature rise curve, the temperature T_optimal corresponding to the battery cell in the SOC range can be obtained. In this way, according to the actual SOC size of the battery cell during the charging process, the corresponding target temperature T_target is near the target temperature rise curve (T_target≈T_optimal). When the temperature of the detected battery cell meets the temperature T_optimal corresponding to the target temperature rise curve in a certain SOC range, the heating function can be turned off in the subsequent charging process, and the temperature change of the battery cell is positively correlated with the internal resistance of the battery cell and the charging current provided by the charging pile. In addition, after turning off the heating function of the battery cell, at any state of charge SOC, the distance between the temperature of the battery cell and the target temperature rise curve is less than or equal to the predetermined error value. In this way, when the heating function of the battery cell is turned off, the temperature of the battery cell gradually rises according to the target temperature rise curve, ensuring the charging speed.

[0058] In addition, the above Table 2 is a target temperature rise curve provided when the charging pile capacity is not limited. In some examples, when the charging pile capacity is limited, that is, the charging current provided by the charging pile is less than the charging current allowed to be charged under certain conditions of the power battery (the temperature and SOC of the battery cell in Table 1), Table 1 can be queried according to the capacity of the charging pile to obtain another target temperature rise curve (the second temperature rise curve). Referring to Table 3, the target temperature rise curve is determined by the maximum charging current of the charging pile, that is, the second temperature rise curve is a temperature rise curve measured based on full utilization of the charging pile capacity.

[0059] Temperature / SOC 5％ 10％ 15％ 20％ 25％ 30％ 35％ 40％ 45％ 50％ 55％ 60％ 65％ 70％ 75％ 80％ T_pilecurrent / 10 15 15 15 20 20 25 25 30 30 40 40 / / /

[0060] Table 3

[0061] Among them, by comparing Table 2 and Table 3, it can be concluded that under the same state of charge SOC, the maximum charging current of the charging pile is positively correlated with the temperature of the battery cell. That is, the capacity of the charging pile in Table 2 is greater than the capacity of the charging pile in Table 3, then under the same SOC (for example, 10%), the temperature T_pilecurrent of the battery cell in Table 3 is less than the temperature T_optimal of the battery cell in Table 2. In this way, when the maximum charging current of the charging pile is limited, the target temperature can be heated to a lower battery cell temperature, thereby reducing the energy consumed by heating the battery cell when the maximum charging current of the charging pile is high and the battery cell needs to be heated to a higher temperature.

[0062] Based on the above-mentioned Tables 2 and 3, the method of determining the target temperature rise curve includes: in the state of charge, if the temperature T_pilecurrent of the battery cell corresponding to the maximum charging current of the charging pile (which can be obtained by looking up Table 1) is greater than the temperature T_optimal on the first temperature rise curve (which can be obtained by looking up Table 2), then the first temperature rise curve is used as the target temperature rise curve; the abscissa of the first temperature rise curve is the state of charge, and the ordinate of the first temperature rise curve is the temperature; in the state of charge, if the temperature T_pilecurrent of the battery cell corresponding to the maximum charging current of the charging pile (which can be obtained by looking up Table 1) is less than the temperature T_optimal on the first temperature rise curve, then the second temperature rise curve is used as the target temperature rise curve, the abscissa of the second temperature rise curve is the state of charge, and the ordinate of the second temperature rise curve is the temperature; in the target state of charge, the temperature T_pilecurrent on the second temperature rise curve (which can be obtained by looking up Table 3, at this time the temperature on the second temperature rise curve, that is, the temperature of the battery cell corresponding to the maximum charging current of the charging pile) is less than the temperature T_optimal on the first temperature rise curve.

[0063] In addition, the temperature on the target temperature rise curve is positively correlated with the state of charge SOC of the battery cell. That is, after turning off the heating function, the temperature of the battery cell gradually rises with the increase of SOC during the charging process, thereby ensuring the charging speed of the battery cell. In addition, in order to reduce the impact of ambient temperature, it also includes: obtaining the ambient temperature; determining the target temperature rise curve according to the ambient temperature; under the same state of charge, the temperature on the target temperature rise curve is negatively correlated with the ambient temperature. For example, the higher the ambient temperature, the lower the temperature on the target temperature rise curve. In this way, temperature compensation can be performed on the impact of the ambient temperature and the target temperature rise curve, reducing the impact of the ambient temperature on the charging speed of the battery cell.

[0064] In this way, first, after the temperature of the battery cell reaches the target temperature, which is a higher level, the heating function of the battery cell can be turned off. During the charging process of the battery cell, the charging current will consume heat on the internal resistance of the battery cell to maintain the temperature of the battery cell, and the temperature of the battery cell will be heated by the heat generated by the internal resistance, which is beneficial to increase the charging speed of the battery cell and realize fast charging of the battery cell.

[0065] In addition, after turning off the heating function of the battery cell, when the temperature of the battery cell rises according to the above-mentioned target temperature rise curve, the cooling function of the battery cell is not turned on during the charging process of the battery cell. In this way, there is no need to refrigerate the battery cell, which can further reduce energy consumption. Of course, in order to avoid the temperature being too high during charging, triggering thermal current limiting and causing the charging speed to decrease, it is necessary to turn on the cooling function in advance before the current limiting temperature is reached. Therefore, after turning off the heating function of the battery cell, if it is determined that the temperature of the battery cell is greater than or equal to the first temperature, the cooling function is turned on to cool the battery cell, and the first temperature is less than the current limiting temperature. Thereby ensuring the safety of the power battery.

[0066] In the following schemes, specific processes of charging control methods for two different application scenarios are provided respectively:

[0067] Scenario 1: By obtaining navigation information, the temperature of the battery cell can be heated (cooled) to the target temperature in the target temperature rise curve through thermal management before the mobile device reaches the charging station.

[0068] Reference Figure 4 As shown, when a user uses the navigation system of the electric vehicle 10 to navigate to a charging station, the BMS recognizes the user's charging demand based on the navigation information provided by the navigation system, and determines the state of charge SOC of the battery cell when navigating to the charging pile based on the navigation information; according to the state of charge SOC of the battery cell, the thermal management function (heating function or cooling function) of the battery cell is turned on, and the battery cell is heated (or cooled) to the target temperature before navigating to the charging pile to achieve faster charging speed.

[0069] Specific, combined Figure 4 and Figure 5 As shown, first, in step 301, the BMS of the electric vehicle recognizes the user's charging demand based on the navigation information provided by the navigation system; in step 302, the BMS of the electric vehicle can Figure 2The memory (202) therein obtains the capabilities of the destination charging pile, determines the maximum charging current Ipile that it can output, estimates the SOC upon arrival at the charging pile (considering the hysteresis of the cell temperature adjustment by the thermal management function, it can be taken to the right. For example, when the estimated SOC is 12%, it can be taken to 15% to the right for convenient table lookup), and obtains the temperature T_pilecurrent of the cell that can fully utilize the capabilities of the charging pile through Table 1 based on Ipile and SOC. Meanwhile, in step 303, according to the estimated SOC upon arrival at the charging station (which can be taken to the right), the temperature T_optimal corresponding to the target temperature rise curve (the first temperature rise curve) is obtained through Table 2. The capabilities of the charging pile can be recorded after the electric vehicle has established a connection with the destination charging pile during previous charging processes, and the BMS of the electric vehicle can store the mapping relationship established between the navigation information and the capabilities of the charging pile in the database for future query.

[0070] After that, since the capabilities of the charging piles at different destinations are different, the relative magnitude relationship between T_optimal and T_pilecurrent can be divided into two major categories. Finally, in step 304, the BMS detects the current temperature T of the cell, and performs thermal management control on the cell according to the relationship among T, T_optimal, and T_pilecurrent, as shown in Figure 6 as follows:

[0071] 1) T_optimal < T_pilecurrent

[0072] ① T < T_optimal < T_pilecurrent: The temperature T of the cell is lower than T_optimal. To achieve a faster charging speed by further heating, the heating target temperature T_target = T_optimal is determined according to the first temperature rise curve.

[0073] ② T_optimal < T < T_pilecurrent, or T_optimal < T_pilecurrent < T: The temperature T of the cell is higher than T_optimal. In the later stage of charging, it may exceed the current-limiting temperature and affect the charging speed. Therefore, the cell needs to be cooled, and the cooling target temperature T_target = T_optimal is determined according to the first temperature rise curve.

[0074] 2) T_pilecurrent < T_optimal

[0075] ①T < T_pilecurrent < T_optimal: The temperature T of the battery cell is lower than T_pilecurrent, and T_pilecurrent is lower than T_optimal. Therefore, it is necessary to heat the battery cell to further fully utilize the capacity of the charging pile. According to the second temperature rise curve, the heating target temperature T_target = T_pilecurrent is determined.

[0076] ②T_pilecurrent < T < T_optimal, or T_pilecurrent < T_optimal < T: This indicates that the capacity of the charging pile can already be fully utilized and will be limited by the capacity of the charging pile. There is no need to activate the thermal management function and no processing is performed.

[0077] In addition, on the way when the user navigates to the charging station, since the user's road conditions may change, the state of charge SOC of the battery cell can be periodically estimated based on the arrival at the charging station, and thus the target temperature T_target can be periodically refreshed (for example, refreshed once every 5 minutes).

[0078] As shown in Table 4, charging time data of an electric vehicle is provided, which includes the time consumed to charge the SOC to 80% according to the conventional thermal management control when the starting temperature of the battery cell is in different states.

[0079]

[0080] Table 4

[0081] As shown in Table 5, charging time data of an electric vehicle is provided, which includes the time consumed to charge the SOC to 80% according to the charging control method provided in the embodiments of the present application when the starting temperature of the battery cell is in different states.

[0082]

[0083] Table 5

[0084] Comparing the data in Table 4 and Table 5, it can be seen that regardless of the starting temperature of the battery cell, through the solution provided in the embodiments of the present application, since the temperature of the battery cell can be adjusted to the most suitable target temperature T_target before arriving at the charging pile; therefore, it is ensured that the charging time is the shortest.

[0085] Scenario 2: After the charging pile starts charging the battery cell, the battery cell can be heated (cooled) through thermal management while charging until the temperature of the battery cell is controlled to the target temperature in the target temperature rise curve.

[0086] It should be noted that when the temperature of the battery cell does not meet the target temperature in the target temperature rise curve, the battery cell is heated to the target temperature through thermal management while being charged. If the temperature of the battery cell meets the target temperature in the target temperature rise curve, no thermal management is performed on the battery cell. Refer to Figure 7 As shown, in step 401, when the electric vehicle arrives at the charging station, the charging gun is inserted to charge the battery cell through the charging pile, and the BMS communicates with the charging pile to obtain the maximum charging current Ipile of the charging pile. In step 402, according to the current SOC (which can be taken to the right) and the maximum charging current Ipile, the temperature T_pilecurrent of the battery cell that can fully utilize the capacity of the charging pile is obtained by looking up Table 1. At the same time, in step 403, according to the current SOC (which can be taken to the right), the temperature T_optimal corresponding to the target temperature rise curve (the first temperature rise curve) is obtained by looking up Table 2. Different from Scenario 1, in this Scenario 2, thermal management can be performed on the battery cell while charging until the temperature of the battery cell is equal to the target temperature T_target. Among them, considering the hysteresis of thermal management in adjusting the temperature of the battery cell, the specific method of looking up the table can be as follows: According to the current SOC, take a value to the right in the corresponding interval, and then take the adjacent SOC interval on the right to obtain the corresponding temperature of the battery cell. For example, when the SOC is 32%, the value taken to the right is 35%, and then the adjacent SOC interval on the right is 40%. Referring to Table 3, the temperature value of T_pilecurrent is 25°C. Referring to Table 2, the temperature value of T_optimal is 31°C.

[0087] After that, since the capabilities of the charging piles at different destinations are different, the relative magnitude relationship between T_optimal and T_pilecurrent can be divided into two major cases. In step 404, the BMS detects the current temperature T of the battery cell, determines the target temperature T_target according to the relationship between T, T_optimal, and T_pilecurrent, and then performs thermal management control on the battery cell to control the temperature of the battery cell to reach the target temperature T_target, specifically as follows:

[0088] 1) T_optimal < T_pilecurrent

[0089] ① T < T_optimal < T_pilecurrent: The temperature T of the battery cell is lower than T_optimal. To achieve a faster charging speed by further heating, the heating target temperature T_target = T_optimal is determined according to the first temperature rise curve.

[0090] ②When T_optimal < T < T_pilecurrent, or T_optimal < T_pilecurrent < T: The temperature T of the battery cell is higher than T_optimal. In the later stage of charging, it may exceed the current limiting temperature and affect the charging speed. Therefore, it is necessary to cool the battery cell, and the cooling target temperature T_target = T_optimal is determined according to the first temperature rise curve.

[0091] 2) T_pilecurrent < T_optimal

[0092] ①When T < T_pilecurrent < T_optimal: The temperature T of the battery cell is lower than T_pilecurrent, and T_pilecurrent is lower than T_optimal. Therefore, it is necessary to heat the battery cell to further make full use of the charging pile's capacity, and the heating target temperature T_target = T_pilecurrent is determined according to the second temperature rise curve.

[0093] ②When T_pilecurrent < T < T_optimal, or T_pilecurrent < T_optimal < T: The charging pile's capacity can already be fully utilized and is limited by the pile's capacity. There is no need to turn on the thermal management function and no processing is required.

[0094] Since the SOC will continuously increase during the charging process, and the temperature of the battery cell will also change under the thermal management measures, the state of charge of the battery cell can be detected periodically, and then the target temperature T_target can be refreshed periodically (such as every 5% SOC).

[0095] Referring to Table 6, charging time data of an electric vehicle are provided, which include the time consumed to charge the SOC from 30% to 80% with the starting temperature of the battery cell in different states under conventional thermal management (thermal management while charging to 20°C); and the time consumed to charge the SOC from 30% to 80% after the temperature of the battery cell is thermally managed to the target temperature in the embodiments of the present application.

[0096]

[0097] Table 6

[0098] Comparing the data in Table 6, it can be seen that regardless of the starting temperature of the battery cell, through the solution provided by the embodiments of the present application, since the temperature of the battery cell can be adjusted to the most suitable target temperature T_target while charging at the beginning of charging; therefore, it is ensured that the charging time is the shortest.

[0099] It is understandable that, in order to realize the above functions, the above-mentioned charging control device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and algorithm operations of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0100] The embodiment of the present application can divide the functional modules of the charging control device according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. There may be other division methods in actual implementation.

[0101] For example, when the functional modules are divided in an integrated manner, Figure 8 A schematic diagram of the structure of a charging control device is shown. The charging control device can be a mobile device itself or a chip or system on chip in the mobile device, or other combined devices, components, etc. that can realize the functions of the above-mentioned charging control device. The charging control device can be used to perform the functions of the charging control device involved in the above-mentioned embodiments.

[0102] As a possible implementation, Figure 8 The charging control device 80 shown includes: a detection module 801 and a processing module 802; the detection module 801 is used to execute step S101; the processing module 802 is used to execute step S102.

[0103] Among them, all relevant contents of each operation involved in the above method embodiment can be referred to the functional description of the corresponding functional module, and will not be repeated here.

[0104] In this embodiment, the electronic device can be presented in the form of various functional modules divided in an integrated manner. The "module" here can refer to a specific ASIC, circuit, processor and memory that executes one or more software or firmware programs, integrated logic circuit, and / or other devices that can provide the above functions. In a simple embodiment, a person skilled in the art can imagine that the charging control device can be used Figure 2 The form of the charging control device shown.

[0105] for example, Figure 2 The processor 201 in the electronic device can call the computer execution instructions stored in the internal memory 202 to enable the electronic device to execute the charging control method in the above method embodiment.

[0106] For example, Figure 8 The functions / implementation processes of the detection module 801 and the processing module 802 can be Figure 2 The processor 201 in the system calls the computer execution instructions stored in the internal memory 202 to implement the above.

[0107] Since the charging control device provided in this embodiment can execute the above-mentioned charging control method, the technical effects that can be obtained can refer to the above-mentioned method embodiment, which will not be repeated here.

[0108] Optionally, an embodiment of the present application further provides a charging control device (for example, the charging control device may be a chip or a chip system). When the charging control device is a chip system, it may be composed of chips, or may include chips and other discrete devices. The embodiment of the present application does not specifically limit this.

[0109] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using a software program, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or may contain one or more servers, data centers and other data storage devices that can be integrated with the medium. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state disk (SSD)), etc. In the embodiment of the present application, the computer may include the aforementioned device.

[0110] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in a claim. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0111] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A charging control method, applied to a mobile device, wherein the mobile device is used to connect to a charging pile to form a charging system, and the charging pile is used to charge the battery cell of the mobile device; characterized in that: The method includes: detecting the temperature of the battery cell; If the temperature of the battery cell is equal to the target temperature, the heating function of the battery cell is turned off until charging is completed. The temperature change of the battery cell is positively correlated with the internal resistance of the battery cell and the charging current provided by the charging pile.

2. The charging control method according to claim 1, characterized in that: If the temperature of the battery cell is not equal to the target temperature, the method further includes: A thermal management function for the battery cell is enabled, where the thermal management function includes a heating function or a cooling function.

3. The charging control method according to claim 1 or 2, characterized in that: After the heating function of the battery cell is turned off, the cooling of the battery cell is kept in a turned-off state during the charging process of the battery cell.

4. The charging control method according to claim 1 or 2, characterized in that: After the heating function of the battery cell is turned off, if the temperature of the battery cell is greater than or equal to a first temperature, the cooling function is turned on to cool the battery cell, and the first temperature is lower than a current limiting temperature.

5. The charging control method according to any one of claims 1 to 4, characterized in that: The method further comprises: Obtaining the state of charge of the battery cell; The target temperature is determined according to the state of charge and the target temperature rise curve; wherein the distance between the target temperature and the target temperature rise curve is less than or equal to a predetermined error value, the abscissa of the target temperature rise curve is the state of charge, and the ordinate of the target temperature rise curve is the temperature.

6. The charging control method according to any one of claims 1 to 4, characterized in that: After turning off the heating function of the battery cell, at any charge state, the distance between the temperature of the battery cell and the target temperature rise curve is less than or equal to a predetermined error value, the abscissa of the target temperature rise curve is the charge state, and the ordinate of the target temperature rise curve is the temperature.

7. The charging control method according to claim 5 or 6, characterized in that: The method further comprises: Get the ambient temperature; The target temperature rise curve is determined according to the ambient temperature; wherein, under the same state of charge, the temperature on the target temperature rise curve is negatively correlated with the ambient temperature.

8. The charging control method according to claim 5, characterized in that: The method further includes: determining the target temperature rise curve according to the maximum charging current of the charging pile.

9. The charging control method according to claim 8, characterized in that: The determining the target temperature rise curve according to the maximum charging current of the charging pile includes: In the state of charge, if the temperature of the battery cell corresponding to the maximum charging current of the charging pile is greater than the temperature on the first temperature rise curve, the first temperature rise curve is used as the target temperature rise curve; the abscissa of the first temperature rise curve is the state of charge, and the ordinate of the first temperature rise curve is the temperature; In the charged state, if the temperature of the battery cell corresponding to the maximum charging current of the charging pile is lower than the temperature on the first temperature rise curve, the second temperature rise curve is used as the target temperature rise curve, the abscissa of the second temperature rise curve is the charged state, and the ordinate of the second temperature rise curve is the temperature; in the charged state, the temperature on the second temperature rise curve is lower than the temperature on the first temperature rise curve.

10. The charging control method according to claim 5, characterized in that: The acquiring the state of charge of the battery cell specifically includes: acquiring navigation information, and determining the state of charge of the battery cell when navigating to the charging pile according to the navigation information.

11. The charging control method according to claim 5, characterized in that: The acquiring the state of charge of the battery cell specifically includes: acquiring the state of charge of the battery cell after the charging pile charges the battery cell of the mobile device.

12. A charging control device, applied to a mobile device, wherein the mobile device is used to connect to a charging pile to form a charging system, and the charging pile is used to charge the battery cell of the mobile device; characterized in that: include: a processor and a memory coupled to the processor; The memory stores program codes, and the processor is used to execute the program codes in the memory to execute the charging control method according to any one of claims 1 to 11.

13. A chip, characterized in that: Comprising the charging control device as claimed in claim 12.

14. A mobile device, characterized in that: The invention comprises a battery cell and a charging control device as claimed in claim 12 connected to the battery cell.

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