A control method and system for dynamic regulation of vehicle battery temperature

Abstract

The present invention provides a control method and system for dynamic regulation of vehicle battery temperature, comprising the following steps: obtaining the current speed of the vehicle, the current ambient temperature of the vehicle battery, and battery status information, wherein the battery status information includes the current charge and discharge state, the current battery cell temperature, the change in battery cell temperature, and the energy required when the battery cell temperature changes; determining the ambient temperature impact value Y, the energy calculation value Z, the energy value E taken away by heat convection at the current vehicle speed and ambient temperature, and the battery thermal inertia compensation value G according to the battery's ambient temperature and battery status information; obtaining the adjustment value F according to the formula and adjusting the battery management of the thermal management system according to the adjustment value F. The present invention determines the temperature change trend of the current battery pack by obtaining various values ​​of the vehicle battery, and performs thermal management on the battery in advance according to the trend, thereby solving the problem that the thermal management control in the prior art is passive and has hysteresis.

Description

Technical Field

[0001] The present invention relates to the technical field of power battery thermal management systems, and in particular to a control method and system for dynamically regulating vehicle battery temperature. Background Art

[0002] The current battery thermal management control method is based on the battery controller BMS target temperature request; the battery controller BMS itself performs calculations based on the battery heat dissipation or heating requirements; thermal management control is a passive response, with defects such as large lag, large fluctuations in energy management, and inability to perform dynamic adjustments based on energy assessment. In addition, the current battery thermal management control method cannot accurately assess the battery's energy requirements and heat loss in the environment, etc., under different external environments and different vehicle driving conditions. Summary of the invention

[0003] An object of the present invention is to provide a control method for dynamically adjusting the temperature of a vehicle battery, so that the vehicle can actively perform thermal management on the battery according to the state of the vehicle and the state of the battery.

[0004] In particular, the present invention provides a control method for dynamically adjusting the temperature of a vehicle battery, which is used to adjust the thermal management system when the vehicle requires thermal management, comprising the following steps:

[0005] Obtain the current speed of the vehicle, the current ambient temperature of the vehicle battery, and battery status information, wherein the battery status information includes the current charge and discharge status, the current battery cell temperature, the battery cell temperature change, and the energy required when the battery cell temperature changes;

[0006] Determine an ambient temperature impact value Y according to the ambient temperature and the battery status information;

[0007] Determine an energy calculation value Z according to the current charge and discharge state and the current battery core temperature;

[0008] Determine, according to the current vehicle speed and the ambient temperature, the energy value E removed by heat convection at the current vehicle speed and the ambient temperature;

[0009] Determine the battery thermal inertia compensation amount G according to the battery core temperature change and the energy required when the battery core temperature changes;

[0010] Performing weighted summation on the ambient temperature impact value Y, the energy calculation value Z, the energy value E, and the thermal inertia compensation amount G to obtain an adjustment value;

[0011] The battery management of the thermal management system is adjusted according to the adjustment value.

[0012] Further, in the step of performing weighted summation of the ambient temperature impact value Y, the energy calculation value Z, the energy value E, and the thermal inertia compensation amount G to obtain the adjustment value, the adjustment value F is calculated according to the following formula 1:

[0013] F=∑(aY+bZ+cE+dG) Formula 1

[0014] Among them, a, b, c, and d are calibration coefficients respectively.

[0015] Furthermore, in the step of determining the energy value E carried away by heat convection at the current vehicle speed and the ambient temperature based on the current vehicle speed and the ambient temperature, the energy value E is calculated according to the formula E=V*T, wherein V represents the current speed of the vehicle and T represents the ambient temperature.

[0016] Furthermore, in the step of determining the battery thermal inertia compensation amount G based on the battery cell temperature change and the energy required when the battery cell temperature changes, the battery thermal inertia compensation amount G is calculated according to the formula G=△T1*Q, wherein △T1 represents the battery cell temperature change, and Q represents the energy required when the battery cell temperature changes.

[0017] Furthermore, the step of determining the ambient temperature impact value Y according to the ambient temperature and the battery status information further includes the following steps:

[0018] Acquire the temperature conduction heat value of the current environment according to the ambient temperature;

[0019] The Y value is obtained by querying a first mapping relationship table between the temperature conduction heat value and the battery status information.

[0020] Further, the step of adjusting the battery management of the thermal management system according to the adjustment value F also includes the following steps:

[0021] The adjusted speed n of the vehicle compressor is calculated according to the adjustment value F by the following formula:

[0022] n=F / compressor cooling capacity curve

[0023] The compressor refrigeration capacity curve is the compressor bench test value;

[0024] The vehicle compressor is regulated as a function of the calculated rotational speed n.

[0025] Furthermore, the method further includes: calculating the flow rate M of the vehicle water pump according to the following formula 5:

[0026] M=F / (C*△T2)

[0027] Where: △T2 is the difference between the battery target temperature and the current coolant temperature, and C is the specific heat capacity of ethylene glycol.

[0028] Furthermore, it also includes:

[0029] The adjustment value F is used as the power output by the vehicle heater, and the vehicle heater is controlled to output according to the adjustment value F.

[0030] The present invention also discloses a control system for dynamic temperature regulation of a vehicle battery, comprising a control device, wherein the control device comprises a memory and a processor, wherein a control program is stored in the memory, and when the control program is executed by the processor, it is used to implement the above-mentioned control method for dynamic temperature regulation of a vehicle battery.

[0031] The present invention determines the temperature change trend of the current battery pack by acquiring the current vehicle speed, the current ambient temperature of the vehicle battery, and battery status information, wherein the battery status information includes various values ​​such as the current charge and discharge state, the current battery cell temperature, the battery cell temperature change, and the energy required when the battery cell temperature changes, and performs thermal management of the battery in advance according to the trend, thereby solving the problem that the thermal management control in the prior art is passive and has hysteresis.

[0032] Furthermore, the present invention ensures the stability of battery temperature by actively predicting battery thermal management in advance, effectively reducing fluctuations in battery thermal management. In addition, active thermal management can also achieve the characteristics of fast responsiveness, good followability and high stability.

[0033] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0035] Figure 1 is a schematic diagram of a flow structure according to an embodiment of the present invention;

[0036] Figure 2 is a charge-discharge-ambient temperature conduction heat diagram according to an embodiment of the present invention;

[0037] Figure 3 is a diagram of battery cell temperature-discharge multiple-heating according to an embodiment of the present invention;

[0038] Figure 4It is a schematic diagram of the adjustment process structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In one embodiment, Figure 1 As shown, the control method for dynamic temperature regulation of a vehicle battery is used to adjust the thermal management system of the battery when the vehicle battery needs thermal management, and mainly includes the following steps:

[0040] S1: Obtain the current speed of the vehicle, the current ambient temperature of the vehicle battery, and the battery status information. The battery status information includes the current charge and discharge status, the current battery cell temperature, the battery cell temperature change, and the energy required when the battery cell temperature changes;

[0041] S2: Determine the ambient temperature impact value Y according to the ambient temperature and the battery status;

[0042] S3: Determine the energy calculation value Z according to the current charge and discharge state and the current battery cell temperature information;

[0043] S4: determining the energy value E removed by heat convection at the current vehicle speed and ambient temperature according to the current vehicle speed and ambient temperature;

[0044] S5: Determine the battery thermal inertia compensation amount G according to the battery cell temperature change and the energy required when the battery cell temperature changes;

[0045] S6: Calculate the ambient temperature impact value Y, the energy calculation value Z, the energy value E, and the thermal inertia compensation value G according to the following formula 1 to obtain the adjustment value F:

[0046] F=∑(aY+bZ+cE+dG) Formula 1

[0047] Among them, a, b, c, and d are calibration coefficients respectively;

[0048] S7: Adjust the battery management of the thermal management system according to the adjustment value F.

[0049] In this embodiment, the temperature change trend of the current battery pack is determined by obtaining the current vehicle speed, the current ambient temperature of the vehicle battery, and the battery status information, including the current charge and discharge status, the current battery cell temperature, the battery cell temperature change, and the energy required when the battery cell temperature changes. The battery is thermally managed in advance based on the trend, thereby solving the problem that the thermal management control in the prior art is passive and has lags.

[0050] Furthermore, the present invention ensures the stability of battery temperature by actively predicting battery thermal management in advance, effectively reducing fluctuations in battery thermal management. In addition, active thermal management can also achieve the characteristics of fast responsiveness, good followability and high stability.

[0051] In a further embodiment, Figure 2 and Figure 3 As shown, in order to obtain the ambient temperature and battery status to determine the ambient temperature impact value Y, firstly, the temperature conduction heat value of the current environment is obtained according to the ambient temperature, and then the Figure 2 The first mapping relationship table of the temperature conduction heat value and the battery status information shown in the figure obtains the Y value. Similarly, to obtain the energy calculation value Z, the Figure 3 The table shown is obtained by querying.

[0052] In addition, the vehicle's current speed V and the ambient temperature T of the battery pack can be obtained. The current vehicle speed and ambient temperature can be effectively calculated through the formula E=V*T to determine the energy value E carried away by thermal convection at the current vehicle speed and ambient temperature. By calculating the energy value E carried away by thermal convection, the error of the external environment on the internal thermal management of the battery can be effectively reduced, thereby ensuring the accuracy of battery thermal management.

[0053] Furthermore, the battery thermal inertia compensation G can be calculated according to the formula G=△T1*Q, wherein △T1 represents the temperature change of the battery cell, and Q represents the energy required when the battery cell temperature changes. It should be pointed out that Q represents the energy required for each increase or decrease of 1°C in the average temperature of the battery cell, so that the battery thermal inertia compensation G can be calculated.

[0054] In this embodiment, the current temperature change trend of the battery pack is determined by obtaining the ambient temperature and battery status information of the current vehicle battery, wherein the battery status information includes various values ​​such as the current charge and discharge status, the current battery cell temperature, the battery cell temperature change, and the energy required when the battery cell temperature changes. The battery is thermally managed in advance according to the trend, thereby solving the problem that the thermal management control in the prior art is passive and has lag.

[0055] In one embodiment, Figure 1 and Figure 4 As shown, after the adjustment value F is calculated, the battery thermal management system needs to be adjusted. The battery thermal management system consists of multiple parts, and each part needs to be adjusted. The adjustment mainly includes the following steps:

[0056] S71: Calculate the adjusted speed n of the vehicle compressor according to the adjustment value F by the following formula; n=F / compressor cooling capacity curve, where the compressor cooling capacity curve is the compressor bench test value; adjust the vehicle compressor according to the calculated speed n.

[0057] S72: The flow rate M of the vehicle water pump is calculated according to the following formula 5: M=F / (C*△T2) where: △T2 is the difference between the battery target temperature and the current coolant temperature, and C is the specific heat capacity of ethylene glycol.

[0058] S73: Using the adjustment value F as the power output by the vehicle heater, and controlling the vehicle heater to output according to the adjustment value F.

[0059] In this embodiment, the rotation speed of the vehicle compressor, the water pump flow rate and the output power of the vehicle heater are adjusted respectively by adjusting the value F, so that the battery thermal management system can always ensure that the battery pack is in a relatively ideal temperature control condition, effectively ensuring the stability of the battery's working environment.

[0060] Of course, the solvent in step S72 can also be converted into other types of solvents, and it is only necessary to adjust the specific heat capacity value accordingly.

[0061] The present invention also discloses a control system for dynamic temperature regulation of a vehicle battery, including a control device, the control device including a memory and a processor, the memory storing a control program, and the control program, when executed by the processor, is used to implement the above-mentioned control method for dynamic temperature regulation of the vehicle battery.

[0062] At this point, those skilled in the art should recognize that, although multiple exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the content disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all these other variations or modifications.

Claims

1. A control method for dynamic regulation of vehicle battery temperature, characterized in that: Used to adjust the thermal management system when the vehicle requires thermal management, including the following steps: Obtain the current speed of the vehicle, the current ambient temperature of the vehicle battery, and battery status information, wherein the battery status information includes the current charge and discharge status, the current battery cell temperature, the battery cell temperature change, and the energy required when the battery cell temperature changes; Determine an ambient temperature impact value Y according to the ambient temperature and the battery status information; Determine an energy calculation value Z according to the current charge and discharge state and the current battery core temperature; Determine, according to the current vehicle speed and the ambient temperature, the energy value E removed by heat convection at the current vehicle speed and the ambient temperature; Determine the battery thermal inertia compensation amount G according to the battery core temperature change and the energy required when the battery core temperature changes; Performing weighted summation on the ambient temperature impact value Y, the energy calculation value Z, the energy value E, and the thermal inertia compensation amount G to obtain an adjustment value; The battery management of the thermal management system is adjusted according to the adjustment value.

2. The control method according to claim 1, characterized in that: In the step of performing weighted summation of the ambient temperature impact value Y, the energy calculation value Z, the energy value E, and the thermal inertia compensation amount G to obtain the adjustment value, the adjustment value F is calculated according to the following formula 1: F=∑(aY+bZ+cE+dG) Formula 1 Among them, a, b, c, and d are calibration coefficients respectively.

3. The control method according to claim 1, characterized in that: In the step of determining the energy value E carried away by heat convection at the current vehicle speed and the ambient temperature based on the current vehicle speed and the ambient temperature, the energy value E is calculated according to the formula E=V*T, wherein V represents the current vehicle speed and T represents the ambient temperature.

4. The control method according to claim 3, characterized in that: In the step of determining the battery thermal inertia compensation amount G based on the battery cell temperature change and the energy required when the battery cell temperature changes, the battery thermal inertia compensation amount G is calculated according to the formula G=△T1*Q, wherein △T1 represents the battery cell temperature change, and Q represents the energy required when the battery cell temperature changes.

5. The control method according to claim 4, characterized in that: The step of determining the ambient temperature impact value Y according to the ambient temperature and the battery status information also includes the following steps: Acquire the temperature conduction heat value of the current environment according to the ambient temperature; The Y value is obtained by querying a first mapping relationship table between the temperature conduction heat value and the battery status information.

6. The control method according to any one of claims 1 to 5, characterized in that: The step of adjusting the battery management of the thermal management system according to the adjustment value F also includes the following steps: The adjusted speed n of the vehicle compressor is calculated according to the adjustment value F by the following formula: n=F / compressor cooling capacity curve The compressor refrigeration capacity curve is the compressor bench test value; The vehicle compressor is regulated as a function of the calculated rotational speed n.

7. The control method according to claim 6, characterized in that: Also includes: The flow rate M of the vehicle water pump is calculated according to the following formula 5: M=F / (C*△T2) Where: △T2 is the difference between the battery target temperature and the current coolant temperature, and C is the specific heat capacity of ethylene glycol.

8. The control method according to claim 7, characterized in that: Also includes: The adjustment value F is used as the power output by the vehicle heater, and the vehicle heater is controlled to output according to the adjustment value F.

9. A control system for dynamic temperature regulation of a vehicle battery, characterized in that: It comprises a control device, which comprises a memory and a processor. The memory stores a control program, and when the control program is executed by the processor, it is used to implement the control method for dynamic regulation of vehicle battery temperature according to any one of claims 1-8.

Images