Dynamic heating control method, device, electronic device and storage medium for low-temperature charging of batteries

Abstract

The present application provides a dynamic heating control method, device, electronic device and storage medium for low-temperature charging of a battery, wherein the dynamic heating control method for low-temperature charging of a battery includes: dynamically adjusting the lower and upper limits of the battery heating threshold based on the current SOC of the battery; and dynamically adjusting the target water temperature based on the current total heat absorption of the battery. The present application can dynamically adjust the target water temperature used for heating so that the temperature rise rate of the battery dynamically corresponds to the current total heat absorption of the battery, thereby avoiding slow heating and longer charging time due to a too small temperature rise rate, and larger temperature difference and shorter service life due to an excessively large temperature rise rate. At the same time, by controlling the battery heating threshold to change in real time with the charging process, it is ensured that the battery can enter or exit heating in time according to the corresponding heating threshold at different charging stages, so that the battery is always maintained within the optimal charging temperature range, while taking into account both reducing charging time and reducing heating energy consumption.

Description

Technical Field

[0001] The present application relates to the field of battery heating, and more specifically, to a dynamic heating control method, device, electronic device, and storage medium for low-temperature charging of a battery. Background Art

[0002] As a core component of electric vehicles, the power battery pack must operate within the appropriate temperature range to ensure optimal charge and discharge performance, safety, and service life. When the battery is exposed to low temperatures, its discharge capacity, maximum discharge power, and charging power are significantly reduced, significantly impacting the vehicle's range, power, and charging efficiency. In particular, using high currents directly in low-temperature charging conditions can easily lead to lithium deposition, resulting in reduced service life, or even internal short circuits and thermal runaway, severely impacting service life and safety. Therefore, when charging batteries in low-temperature environments, it is generally necessary to heat the batteries to the appropriate temperature before charging. Currently, the mainstream battery heating method uses a PTC (Positive Temperature Coefficient) heater. This heater first heats the coolant in the battery circuit, which then flows through the battery cold plate and transfers heat to the battery, thereby heating the battery.

[0003] The current mainstream battery heating method mainly uses PTC heaters to heat the battery, and most of them use fixed heating target water temperature and battery heating threshold to control the heating process. However, this heating control method has the following disadvantages:

[0004] On the one hand, during the charging process, the battery's own heat generation and the heat exchange between the battery and the coolant change over time. If a fixed target heating water temperature is used for heating, the battery's temperature rise rate will vary greatly over time, making it impossible to control the temperature rise rate within an appropriate range. Too slow a temperature rise rate will result in slower heating and longer charging times, while too high a temperature rise rate will lead to larger battery temperature differences and shortened service life. Therefore, the target water temperature should be dynamically adjusted based on the changes in the battery's own heat generation and the heat exchange between the battery and the coolant.

[0005] On the other hand, since the charging rate gradually decreases as the battery SOC increases during the charging process, that is, the battery self-heat gradually decreases, so under low-temperature charging conditions, if a fixed battery heating threshold is used for heating, the following three situations will occur: (1) The battery starts charging from a low SOC, for example, the SOC is charged from 0% to 100%. In the process of charging the battery from a low SOC to a high SOC (for example, SOC from 0% to 80%), due to the large self-heat of the battery, the heating can be stopped by heating the battery to a lower heating threshold, and then the battery temperature can be raised to the temperature range of high-rate charging by relying on the battery self-heating. When the battery continues to charge to a high SOC (for example, SOC from 80% to 100%), the battery's self-heating may be greatly reduced, and the self-heating may be less than the external heat exchange, resulting in a phenomenon of continuous temperature reduction. In order to avoid the situation where the charging rate is reduced due to the reduction of battery temperature after high SOC, a higher heating threshold than that at low SOC should be used for timely intervention, so that heating can be started earlier after high SOC to prevent the battery temperature from continuing to decrease; (2) The battery starts to charge from a higher SOC, for example, the SOC is charged from 60% to 100%, in which when the battery is first charged from a higher SOC to a high SOC (for example, SOC From 60%-80%), since the battery charging rate at this time is lower than the charging rate at low SOC, the battery's self-heating is also lower than that at low SOC. If the battery is still heated to a lower heating threshold and then stopped heating, the battery cannot achieve temperature rise to the high-rate charging temperature range by relying on the lower self-heating. Therefore, in order to increase the charging rate, the battery should be heated to a higher heating threshold than the low SOC and then stop heating; and when the battery continues to charge to a high SOC (for example, SOC from 80%-100%), since the battery's self-heating will be further reduced, the self-heating may be less than the external heat exchange, resulting in temperature The phenomenon of continuous decrease. In order to avoid the situation where the charging rate decreases due to the decrease in battery temperature after high SOC, a higher heating threshold than that at low SOC and high SOC should be used for timely intervention, so that heating can be started earlier after high SOC to prevent the battery temperature from continuing to decrease; (3) When the battery starts charging from a high SOC, for example, the SOC is charged from 80% to 100%, since the battery charging rate is very small at this time, the battery self-heating is also very small, and the battery temperature rise caused by self-heating is very small. Only by heating the battery to a higher heating threshold and then stopping heating can the battery temperature be raised to a suitable range to further increase the charging rate. Therefore, if a fixed battery heating threshold is used for heating, it will not be able to adapt to the entire charging process, cannot meet the battery heating requirements of different charging stages, and cannot always maintain the battery within the optimal charging temperature range, resulting in an increase in charging time and heating energy consumption. Therefore, the battery heating threshold should be dynamically adjusted according to the different charging stages of the battery. Summary of the Invention

[0006] The purpose of the embodiments of the present application is to provide a dynamic heating control method, device, electronic device, and storage medium for low-temperature battery charging, which dynamically adjusts the target water temperature used for heating so that the battery's temperature rise rate corresponds dynamically to the battery's current total heat absorption, thereby avoiding slow heating and prolonged charging time caused by a too low temperature rise rate, and large temperature differences and shortened service life caused by an excessively large temperature rise rate. At the same time, by controlling the battery's heating threshold to change in real time with the charging process, it is ensured that the battery can enter or exit heating in a timely manner according to the corresponding heating threshold at different charging stages, so that the battery is always maintained within the optimal charging temperature range, while taking into account both reducing charging time and reducing heating energy consumption.

[0007] In a first aspect, the present invention provides a dynamic heating control method for low-temperature charging of a battery, the method comprising:

[0008] Obtaining a current SOC of a battery and calculating a current total heat absorption of the battery;

[0009] dynamically adjusting a lower limit of a battery heating threshold and an upper limit of a battery heating threshold based on a current SOC of the battery, wherein heating is enabled when the lowest temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and heating is disabled when the lowest temperature of the battery is greater than or equal to the upper limit of the battery heating threshold;

[0010] The target water temperature is dynamically adjusted based on the current total heat absorption of the battery, and the battery is heated at the target water temperature, wherein the target water temperature corresponds to the temperature rise rate of the battery.

[0011] The method of the first aspect of the present application obtains the current SOC of the battery and calculates the current total heat absorption of the battery, thereby dynamically adjusting the lower limit and upper limit of the battery heating threshold based on the current SOC of the battery. Heating is enabled when the minimum temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and is disabled when the minimum temperature of the battery is greater than or equal to the upper limit of the battery heating threshold. Furthermore, the target water temperature is dynamically adjusted based on the current total heat absorption of the battery, and the battery is heated at the target water temperature, wherein the target water temperature corresponds to the temperature rise rate of the battery. Compared with the prior art, by dynamically adjusting the target water temperature for heating, the temperature rise rate of the battery is dynamically aligned with the current total heat absorption of the battery, thereby avoiding slow heating and prolonged charging time due to an excessively low temperature rise rate, and large temperature differences and shortened service life due to an excessively high temperature rise rate. At the same time, by controlling the battery heating threshold to change in real time as the charging process progresses, the battery is ensured to enter or exit heating in a timely manner according to the corresponding heating threshold at different charging stages, so that the battery is always maintained within the optimal charging temperature range, while simultaneously reducing charging time and heating energy consumption.

[0012] In an optional embodiment, the dynamically adjusting the target water temperature based on the current total heat absorption of the battery includes:

[0013] When the current total heat absorption of the battery is less than or equal to a first heat absorption threshold, adjusting the target water temperature to a first temperature value;

[0014] When the current total heat absorption of the battery is less than or equal to a second heat absorption threshold, adjusting the target water temperature to a second temperature value, wherein the second heat absorption threshold is greater than the first heat absorption threshold, and the second temperature value is less than the first temperature value;

[0015] When the current total heat absorption of the battery is greater than the second heat absorption threshold, the target water temperature is adjusted to a third temperature value, which is lower than the second temperature value.

[0016] This optional implementation manner can adjust the target water temperature to a first temperature value when the current total heat absorption of the battery is less than or equal to a first heat absorption threshold, and adjust the target water temperature to a second temperature value when the current total heat absorption of the battery is less than or equal to a second heat absorption threshold, wherein the second heat absorption threshold is greater than the first heat absorption threshold, and the second temperature value is less than the first temperature value; on the other hand, it can adjust the target water temperature to a third temperature value when the current total heat absorption of the battery is greater than the second heat absorption threshold, and the third temperature value is less than the second temperature value.

[0017] In an optional embodiment, dynamically adjusting a lower limit of a battery heating threshold and an upper limit of a battery heating threshold based on a current SOC of the battery includes:

[0018] When the current SOC of the battery is less than or equal to a first SOC threshold, the lower limit of the battery heating threshold is a first value, and the upper limit of the battery heating threshold is a second value, wherein the second value is greater than the first value;

[0019] When the current SOC of the battery is less than or equal to a second SOC threshold, the lower limit of the battery heating threshold is a third value, and the upper limit of the battery heating threshold is a fourth value, wherein the fourth value is greater than the third value, and wherein the second SOC threshold is greater than the first SOC threshold;

[0020] When the current SOC of the battery is greater than the second SOC threshold, the lower limit of the battery heating threshold is a fifth value, and the upper limit of the battery heating threshold is a sixth value, wherein the sixth value is greater than the fifth value.

[0021] This optional implementation manner can, when the current SOC of the battery is less than or equal to the first SOC threshold, set the lower limit of the battery heating threshold to a first value, and set the upper limit of the battery heating threshold to a second value, wherein the second value is greater than the first value; and when the current SOC of the battery is less than or equal to the second SOC threshold, set the lower limit of the battery heating threshold to a third value, and set the upper limit of the battery heating threshold to a fourth value, wherein the fourth value is greater than the third value, and wherein the second SOC threshold is greater than the first SOC threshold; on the other hand, when the current SOC of the battery is greater than the second SOC threshold, set the lower limit of the battery heating threshold to a fifth value, and set the upper limit of the battery heating threshold to a sixth value, wherein the sixth value is greater than the fifth value.

[0022] In an optional embodiment, calculating the current total heat absorption of the battery includes:

[0023] Obtaining the current charging current of the battery, the current mass flow rate of the coolant, the specific heat capacity of the coolant, the inlet and outlet temperature difference, and the current internal resistance of the battery;

[0024] calculating a current self-heating amount of the battery based on a current internal resistance of the battery and a current charging current of the battery;

[0025] Calculating the heat exchange amount between the coolant and the battery based on the inlet and outlet temperature difference, the current mass flow rate of the coolant, and the specific heat capacity of the coolant;

[0026] The current total heat absorption of the battery is calculated based on the heat exchange between the coolant and the battery and the current self-heating of the battery.

[0027] This optional implementation method obtains the current charging current of the battery, the current mass flow rate of the coolant, the specific heat capacity of the coolant, the inlet and outlet temperature difference and the current internal resistance of the battery, and thus can calculate the current self-heating of the battery based on the current internal resistance of the battery and the current charging current of the battery, and can calculate the heat exchange between the coolant and the battery based on the inlet and outlet temperature difference, the current mass flow rate of the coolant and the specific heat capacity of the coolant, thereby calculating the current total heat absorption of the battery based on the heat exchange between the coolant and the battery and the current self-heating of the battery.

[0028] In an optional embodiment, the calculation formula for calculating the heat exchange between the coolant and the battery based on the inlet and outlet temperature difference, the current mass flow rate of the coolant, and the specific heat capacity of the coolant is:

[0029] Pf=Qm*Cp*ΔT;

[0030] Wherein, Pf represents the heat exchange between the coolant and the battery, Qm represents the current mass flow rate of the coolant, ΔT represents the inlet and outlet temperature difference, and Cp represents the specific heat capacity of the coolant.

[0031] This optional implementation can accurately calculate the heat exchange amount between the coolant and the battery through the above calculation formula.

[0032] In an optional embodiment, the method further comprises:

[0033] When the current SOC of the battery is greater than or equal to the charging cut-off SOC, charging of the battery is stopped.

[0034] This optional implementation manner can stop charging the battery when the current SOC of the battery is greater than or equal to the charging cut-off SOC.

[0035] In an optional embodiment, the method further comprises:

[0036] Obtaining the current minimum temperature of the battery;

[0037] When the current lowest temperature of the battery is greater than or equal to the upper limit of the battery heating threshold, heating is terminated and the heating state of the battery is updated.

[0038] This optional implementation manner obtains the current minimum temperature of the battery, and thus can exit heating and update the heating state of the battery when the current minimum temperature of the battery is greater than or equal to the upper limit of the battery heating threshold.

[0039] In a second aspect, the present invention provides a dynamic heating control device for low-temperature charging of a battery, the device comprising:

[0040] an acquisition module, configured to acquire a current SOC of a battery and calculate a current total heat absorption of the battery;

[0041] a first dynamic adjustment module, configured to dynamically adjust a lower limit of a battery heating threshold and an upper limit of a battery heating threshold based on a current SOC of the battery, wherein heating is enabled when a minimum temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and heating is disabled when the minimum temperature of the battery is greater than or equal to the upper limit of the battery heating threshold;

[0042] The second dynamic adjustment module is configured to dynamically adjust a target water temperature based on a current total heat absorption of the battery, and heat the battery at the target water temperature, wherein the target water temperature corresponds to a temperature rise rate of the battery.

[0043] The device of the second aspect of the present application obtains the current SOC of the battery and calculates the current total heat absorption of the battery, thereby dynamically adjusting the lower limit and upper limit of the battery heating threshold based on the current SOC of the battery. Heating is initiated when the minimum temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and is terminated when the minimum temperature of the battery is greater than or equal to the upper limit of the battery heating threshold. Furthermore, the device dynamically adjusts the target water temperature based on the current total heat absorption of the battery, heating the battery at the target water temperature, wherein the target water temperature corresponds to the temperature rise rate of the battery. Compared with the prior art, by dynamically adjusting the target water temperature for heating, the temperature rise rate of the battery is dynamically aligned with the current total heat absorption of the battery, thereby avoiding slow heating and prolonged charging time due to an excessively slow temperature rise rate, and large temperature differences and shortened service life due to an excessively large temperature rise rate. Furthermore, by controlling the battery heating threshold to change in real time as the charging process progresses, the battery is ensured to enter or exit heating in a timely manner according to the corresponding heating threshold at different charging stages, thereby maintaining the battery within the optimal charging temperature range, while simultaneously reducing charging time and heating energy consumption.

[0044] In a third aspect, the present invention provides an electronic device, comprising:

[0045] processor; and

[0046] A memory is configured to store machine-readable instructions, which, when executed by the processor, execute the dynamic heating control method for low-temperature charging of a battery as described in any of the aforementioned embodiments.

[0047] The electronic device of the third aspect of the present application, by executing a dynamic heating control method for low-temperature battery charging, can dynamically adjust the target water temperature used for heating, so that the battery's temperature rise rate dynamically corresponds to the battery's current total heat absorption, thereby avoiding slow heating and prolonged charging time caused by an excessively low temperature rise rate, and large temperature differences and shortened service life caused by an excessively high temperature rise rate. At the same time, by controlling the battery's heating threshold to change in real time with the charging process, it is ensured that the battery can enter or exit heating in a timely manner according to the corresponding heating threshold at different charging stages, so that the battery is always maintained within the optimal charging temperature range, while taking into account both reducing charging time and reducing heating energy consumption.

[0048] In a fourth aspect, the present invention provides a storage medium storing a computer program, wherein the computer program is executed by a processor to implement the dynamic heating control method for low-temperature charging of a battery as described in any one of the aforementioned embodiments.

[0049] The storage medium of the fourth aspect of the present application, by executing a dynamic heating control method for low-temperature battery charging, can dynamically adjust the target water temperature used for heating, so that the battery's temperature rise rate dynamically corresponds to the battery's current total heat absorption, thereby avoiding slow heating and prolonged charging time caused by an excessively low temperature rise rate, and large temperature differences and shortened service life caused by an excessively high temperature rise rate. At the same time, by controlling the battery's heating threshold to change in real time with the charging process, it is ensured that the battery can enter or exit heating in a timely manner according to the corresponding heating threshold at different charging stages, so that the battery is always maintained within the optimal charging temperature range, while taking into account both reducing charging time and reducing heating energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0051] Figure 1 This is a flow chart of a dynamic heating control method for low-temperature charging of a battery disclosed in an embodiment of the present application;

[0052] Figure 2 This is a schematic structural diagram of a dynamic heating control device for low-temperature charging of a battery disclosed in an embodiment of the present application;

[0053] Figure 3 This is a structural diagram of an electronic device disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0055] Example 1

[0056] See also Figure 1 , Figure 1 This is a flow chart of a dynamic heating control method for low-temperature charging of a battery disclosed in an embodiment of the present application, such as Figure 1 As shown, the method of the embodiment of the present application includes the following steps:

[0057] 101. Obtain the current SOC of the battery and calculate the current total heat absorption of the battery;

[0058] 102. Dynamically adjust the lower limit and upper limit of the battery heating threshold based on the current SOC of the battery, wherein heating is turned on when the lowest battery temperature is less than or equal to the lower limit of the battery heating threshold, and heating is turned off when the lowest battery temperature is greater than or equal to the upper limit of the battery heating threshold;

[0059] 103. Dynamically adjust the target water temperature based on the current total heat absorption of the battery, and heat the battery at the target water temperature, wherein the target water temperature corresponds to the temperature rise rate of the battery.

[0060] The method of the embodiment of the present application obtains the current SOC of the battery and calculates the current total heat absorption of the battery, and then dynamically adjusts the lower limit of the battery heating threshold and the upper limit of the battery heating threshold based on the current SOC of the battery. When the minimum temperature of the battery is less than or equal to the lower limit of the battery heating threshold, heating is turned on, and when the minimum temperature of the battery is greater than or equal to the upper limit of the battery heating threshold, heating is stopped. Then, the target water temperature can be dynamically adjusted based on the current total heat absorption of the battery, and the battery is heated at the target water temperature, wherein the target water temperature corresponds to the temperature rise rate of the battery. Compared with the prior art, by dynamically adjusting the target water temperature for heating, the temperature rise rate of the battery is dynamically aligned with the current total heat absorption of the battery, thereby avoiding slow heating and prolonged charging time caused by too low a temperature rise rate, and large temperature difference and shortened service life caused by too high a temperature rise rate. At the same time, by controlling the battery heating threshold to change in real time with the charging process, it is ensured that the battery can enter or exit heating in a timely manner according to the corresponding heating threshold at different charging stages, so that the battery is always maintained within the optimal charging temperature range, taking into account both reducing charging time and reducing heating energy consumption.

[0061] In an embodiment of the present application, step 101 may be executed after the vehicle starts charging, wherein when the charging gun is successfully connected to the vehicle, the battery begins to enter the charging process.

[0062] In the embodiment of the present application, the current SOC of the battery refers to the SOC of the battery at the current moment, wherein SOC (State of Charge) refers to the ratio of the current remaining capacity of the battery to its total capacity in a fully charged state, usually expressed as a percentage.

[0063] In the embodiment of the present application, the current total heat absorption of the battery refers to the total heat absorption of the battery at the current moment, wherein the total heat absorption includes the heat generated by the battery itself and the heat exchange between the battery and the coolant.

[0064] In an embodiment of the present application, the target water temperature refers to the coolant temperature required to heat the battery. For example, when the coolant temperature of the heating battery is 50 degrees Celsius, a water temperature of 50 degrees Celsius is required to continuously heat the battery, and the target water temperature is 50 degrees Celsius.

[0065] In this embodiment of the present application, the target water temperature has an initial value. When it is detected that the battery has started charging, the target water temperature Tf and the heating state N are initialized, with the initial value of the target water temperature Tf set to Tf=Tf0 and the initial value of the heating state N set to N=0. Furthermore, steps 101-103 are a dynamic process. If this is the first time heating is turned on after the battery starts charging, heating is first turned on at the set initial value of the target water temperature Tf=Tf0. The target water temperature Tf is then dynamically adjusted according to steps 101-103, and heating is continued at the adjusted target water temperature. After determining that heating is necessary, the value of the heating state N is set to N=1. If this is not the first time heating is turned on during charging, heating is first turned on again at the target water temperature Tf that was used when heating was last exited. The target water temperature Tf is then dynamically adjusted according to steps 101-103, and heating is continued at the adjusted target water temperature. After determining that heating is necessary, the value of the heating state N is set to N=1.

[0066] In the embodiment of the present application, as an optional implementation, step: dynamically adjusting the target water temperature based on the current total heat absorption of the battery includes the following sub-steps:

[0067] When the current total heat absorption of the battery is less than or equal to the first heat absorption threshold, adjusting the target water temperature to the first temperature value;

[0068] When the current total heat absorption of the battery is less than or equal to a second heat absorption threshold, adjusting the target water temperature to a second temperature value, wherein the second heat absorption threshold is greater than the first heat absorption threshold, and the second temperature value is less than the first temperature value;

[0069] When the current total heat absorption of the battery is greater than the second heat absorption threshold, the target water temperature is adjusted to a third temperature value, which is lower than the second temperature value.

[0070] This optional implementation manner can adjust the target water temperature to a first temperature value when the current total heat absorption of the battery is less than or equal to a first heat absorption threshold, and adjust the target water temperature to a second temperature value when the current total heat absorption of the battery is less than or equal to a second heat absorption threshold, wherein the second heat absorption threshold is greater than the first heat absorption threshold, and the second temperature value is less than the first temperature value; on the other hand, it can adjust the target water temperature to a third temperature value when the current total heat absorption of the battery is greater than the second heat absorption threshold, and the third temperature value is less than the second temperature value.

[0071] In the above optional embodiment, if the current total battery heat absorption Pall is less than or equal to the first heat absorption threshold P1, the target water temperature Tf is adjusted to Tf1, and heating continues at the new target water temperature Tf1; if the current total battery heat absorption Pall is greater than the first heat absorption threshold P1 and less than or equal to the second heat absorption threshold P2, the target water temperature Tf is adjusted to Tf2, and heating continues at the new target water temperature Tf2; if the current total battery heat absorption Pall is greater than the second heat absorption threshold P2, the target water temperature Tf is adjusted to Tf3, and heating continues at the new target water temperature Tf3. In this case, the first heat absorption threshold P1 is less than the second heat absorption threshold P2, the target water temperature Tf1 is greater than the target water temperature Tf2, and the target water temperature Tf2 is greater than the target water temperature Tf3.

[0072] Furthermore, the target water temperature is adjusted according to the total heat absorption of the battery. The greater the current total heat absorption of the battery, the lower the target water temperature is set, and the smaller the current total heat absorption of the battery, the higher the target water temperature is set. The purpose is to balance the total heat absorption of the battery by dynamically adjusting the target water temperature, so that the total heat absorption of the battery is always stable within an appropriate range, thereby ensuring that the battery temperature rise rate is also controlled within an appropriate range.

[0073] Furthermore, based on the current battery inlet water temperature and the target water temperature Tf, PID feedback control is used to gradually heat the inlet water temperature to the target water temperature and maintain it near the target temperature until heating is terminated or the target water temperature jumps to the next target temperature. In actual control, the difference between the current battery inlet water temperature and the target water temperature is used as the input of the PID feedback controller, and the PTC heating power is used as the output. The PTC heating power is automatically adjusted to heat the inlet water temperature to the target water temperature and maintain it near the target water temperature.

[0074] Compared with the existing scheme, the temperature rise rate is mainly determined by directly monitoring the battery temperature rise within a certain time interval (i.e., temperature rise rate = temperature rise / time interval), and then the target water temperature is adjusted according to the size of the battery temperature rise rate, and then the battery temperature rise rate is controlled in turn. However, on the one hand, due to the existence of the thermal capacity of the battery and the coolant, this method has a certain lag in controlling the battery temperature rise rate. On the other hand, this feedback control method itself is lagging. The above two aspects lead to the control effect of this control method being untimely, which may cause the battery temperature rise rate to exceed the appropriate range, making it difficult to accurately control the battery temperature rise rate. This patent uses a method of adjusting the target water temperature according to the current total heat absorption of the battery to control the battery temperature rise rate. The advantage is that the battery temperature rise rate can be predicted in advance according to the current total heat absorption of the battery (temperature rise rate = total heat absorption of the battery / (battery mass * battery specific heat capacity)), and the battery temperature rise rate can be controlled by adjusting the target water temperature in advance before the battery has time to heat up according to the current total heat absorption of the battery. The control method has certain predictability and advancement, so that the battery temperature rise rate can be accurately controlled within an appropriate range, preventing the battery temperature rise rate from being too slow due to slow heating and long charging time, or too large due to large temperature rise rate. Increased temperature difference and shortened service life of the battery.

[0075] For the above optional implementation, the first heat absorption threshold P1 is 5000W, the second heat absorption threshold P2 is 8000W; the target water temperature Tf1 is 45°C, the target water temperature Tf2 is 40°C, and the target water temperature Tf3 is 35°C.

[0076] In the embodiment of the present application, as an optional implementation, step: dynamically adjusting the lower limit of the battery heating threshold and the upper limit of the battery heating threshold based on the current SOC of the battery includes the following sub-steps:

[0077] When the current SOC of the battery is less than or equal to a first SOC threshold, the lower limit of the battery heating threshold is a first value, and the upper limit of the battery heating threshold is a second value, wherein the second value is greater than the first value;

[0078] When the current SOC of the battery is less than or equal to the second SOC threshold, the lower limit of the battery heating threshold is a third value, and the upper limit of the battery heating threshold is a fourth value, wherein the fourth value is greater than the third value, and wherein the second SOC threshold is greater than the first SOC threshold;

[0079] When the current SOC of the battery is greater than the second SOC threshold, the lower limit of the battery heating threshold is a fifth value, and the upper limit of the battery heating threshold is a sixth value, wherein the sixth value is greater than the fifth value.

[0080] This optional implementation manner can, when the current SOC of the battery is less than or equal to the first SOC threshold, set the lower limit of the battery heating threshold to a first value, and set the upper limit of the battery heating threshold to a second value, wherein the second value is greater than the first value; and when the current SOC of the battery is less than or equal to the second SOC threshold, can set the lower limit of the battery heating threshold to a third value, and set the upper limit of the battery heating threshold to a fourth value, wherein the fourth value is greater than the third value, wherein the second SOC threshold is greater than the first SOC threshold; on the other hand, can set the lower limit of the battery heating threshold to a fifth value, and set the upper limit of the battery heating threshold to a sixth value, wherein the sixth value is greater than the fifth value, when the current SOC of the battery is greater than the second SOC threshold.

[0081] For the above optional embodiment, as an example, the first SOC threshold and the second SOC threshold are represented by H1 and H2 respectively, and the first, second, third, fourth, fifth and sixth values ​​are represented by T1, T2, T3, T4, T5 and T6 respectively. If the current SOC is less than or equal to the first SOC threshold H1, the battery heating threshold lower limit Tlow is set to T1, and the heating threshold upper limit Thigh is set to T2. If the current SOC is greater than the first SOC threshold H1 and less than or equal to the second SOC threshold H2, the battery heating threshold lower limit Tlow is set to T3, and the heating threshold upper limit Thigh is set to T4. If the current SOC is greater than the second SOC threshold H2, the battery heating threshold lower limit Tlow is set to T5, and the heating threshold upper limit Thigh is set to T6. The battery heating threshold lower limit is the minimum temperature for activating battery heating. When the minimum battery temperature is less than or equal to the battery heating threshold lower limit, battery heating is activated. The battery heating threshold upper limit is the maximum temperature for terminating battery heating. When the minimum battery temperature is greater than or equal to the battery heating threshold upper limit, battery heating is deactivated. Among them, the first SOC threshold H1 is less than the second SOC threshold H2; the heating threshold lower limit T1 is less than the heating threshold upper limit T2, the heating threshold lower limit T3 is less than the heating threshold upper limit T4, and the heating threshold lower limit T5 is less than the heating threshold upper limit T6; the heating threshold lower limit T1 is less than the heating threshold lower limit T3, and the heating threshold lower limit T3 is less than the heating threshold lower limit T5; the heating threshold upper limit T2 is less than the heating threshold upper limit T4, and the heating threshold upper limit T4 is less than the heating threshold upper limit T6.

[0082] In the above optional implementation, each pair of heating thresholds includes a lower limit and an upper limit. The purpose is to avoid the phenomenon of frequent start and stop of heating that may occur when only one heating threshold is set, enhance the anti-interference ability of heating control, and avoid excess energy consumption caused by frequent start and stop of heating.

[0083] In the above optional implementation, as the SOC increases, the battery heating threshold is also set to a larger value. The reason is that during the charging process, as the battery power SOC increases, the charging rate gradually decreases, that is, the battery self-heat gradually decreases. Therefore, under low-temperature charging conditions, in order to always maintain the battery within the optimal charging temperature range while reducing the charging time and heating energy consumption, the battery heating threshold must be dynamically adjusted according to the current charging SOC range of the battery to adapt to the entire charging process and meet the battery heating requirements at different charging stages.

[0084] In the above optional embodiment, the above heating control method of dynamically adjusting the heating threshold can better cope with the following three typical low-temperature charging scenarios: (1) The battery starts charging from a low SOC, for example, the SOC is charged from 0% to 100%. When the battery is first charged from a low SOC to a high SOC (for example, the SOC is from 0% to 80%), due to the large amount of self-heating of the battery, the heating can be stopped by heating the battery to a lower heating threshold. Then, the battery temperature can be raised to the temperature range of high-rate charging by relying on the self-heating of the battery. When the battery continues to charge to a high SOC (for example, the SOC is from 80% to 100%), the battery temperature can be raised to the temperature range of high-rate charging by relying on the self-heating of the battery. 0%), since the battery self-heat is greatly reduced, the self-heat may be less than the external heat exchange, resulting in a phenomenon of continuous temperature reduction. In order to avoid the situation where the charging rate is reduced due to the reduction of battery temperature after high SOC, a higher heating threshold than that at low SOC should be used for timely intervention, so that heating can be started earlier after high SOC to prevent the battery temperature from continuing to decrease; (2) The battery starts to charge from a higher SOC, for example, the SOC is charged from 60% to 100%. In the process of charging the battery from a higher SOC to a high SOC (for example, the SOC is from 60% to 80%), since the battery is charged at this time The charging rate should be lower than the charging rate at low SOC, which results in the battery's self-heating being lower than that at low SOC. If the battery is still heated to a lower heating threshold and then stopped, the battery cannot achieve a temperature rise to the high-rate charging temperature range by relying on its lower self-heating. Therefore, in order to increase the charging rate, the battery should be heated to a higher heating threshold than that at low SOC before stopping heating. When the battery continues to charge to a high SOC (for example, SOC from 80% to 100%), the battery's self-heating will further decrease, and the self-heating may be less than the external heat exchange, resulting in a phenomenon of continuous temperature reduction. To avoid the situation where the charge rate is reduced due to the decrease in battery temperature after high SOC, a higher heating threshold than that at low SOC and high SOC should be used for timely intervention, so that heating can be started earlier after high SOC to prevent the battery temperature from continuing to decrease; (3) When the battery starts charging from a high SOC, for example, the SOC is charged from 80% to 100%, since the battery charge rate is very small at this time, the battery self-heating is also very small, and the battery temperature rise caused by self-heating is very small. The battery temperature can only be raised to a suitable range by heating the battery to a higher heating threshold and then stopping heating to further increase the charge rate.

[0085] In the embodiment of the present application, as an optional implementation, the step of calculating the current total heat absorption of the battery includes the following steps:

[0086] Obtain the current charging current of the battery, the current mass flow rate of the coolant, the specific heat capacity of the coolant, the inlet and outlet temperature difference, and the current internal resistance of the battery;

[0087] Calculate the current self-heating of the battery based on the current internal resistance of the battery and the current charging current of the battery;

[0088] Calculate the heat exchange between the coolant and the battery based on the inlet and outlet temperature difference, the current mass flow rate of the coolant, and the specific heat capacity of the coolant;

[0089] The current total heat absorption of the battery is calculated based on the heat exchange between the coolant and the battery and the current self-heating of the battery.

[0090] This optional implementation method obtains the current charging current of the battery, the current mass flow rate of the coolant, the specific heat capacity of the coolant, the inlet and outlet temperature difference and the current internal resistance of the battery, and can thereby calculate the current self-heating of the battery based on the current internal resistance of the battery and the current charging current of the battery, and can calculate the heat exchange between the coolant and the battery based on the inlet and outlet temperature difference, the current mass flow rate of the coolant and the specific heat capacity of the coolant, thereby calculating the current total heat absorption of the battery based on the heat exchange between the coolant and the battery and the current self-heating of the battery.

[0091] For the above optional implementation, the calculation formula corresponding to the current self-heating of the battery is:

[0092] Pcell=I 2 *R;

[0093] Among them, Pcell represents the current self-heating of the battery, R represents the current internal resistance of the battery, and I represents the current charging current of the battery.

[0094] For the above optional implementation, based on the heat exchange between the coolant and the battery and the current self-heating of the battery, the calculation formula for calculating the current total heat absorption of the battery is:

[0095] Pall=Pcell+Pf.

[0096] In the embodiment of the present application, as an optional implementation, the heat exchange amount between the coolant and the battery is calculated based on the inlet and outlet temperature difference, the current mass flow rate of the coolant, and the specific heat capacity of the coolant as follows:

[0097] Pf=Qm*Cp*ΔT;

[0098] Among them, Pf represents the heat exchange between the coolant and the battery, Qm represents the current mass flow rate of the coolant, ΔT represents the inlet and outlet temperature difference, and Cp represents the specific heat capacity of the coolant.

[0099] This optional implementation can accurately calculate the heat exchange amount between the coolant and the battery through the above calculation formula.

[0100] In the embodiment of the present application, as an optional implementation manner, the method of the embodiment of the present application further includes the following steps:

[0101] When the current SOC of the battery is greater than or equal to the charging cut-off SOC, charging of the battery is stopped.

[0102] This optional implementation can stop charging the battery when the current SOC of the battery is greater than or equal to the charging cut-off SOC.

[0103] In the embodiment of the present application, as an optional implementation manner, the method of the embodiment of the present application further includes the following steps:

[0104] Get the current minimum temperature of the battery;

[0105] When the current lowest temperature of the battery is greater than or equal to the upper limit of the battery heating threshold, heating is exited and the battery heating state is updated.

[0106] For the above optional implementation manner, the heating state of the battery is represented by N, wherein whether to turn on the heating is determined by judging whether the current heating state N is equal to 1. If N=1, the heating continues; otherwise, the heating is not turned on. This prevents the situation in which, when the battery is already in the heating-on state, the battery minimum temperature is heated from less than or equal to the lower limit of the battery heating threshold to between the lower limit of the battery heating threshold and the upper limit of the battery heating threshold, causing a misjudgment leading to premature exit of the heating. This ensures that the heating is normally exited only after the battery minimum temperature is heated to greater than or equal to the upper limit of the battery heating threshold.

[0107] Furthermore, when the heating state N≠1, it indicates that the current battery temperature does not meet the conditions for turning on heating, heating is not turned on, and it is determined whether to continue to execute the next heating control cycle or end charging.

[0108] This optional implementation manner obtains the current minimum temperature of the battery, and can exit heating and update the heating state of the battery when the current minimum temperature of the battery is greater than or equal to the upper limit of the battery heating threshold.

[0109] Example 2

[0110] See also Figure 2 , Figure 2 This is a schematic diagram of the structure of a dynamic heating control device for low-temperature charging of a battery disclosed in an embodiment of the present application. Figure 2 As shown, the device of the embodiment of the present application includes the following functional modules:

[0111] An acquisition module 201 is used to obtain the current SOC of the battery and calculate the current total heat absorption of the battery;

[0112] a first dynamic adjustment module 202, configured to dynamically adjust a lower limit of a battery heating threshold and an upper limit of a battery heating threshold based on a current SOC of the battery, wherein heating is enabled when the lowest battery temperature is less than or equal to the lower limit of the battery heating threshold, and is disabled when the lowest battery temperature is greater than or equal to the upper limit of the battery heating threshold;

[0113] The second dynamic adjustment module 203 is configured to dynamically adjust the target water temperature based on the current total heat absorption of the battery, so as to heat the battery at the target water temperature, wherein the target water temperature corresponds to the temperature rise rate of the battery.

[0114] The device of the embodiment of the present application obtains the current SOC of the battery and calculates the current total heat absorption of the battery, and then dynamically adjusts the lower limit and upper limit of the battery heating threshold based on the current SOC of the battery. When the minimum temperature of the battery is less than or equal to the lower limit of the battery heating threshold, heating is turned on, and when the minimum temperature of the battery is greater than or equal to the upper limit of the battery heating threshold, heating is stopped. Then, the target water temperature is dynamically adjusted based on the current total heat absorption of the battery, and the battery is heated at the target water temperature, wherein the target water temperature corresponds to the temperature rise rate of the battery. Compared with the prior art, by dynamically adjusting the target water temperature for heating, the temperature rise rate of the battery is dynamically aligned with the current total heat absorption of the battery, thereby avoiding slow heating and prolonged charging time caused by too low a temperature rise rate, and large temperature difference and shortened service life caused by too high a temperature rise rate. At the same time, by controlling the battery heating threshold to change in real time with the charging process, it is ensured that the battery can enter or exit heating in a timely manner according to the corresponding heating threshold at different charging stages, so that the battery is always maintained within the optimal charging temperature range, taking into account both reducing charging time and reducing heating energy consumption.

[0115] Example 3

[0116] See also Figure 3 , Figure 3 is a structural diagram of an electronic device disclosed in an embodiment of the present application, such as Figure 3 As shown, the electronic device of the embodiment of the present application includes:

[0117] Processor 301; and

[0118] The memory 302 is configured to store machine-readable instructions. When the instructions are executed by the processor 301, the dynamic heating control method for low-temperature charging of a battery as described in any of the aforementioned embodiments is executed.

[0119] The electronic device of the present application embodiment, by implementing a dynamic heating control method for low-temperature battery charging, can dynamically adjust the target water temperature used for heating, so that the battery's temperature rise rate dynamically corresponds to the battery's current total heat absorption, avoiding slow heating and prolonged charging time due to a too low temperature rise rate, and large temperature differences and shortened service life due to an excessively large temperature rise rate. At the same time, by controlling the battery's heating threshold to change in real time with the charging process, it is ensured that the battery can enter or exit heating in a timely manner according to the corresponding heating threshold at different charging stages, so that the battery is always maintained within the optimal charging temperature range, taking into account both shortening charging time and reducing heating energy consumption.

[0120] Example 4

[0121] An embodiment of the present application provides a storage medium storing a computer program, and the computer program is executed by a processor as in any one of the aforementioned embodiments for the dynamic heating control method for low-temperature charging of a battery.

[0122] The storage medium of the embodiment of the present application can dynamically adjust the target water temperature for heating by executing a dynamic heating control method for low-temperature battery charging, so that the battery's temperature rise rate dynamically corresponds to the battery's current total heat absorption, avoiding slow heating and prolonged charging time caused by a too small temperature rise rate, and large temperature differences and shortened service life caused by an excessively large temperature rise rate. At the same time, by controlling the battery's heating threshold to change in real time with the charging process, it is ensured that the battery can enter or exit heating in a timely manner according to the corresponding heating threshold at different charging stages, so that the battery is always maintained within the optimal charging temperature range, taking into account both reducing charging time and reducing heating energy consumption.

[0123] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interface, the indirect coupling or communication connection of the device or unit can be electrical, mechanical or other forms.

[0124] In addition, the units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0125] Furthermore, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0126] It should be noted that if the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0127] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any actual relationship or order between these entities or operations.

[0128] The above are merely examples of the present application and are not intended to limit the scope of protection of the present application. Those skilled in the art will appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A dynamic heating control method for low-temperature charging of a battery, characterized in that: The method comprises: Obtaining a current SOC of a battery and calculating a current total heat absorption of the battery; dynamically adjusting a lower limit of a battery heating threshold and an upper limit of a battery heating threshold based on a current SOC of the battery, wherein heating is enabled when the lowest temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and heating is disabled when the lowest temperature of the battery is greater than or equal to the upper limit of the battery heating threshold; dynamically adjusting a target water temperature based on a current total heat absorption of the battery, and heating the battery at the target water temperature, wherein the target water temperature corresponds to a temperature rise rate of the battery; Furthermore, calculating the current total heat absorption of the battery includes: Obtaining the current charging current of the battery, the current mass flow rate of the coolant, the specific heat capacity of the coolant, the inlet and outlet temperature difference, and the current internal resistance of the battery; calculating a current self-heating amount of the battery based on a current internal resistance of the battery and a current charging current of the battery; Calculating the heat exchange amount between the coolant and the battery based on the inlet and outlet temperature difference, the current mass flow rate of the coolant, and the specific heat capacity of the coolant; calculating a current total heat absorption of the battery based on a heat exchange amount between the coolant and the battery and a current self-heating amount of the battery; Furthermore, the calculation formula for calculating the heat exchange between the coolant and the battery based on the inlet and outlet temperature difference, the current mass flow rate of the coolant, and the specific heat capacity of the coolant is: Pf=Qm*Cp*ΔT; Wherein, Pf represents the heat exchange between the coolant and the battery, Qm represents the current mass flow rate of the coolant, ΔT represents the inlet and outlet temperature difference, and Cp represents the specific heat capacity of the coolant.

2. The method according to claim 1, wherein The dynamically adjusting the target water temperature based on the current total heat absorption of the battery includes: When the current total heat absorption of the battery is less than or equal to a first heat absorption threshold, adjusting the target water temperature to a first temperature value; When the current total heat absorption of the battery is less than or equal to a second heat absorption threshold, adjusting the target water temperature to a second temperature value, wherein the second heat absorption threshold is greater than the first heat absorption threshold, and the second temperature value is less than the first temperature value; When the current total heat absorption of the battery is greater than the second heat absorption threshold, the target water temperature is adjusted to a third temperature value, which is lower than the second temperature value.

3. The method according to claim 1, wherein The dynamically adjusting a lower limit of a battery heating threshold and an upper limit of a battery heating threshold based on a current SOC of the battery includes: When the current SOC of the battery is less than or equal to a first SOC threshold, the lower limit of the battery heating threshold is a first value, and the upper limit of the battery heating threshold is a second value, wherein the second value is greater than the first value; When the current SOC of the battery is less than or equal to a second SOC threshold, the lower limit of the battery heating threshold is a third value, and the upper limit of the battery heating threshold is a fourth value, wherein the fourth value is greater than the third value, and wherein the second SOC threshold is greater than the first SOC threshold; When the current SOC of the battery is greater than the second SOC threshold, the lower limit of the battery heating threshold is a fifth value, and the upper limit of the battery heating threshold is a sixth value, wherein the sixth value is greater than the fifth value.

4. The method according to claim 1, wherein The method further comprises: When the current SOC of the battery is greater than or equal to the charging cut-off SOC, charging of the battery is stopped.

5. The method according to claim 1, wherein The method further comprises: Obtaining the current minimum temperature of the battery; When the current lowest temperature of the battery is greater than or equal to the upper limit of the battery heating threshold, heating is terminated and the heating state of the battery is updated.

6. A dynamic heating control device for low-temperature charging of a battery, characterized in that: The device comprises: an acquisition module, configured to acquire a current SOC of a battery and calculate a current total heat absorption of the battery; a first dynamic adjustment module, configured to dynamically adjust a lower limit of a battery heating threshold and an upper limit of a battery heating threshold based on a current SOC of the battery, wherein heating is enabled when a minimum temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and heating is disabled when the minimum temperature of the battery is greater than or equal to the upper limit of the battery heating threshold; a second dynamic adjustment module, configured to dynamically adjust a target water temperature based on a current total heat absorption of the battery, and heat the battery at the target water temperature, wherein the target water temperature corresponds to a temperature rise rate of the battery; Furthermore, calculating the current total heat absorption of the battery includes: Obtaining the current charging current of the battery, the current mass flow rate of the coolant, the specific heat capacity of the coolant, the inlet and outlet temperature difference, and the current internal resistance of the battery; calculating a current self-heating amount of the battery based on a current internal resistance of the battery and a current charging current of the battery; Calculating the heat exchange amount between the coolant and the battery based on the inlet and outlet temperature difference, the current mass flow rate of the coolant, and the specific heat capacity of the coolant; calculating a current total heat absorption of the battery based on a heat exchange amount between the coolant and the battery and a current self-heating amount of the battery; Furthermore, the calculation formula for calculating the heat exchange between the coolant and the battery based on the inlet and outlet temperature difference, the current mass flow rate of the coolant, and the specific heat capacity of the coolant is: Pf=Qm*Cp*ΔT; Wherein, Pf represents the heat exchange between the coolant and the battery, Qm represents the current mass flow rate of the coolant, ΔT represents the inlet and outlet temperature difference, and Cp represents the specific heat capacity of the coolant.

7. An electronic device, characterized in that: include: processor; as well as A memory configured to store machine-readable instructions, which, when executed by the processor, execute the dynamic heating control method for low-temperature charging of a battery as described in any one of claims 1 to 5.

8. A storage medium, characterized in that: The storage medium stores a computer program, and the computer program is executed by a processor to implement the dynamic heating control method for low-temperature charging of a battery according to any one of claims 1 to 5.

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