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

Abstract

The invention provides a dynamic heating control method and device for low-temperature charging of a battery, electronic equipment and a storage medium, and the method comprises the steps: dynamically adjusting the lower limit and upper limit of a battery heating threshold value based on the current SOC of the battery; and dynamically adjusting the target water temperature based on the current total heat absorption amount of the battery. The target water temperature for heating can be dynamically adjusted, so that the temperature rise rate of the battery dynamically corresponds to the current total heat absorption capacity of the battery, and the situations that heating becomes slow and charging time becomes long due to the too small temperature rise rate and the temperature difference becomes large and the service life becomes short due to the too large temperature rise rate are avoided. And meanwhile, the heating threshold value of the battery is controlled to change in real time along with the charging process, so that the battery can enter or exit heating in time according to the corresponding heating threshold value in different charging stages, the battery is always maintained in the optimal charging temperature range, and both the charging time and the heating energy consumption are reduced.

Description

Technical Field

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

[0002] As the core component of electric vehicles, the power battery pack can only guarantee its charging and discharging performance, safety and service life if it works within the appropriate temperature range. When the battery is in a low temperature state, its dischargeable capacity, maximum discharge power and charging power are greatly reduced, which greatly affects the vehicle's cruising range, power and charging efficiency. Especially under low-temperature charging conditions, if a large current is used directly for charging, it is easy to cause lithium deposition and lead to life decay, and even cause internal short circuit and thermal runaway, which seriously affects the service life and safety. Therefore, when charging the battery in a low-temperature environment, it is generally necessary to heat the battery to a suitable temperature before charging it. At present, the mainstream battery heating method is mainly to heat the battery through a PTC (Positive Temperature Coefficient) heater. The PTC heater first heats the coolant in the battery circuit, and the coolant then flows through the battery cold plate and completes the heat transfer to the battery, thereby heating the battery.

[0003] The current mainstream battery heating method mainly uses a PTC heater to heat the battery, and most of them use a 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 heat generated by the battery itself and the heat exchange between the battery and the coolant change over time. If a fixed heating target water temperature is used for heating, the temperature rise rate of the battery will change greatly over time, and the temperature rise rate cannot be controlled within an appropriate range. If the temperature rise rate is too small, the heating will be slow and the charging time will be longer. If the temperature rise rate is too large, the battery temperature difference will become larger and the service life will be shortened. Therefore, the target water temperature should be dynamically adjusted according to the changes in the heat generated by the battery itself and the heat exchange between the battery and the coolant;

[0005] On the other hand, during the charging process, as the battery SOC increases, the charging rate gradually decreases, that is, the battery self-heat gradually decreases. Therefore, 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%. When the battery is charged from a low SOC to a high SOC (for example, the SOC is 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. 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 (e.g., SOC from 80% to 100%), the battery's self-heat is greatly reduced, and 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 in 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, such as SOC from 60% to 100%. In the process of charging the battery from a higher SOC to a high SOC (e.g., 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-heat is also 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 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%), the battery's self-heat will be further reduced, and the self-heat may be less than the external heat exchange, resulting in temperature 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 to charge 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. 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 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, meet the battery heating requirements at 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 charging of a battery, which is used to dynamically adjust the target water temperature for heating so that the temperature rise rate of the battery corresponds dynamically to the current total heat absorption of the battery, thereby avoiding slow heating and longer charging time due to too small a temperature rise rate, and large temperature difference and shorter service life due to too large a temperature rise rate. At the same time, by controlling the heating threshold of the battery 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 reducing the charging time and 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 turned on when a minimum temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and heating is stopped when a minimum 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, 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, wherein the heating is turned on when the lowest temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and the heating is exited when the lowest temperature of the battery is greater than or equal to the upper limit of the battery heating threshold, and 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 corresponding to the current total heat absorption of the battery, avoiding slow heating and long charging time caused by too small temperature rise rate, and large temperature difference and short service life caused by too large temperature rise rate. At the same time, by controlling the heating threshold of the battery 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, taking into account both reducing charging time and reducing heating energy consumption.

[0012] In an optional implementation, 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 less 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, when the current total heat absorption of the battery is greater than the second heat absorption threshold, the target water temperature can be adjusted to a third temperature value, and the third temperature value is less than the second temperature value.

[0017] In an optional implementation, the 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:

[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 a 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 a 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 implementation, 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 amount between the coolant and the battery and the current self-heating of the battery.

[0027] This optional implementation manner 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 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, thereby being able to calculate the current total heat absorption of the battery based on the heat exchange amount between the coolant and the battery and the current self-heating of the battery.

[0028] In an optional embodiment, the calculation formula corresponding to 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 amount 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, used 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 turned on when a minimum temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and heating is stopped when a 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 used to dynamically adjust the target water temperature based on the current total heat absorption of the battery, and heat the battery with the target water temperature, wherein the target water temperature corresponds to the temperature rise rate of the battery.

[0043] The device of the second aspect of the present application can dynamically adjust 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 by obtaining the current SOC of the battery and calculating the current total heat absorption of the battery, wherein the heating is turned on when the lowest temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and the heating is exited when the lowest temperature of the battery is greater than or equal to the upper limit of the battery heating threshold, and 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 corresponding to the current total heat absorption of the battery, avoiding slow heating and long charging time caused by too small temperature rise rate, and large temperature difference and short service life caused by too large temperature rise rate. At the same time, by controlling the heating threshold of the battery 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, taking into account both reducing charging time and reducing heating energy consumption.

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

[0045] Processor; and

[0046] The 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 one of the aforementioned embodiments.

[0047] The electronic device of the third aspect of the present application can dynamically adjust the target water temperature for heating by executing the dynamic heating control method for low-temperature battery charging, so that the temperature rise rate of the battery dynamically corresponds to the current total heat absorption of the battery, avoiding slow heating and longer charging time caused by too small a temperature rise rate, and large temperature difference and shorter service life caused by too large a temperature rise rate. At the same time, by controlling the heating threshold of the battery 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, 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 can dynamically adjust the target water temperature for heating by executing the dynamic heating control method for low-temperature charging of the battery, so that the temperature rise rate of the battery dynamically corresponds to the current total heat absorption of the battery, avoiding slow heating and longer charging time due to too small a temperature rise rate, and large temperature difference and shorter service life due to too large a temperature rise rate. At the same time, by controlling the heating threshold of the battery 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, 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 drawings required for use in the embodiments of the present application will be briefly introduced below. 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 related drawings can be obtained based on these drawings without paying creative work.

[0051] Figure 1 It 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 It is a structural schematic 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 It is a structural schematic 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] Embodiment 1

[0056] See also Figure 1 , Figure 1 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 of the battery heating threshold and the upper limit of the battery heating threshold based on the current SOC of the battery, wherein heating is turned on when the lowest temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and heating is stopped when the lowest temperature of the battery 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 with 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 can dynamically adjust 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 by obtaining the current SOC of the battery and calculating the current total heat absorption of the battery, wherein the heating is turned on when the lowest temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and the heating is exited when the lowest temperature of the battery is greater than or equal to the upper limit of the battery heating threshold, and 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 corresponding to the current total heat absorption of the battery, avoiding slow heating and long charging time caused by too small temperature rise rate, and large temperature difference and short service life caused by too large temperature rise rate. At the same time, by controlling the heating threshold of the battery 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, 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 the 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, it is necessary to use 50 degrees Celsius water temperature to continuously heat the battery, then the target water temperature refers to 50 degrees Celsius.

[0065] In the embodiment of the present application, the target water temperature has an initial value. When it is detected that the battery starts to charge, the target water temperature Tf and the heating state N are initialized, and the initial value of the target water temperature Tf is set to Tf=Tf0, and the initial value of the heating state N is set to N=0. Further, steps 101-103 are a dynamic process, wherein, if the battery is turned on for the first time after the start of charging, the heating is first turned on according to the set initial value of the target water temperature Tf=Tf0, and then the value of the target water temperature Tf is dynamically adjusted according to steps 101-103, and then the heating is continued according to the adjusted target water temperature. And after judging that the heating needs to be turned on, the value of the heating state N is set to N=1. If the battery is not turned on for the first time during the charging process, the heating is turned on again according to the target water temperature Tf when the heating was last exited, and then the value of the target water temperature Tf is dynamically adjusted according to steps 101-103, and then the heating is continued according to the adjusted target water temperature. And after judging that the heating needs to be turned on, 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, the target water temperature is adjusted 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 less than the second temperature value.

[0070] This optional implementation 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, when the current total heat absorption of the battery is greater than the second heat absorption threshold, the target water temperature can be adjusted to a third temperature value, and the third temperature value is less than the second temperature value.

[0071] For the above optional implementation, if the current total heat absorption of the battery Pall is less than or equal to the first heat absorption threshold P1, the target water temperature Tf=Tf1 is adjusted, and heating is continued at the new target water temperature Tf1; if the current total heat absorption of the battery 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=Tf2 is adjusted, and heating is continued at the new target water temperature Tf2; if the current total heat absorption of the battery Pall is greater than the second heat absorption threshold P2, the target water temperature Tf=Tf3 is adjusted, and heating is continued at the new target water temperature Tf3. Among them, 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 smaller the target water temperature is set, and the smaller the current total heat absorption of the battery, the larger 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, according to the current battery inlet water temperature and the target water temperature Tf, the PID feedback control method is used to gradually heat the inlet water temperature to the target water temperature and always maintain it near the target water temperature until the heating is stopped or the target water temperature jumps to the next target water temperature. In the 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 inlet water temperature is heated to the target water temperature by automatically adjusting the PTC heating power, and always maintained 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 amount / time interval), and then the target water temperature is adjusted according to the battery temperature rise rate, thereby controlling the battery temperature rise rate 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 untimely control effect of this control method, which may cause the battery temperature rise rate to exceed the appropriate range, making it difficult to accurately control the battery temperature rise rate. The present patent uses a method of adjusting the target water temperature according to the current total heat absorption of the battery, thereby realizing the control of 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, causing the heating to be too long, and the charging time to be too long, or the battery temperature difference from being too large, and the service life from being too short.

[0075] For the above optional implementation, the first heat absorption threshold value P1 is 5000W, the second heat absorption threshold value 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 the 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, 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, 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.

[0081] For the above optional implementation, as an example, the first SOC threshold and the second SOC threshold are represented by H1 and H2 respectively, and the first value, the second value, the third value, the fourth value, the fifth value and the sixth value 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=T1 is set, and the heating threshold upper limit Thigh=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=T3 is set, and the heating threshold upper limit Thigh=T4; if the current SOC is greater than the second SOC threshold H2, the battery heating threshold lower limit Tlow=T5 is set, and the heating threshold upper limit Thigh=T6. Among them, the battery heating threshold lower limit is the minimum temperature for turning on the battery heating, and the battery heating is turned on when the battery minimum temperature is less than or equal to the battery heating threshold lower limit; the battery heating threshold upper limit is the maximum temperature for exiting the battery heating, and the battery heating is exited when the battery minimum temperature is greater than or equal to the battery heating threshold upper limit. 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 be larger. 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 implementation, 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 to charge 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's 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, such as SOC from 60% to 100%. When the battery is first charged from a higher SOC to a high SOC (for example, SOC 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 the 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%-100%), the battery's self-heating will further decrease, and the self-heating may be lower than the external heat exchange, resulting in a phenomenon of continuous temperature decrease. To avoid the situation where the charging rate is reduced due to the decrease in battery temperature after a high SOC, a higher heating threshold than that at a low SOC and a high SOC should be used for timely intervention, so that heating can be started earlier after a high SOC to prevent the battery temperature from continuing to decrease; (3) When the battery starts to charge from a high SOC, for example, when 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. The battery temperature can only be raised to an appropriate range by heating the battery to a higher heating threshold and then stopping heating to further increase the charging rate.

[0085] In the embodiment of the present application, as an optional implementation, the step: 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] Based on the heat exchange between the coolant and the battery and the current self-heating of the battery, the current total heat absorption of the battery is calculated.

[0090] This optional implementation 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 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, thereby calculating the current total heat absorption of the battery based on the heat exchange amount 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-heat of the battery is:

[0092] Pcell=I 2 *R;

[0093] Among them, Pcell represents the current spontaneous heat 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-heat of the battery, the calculation formula corresponding to 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 calculation formula corresponding to the heat exchange 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:

[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, 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, 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, the heating is exited and the heating state of the battery 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 the heating is exited prematurely due to misjudgment when the battery is already in the heating-on state and the minimum temperature of the battery 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. This ensures that the heating is normally exited only after the minimum temperature of the battery 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 the heating, and the heating is not turned on, and it is determined whether to continue to execute the next heating control cycle or to end the charging.

[0108] This optional implementation acquires 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] Embodiment 2

[0110] See also Figure 2 , Figure 2 is a structural schematic diagram of a dynamic heating control device for low-temperature charging of a battery disclosed in an embodiment of the present application, such as 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 acquire 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 turned on when a minimum temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and heating is stopped when a minimum temperature of the battery is greater than or equal to the upper limit of the battery heating threshold;

[0113] The second dynamic adjustment module 203 is used to dynamically adjust the target water temperature based on the current total heat absorption of the battery, and heat the battery with 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 can dynamically adjust 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 by obtaining the current SOC of the battery and calculating the current total heat absorption of the battery, wherein the heating is turned on when the lowest temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and the heating is exited when the lowest temperature of the battery is greater than or equal to the upper limit of the battery heating threshold, and 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 corresponding to the current total heat absorption of the battery, avoiding slow heating and long charging time caused by too small temperature rise rate, and large temperature difference and short service life caused by too large temperature rise rate. At the same time, by controlling the heating threshold of the battery 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, taking into account both reducing charging time and reducing heating energy consumption.

[0115] Embodiment 3

[0116] See also Figure 3 , Figure 3 is a schematic diagram of the structure 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, and 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 embodiment of the present application can dynamically adjust the target water temperature for heating by executing the dynamic heating control method for low-temperature battery charging, so that the temperature rise rate of the battery dynamically corresponds to the current total heat absorption of the battery, avoiding slow heating and longer charging time caused by too small a temperature rise rate, and large temperature difference and shortened service life caused by too large a temperature rise rate. At the same time, by controlling the heating threshold of the battery 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, taking into account both reducing charging time and reducing heating energy consumption.

[0120] Embodiment 4

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

[0122] The storage medium of the embodiment of the present application can dynamically adjust the target water temperature for heating by executing the dynamic heating control method for low-temperature battery charging, so that the temperature rise rate of the battery dynamically corresponds to the current total heat absorption of the battery, avoiding slow heating and longer charging time caused by too small a temperature rise rate, and large temperature difference and shortened service life caused by too large a temperature rise rate. At the same time, by controlling the heating threshold of the battery 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, taking into account both reducing charging time and reducing heating energy consumption.

[0123] In the embodiments provided in the present 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 interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0124] In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on 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 the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may 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 can essentially be embodied in the form of a software product, or in other words, the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM) random access memory (RAM), disk or optical disk, and other media that can store program codes.

[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 such actual relationship or order between these entities or operations.

[0128] The above are only embodiments of the present application and are not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in 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 turned on when a minimum temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and heating is stopped when a minimum temperature of the battery is greater than or equal to the upper limit of the battery heating threshold; 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.

2. The method according to claim 1, characterized in that 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 less than the second temperature value.

3. The method according to claim 1, characterized in that The 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: 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, characterized in that The calculating the current total heat absorption of the battery comprises: 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; The current total heat absorption of the battery is calculated based on the heat exchange amount between the coolant and the battery and the current self-heating of the battery.

5. The method according to claim 4, characterized in that The calculation formula corresponding to 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 is: Pf = Qm*Cp*ΔT; Wherein, Pf represents the heat exchange amount 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.

6. The method according to claim 1, characterized in that 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.

7. The method according to claim 1, characterized in that 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.

8. A dynamic heating control device for low-temperature charging of a battery, characterized in that: The device comprises: An acquisition module, used 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 turned on when a minimum temperature of the battery is less than or equal to the lower limit of the battery heating threshold, and heating is stopped when a minimum temperature of the battery is greater than or equal to the upper limit of the battery heating threshold; The second dynamic adjustment module is used to dynamically adjust the target water temperature based on the current total heat absorption of the battery, and heat the battery with the target water temperature, wherein the target water temperature corresponds to the temperature rise rate of the battery.

9. 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 7.

10. 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 as described in any one of claims 1 to 7.

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