Electronic expansion valve control method and device and controller

Abstract

The invention relates to an electronic expansion valve control method and device and a controller. The method comprises the steps that the environment temperature and vehicle speed information of a target vehicle at the current refrigeration moment are obtained, and the battery refrigeration duration of the target vehicle is obtained; the battery refrigeration duration is the duration from the initial refrigeration moment of the battery of the target vehicle to the current refrigeration moment; according to the environment temperature and the vehicle speed information, the basic opening degree and the composite opening degree of an electronic expansion valve of the target vehicle at the current refrigeration moment are obtained, and according to the vehicle speed information, the opening degree adjusting speed of the electronic expansion valve at the current refrigeration moment is obtained; according to the basic opening degree, the composite opening degree, the opening degree adjusting speed and the battery refrigeration duration, the target opening degree of the electronic expansion valve at the current refrigeration moment is obtained; the target opening degree is used for controlling the opening degree of the electronic expansion valve at the current refrigeration moment to be adjusted to the target opening degree. By means of the method, the opening adjustment delay of the electronic expansion valve can be reduced.

Description

Technical Field

[0001] The present application relates to the field of new energy vehicle technology, and in particular to an electronic expansion valve control method, device and controller. Background Art

[0002] With the development of new energy vehicle technology, a technology that uses liquid cooling to maintain battery temperature has emerged. By controlling the opening of the electronic expansion valve, EXV, the refrigerant flow entering the battery cooler can be controlled to accurately control the battery temperature. In related technologies, the method for controlling the opening of the electronic expansion valve is usually based on the superheat, that is, the difference between the actual battery temperature and the ideal temperature, combined with the PI algorithm to achieve the opening adjustment of the electronic expansion valve.

[0003] However, at the beginning of cooling, when the various components in the system have not yet reached a stable working state, the heat generated by the battery needs to be transferred to the refrigerant through the cold plate, and the refrigerant then dissipates the heat to the external environment. This series of heat transfer processes involves multiple links, each of which has a certain thermal resistance and heat capacity, so that it takes a certain amount of time for the heat to be generated and finally dissipated. Therefore, during the startup phase of the cooling system, the superheat usually exceeds the set target range, and it takes a long time to adjust so that the superheat gradually stabilizes. In addition, due to the large thermal inertia between the various parts of the system, there is also a lag in the opening adjustment of the electronic expansion valve, which means that even if the controller makes adjustments based on the current temperature feedback, the actual temperature change will have a significant delay. It can be seen that the current method of adjusting the opening of the electronic expansion valve based on superheat combined with the PI algorithm has a delay. Summary of the invention

[0004] Based on this, it is necessary to provide an electronic expansion valve control method, device, controller, computer-readable storage medium and computer program product that can reduce the opening adjustment delay of the electronic expansion valve in order to address the above technical problems.

[0005] In a first aspect, the present application provides an electronic expansion valve control method, comprising:

[0006] Acquire the ambient temperature and vehicle speed information of the target vehicle at the current cooling time, and acquire the battery cooling time of the target vehicle; the battery cooling time is the time from the battery start cooling time of the target vehicle to the current cooling time;

[0007] According to the ambient temperature and the vehicle speed information, obtaining the basic opening and the composite opening of the electronic expansion valve of the target vehicle at the current cooling moment, and according to the vehicle speed information, obtaining the opening adjustment rate of the electronic expansion valve at the current cooling moment;

[0008] The target opening of the electronic expansion valve at the current cooling moment is obtained according to the basic opening, the compound opening, the opening adjustment rate and the battery cooling time; the target opening is used to control the opening of the electronic expansion valve at the current cooling moment to be adjusted to the target opening.

[0009] In one of the embodiments, obtaining the opening adjustment rate of the electronic expansion valve at the current refrigeration moment based on the vehicle speed information includes: obtaining the basic opening adjustment rate of the electronic expansion valve at the current refrigeration moment based on the vehicle speed information; obtaining a first correction coefficient and a second correction coefficient for correcting the basic opening adjustment rate at the current refrigeration moment; and correcting the basic opening adjustment rate using the first correction coefficient and the second correction coefficient to obtain the opening adjustment rate.

[0010] In one embodiment, the first correction coefficient is obtained by the following steps: obtaining the refrigeration control cycle in which the current refrigeration moment is located, and obtaining the current current fluctuation information and the current vehicle speed fluctuation information of the refrigeration control cycle; the current current fluctuation information is used to characterize the fluctuation of the battery current of the target vehicle in the refrigeration control cycle, and the current vehicle speed fluctuation information is used to characterize the fluctuation of the vehicle speed of the target vehicle in the refrigeration control cycle; obtaining a pre-constructed first calibration relationship; the first calibration relationship stores the correspondence between different current fluctuation information and vehicle speed fluctuation information and different first correction coefficients; wherein the first correction coefficient is negatively correlated with the current fluctuation information and the vehicle speed fluctuation information; using the correction coefficient corresponding to the current current fluctuation information and the current vehicle speed fluctuation information in the first calibration relationship as the first correction coefficient for correcting the basic opening adjustment rate in the current refrigeration moment.

[0011] In one embodiment, the second correction coefficient is obtained by the following steps: obtaining the current battery current value of the target vehicle at the current cooling moment, and a pre-constructed second calibration relationship; the second calibration relationship stores the correspondence between different battery current values ​​and different current calibration parameters; wherein the current calibration parameter is positively correlated with the battery current value; from the second calibration relationship, obtaining the current current calibration parameter corresponding to the current battery current value; and obtaining the second correction coefficient for correcting the basic opening adjustment rate at the current cooling moment according to the current battery current value and the current current calibration parameter.

[0012] In one of the embodiments, before obtaining the current current calibration parameter corresponding to the current battery current value from the second calibration relationship, it also includes: when the current battery current value does not reach the minimum battery current value stored in the second calibration relationship, updating the current battery current value to the minimum battery current value.

[0013] In one of the embodiments, obtaining the basic opening adjustment rate of the electronic expansion valve at the current cooling moment based on the vehicle speed information includes: obtaining a pre-constructed third calibration relationship; the third calibration relationship stores the correspondence between different vehicle speed intervals and different basic opening adjustment rates; wherein the basic opening adjustment rate is positively correlated with the vehicle speed interval; obtaining the target vehicle speed interval in which the vehicle speed information is located, and using the basic opening adjustment rate corresponding to the target vehicle speed interval in the third calibration relationship as the basic opening adjustment rate at the current cooling moment.

[0014] In one of the embodiments, obtaining the basic opening of the electronic expansion valve of the target vehicle at the current cooling moment based on the ambient temperature and the vehicle speed information includes: obtaining a pre-constructed fourth calibration relationship; the fourth calibration relationship stores the correspondence between different ambient temperatures and vehicle speed information and different basic openings; and using the basic opening corresponding to the ambient temperature and vehicle speed information at the current cooling moment in the fourth calibration relationship as the basic opening of the electronic expansion valve at the current cooling moment.

[0015] In one of the embodiments, the composite opening is obtained by the following steps: obtaining a pre-constructed fifth calibration relationship; the fifth calibration relationship stores the correspondence between different ambient temperatures and vehicle speed information and different composite openings; and using the composite opening corresponding to the ambient temperature and vehicle speed information at the current cooling moment in the fifth calibration relationship as the composite opening of the electronic expansion valve at the current cooling moment.

[0016] In one of the embodiments, the target opening of the electronic expansion valve at the current cooling moment is obtained according to the basic opening, the compound opening, the opening adjustment rate and the battery cooling time, including: obtaining the cooling working mode of the target vehicle at the current cooling moment, and obtaining the temperature difference information of the evaporator of the target vehicle at the current cooling moment; the temperature difference information represents the difference between the actual temperature and the target temperature of the evaporator at the current cooling moment; the evaporator is used to adjust the temperature of the passenger compartment of the target vehicle; according to the cooling working mode, the passenger compartment comfort compensation coefficient pre-set for the passenger compartment is obtained, and the opening loss of the electronic expansion valve at the current cooling moment is obtained by using the passenger compartment comfort compensation coefficient and the temperature difference information; the target opening is obtained according to the basic opening, the compound opening, the opening adjustment rate, the battery cooling time and the opening loss.

[0017] In one embodiment, the refrigeration working mode includes: a first working mode for characterizing that the passenger compartment is cooled preferentially, a second working mode for cooling the battery of the target vehicle preferentially, and a third working mode for cooling only the battery; obtaining a passenger compartment comfort compensation coefficient pre-set for the passenger compartment according to the refrigeration working mode includes: when the refrigeration working mode is the first working mode, setting the passenger compartment comfort compensation coefficient to a first compensation coefficient; when the refrigeration working mode is the second working mode, setting the passenger compartment comfort compensation coefficient to a second compensation coefficient; wherein the second compensation coefficient is less than the first compensation coefficient; when the refrigeration working mode is the third working mode, setting the passenger compartment comfort compensation coefficient to zero.

[0018] In one of the embodiments, obtaining the refrigeration working mode of the target vehicle at the current refrigeration moment includes: when there is a refrigeration demand in the passenger compartment and the battery cell temperature exceeds a first temperature threshold but does not exceed a second temperature threshold, determining that the refrigeration working mode is the first working mode; the second temperature threshold is greater than the first temperature threshold; when there is a refrigeration demand in the passenger compartment and the battery cell temperature exceeds the second temperature threshold but does not exceed a third temperature threshold, determining that the refrigeration working mode is the second working mode; the third temperature threshold is greater than the second temperature threshold; when the battery cell temperature exceeds the third temperature threshold, or when there is no refrigeration demand in the passenger compartment and the battery cell temperature exceeds the first temperature threshold, determining that the refrigeration working mode is the third working mode.

[0019] In a second aspect, the present application further provides an electronic expansion valve control device, comprising:

[0020] A vehicle information acquisition module is used to acquire the ambient temperature and vehicle speed information of the target vehicle at the current cooling time, and acquire the battery cooling time of the target vehicle; the battery cooling time is the time from the battery start cooling time of the target vehicle to the current cooling time;

[0021] an adjustment information acquisition module, configured to acquire a basic opening and a composite opening of the electronic expansion valve of the target vehicle at the current cooling moment according to the ambient temperature and the vehicle speed information, and to acquire an opening adjustment rate of the electronic expansion valve at the current cooling moment according to the vehicle speed information;

[0022] A target opening acquisition module is used to obtain the target opening of the electronic expansion valve at the current cooling moment according to the basic opening, the compound opening, the opening adjustment rate and the battery cooling time; the target opening is used to control the opening of the electronic expansion valve at the current cooling moment to be adjusted to the target opening.

[0023] In a third aspect, the present application further provides a controller comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method described in any one of the embodiments of the first aspect when executing the computer program.

[0024] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method described in any one of the embodiments of the first aspect.

[0025] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of the method described in any one of the embodiments of the first aspect.

[0026] The above-mentioned electronic expansion valve control method, device, controller, storage medium and computer program product obtain the ambient temperature and vehicle speed information of the target vehicle at the current cooling time, and obtain the battery cooling time of the target vehicle; the battery cooling time is the time from the battery start cooling time of the target vehicle to the current cooling time; according to the ambient temperature and vehicle speed information, the basic opening and compound opening of the electronic expansion valve of the target vehicle at the current cooling time are obtained, and according to the vehicle speed information, the opening adjustment rate of the electronic expansion valve at the current cooling time is obtained; according to the basic opening, compound opening, opening adjustment rate and battery cooling time, the target opening of the electronic expansion valve at the current cooling time is obtained; the target opening is used to control the opening of the electronic expansion valve at the current cooling time to be adjusted to the target opening. The present application can control the opening of the electronic expansion valve of the target vehicle after the target vehicle enters the battery cooling mode, wherein the control method is to collect the ambient temperature, vehicle speed and battery cooling duration of the target vehicle at the current moment, thereby obtaining the basic opening and compound opening of the electronic expansion valve at the current moment through the ambient temperature and vehicle speed, and obtaining the opening adjustment rate of the electronic expansion valve at the current moment through the vehicle speed, so that the basic opening, compound opening, opening adjustment rate and battery cooling duration at the current moment can be used to obtain the target opening for controlling the electronic expansion valve. The control method does not need to adopt the superheat-based combined PI algorithm to realize the opening adjustment of the electronic expansion valve, so the opening adjustment delay of the electronic expansion valve can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A schematic flow chart of an electronic expansion valve control method in one embodiment;

[0029] Figure 2 It is a schematic diagram of a flow chart of obtaining the opening adjustment rate at the current cooling moment in one embodiment;

[0030] Figure 3 A schematic diagram of a flow chart for obtaining a first correction coefficient in one embodiment;

[0031] Figure 4 A schematic diagram of a flow chart for obtaining a second correction coefficient in one embodiment;

[0032] Figure 5 A schematic diagram of a flow chart for obtaining a target opening degree at the current cooling moment in an embodiment;

[0033] Figure 6 A schematic diagram of the relationship between cooling time and electronic expansion valve opening adjustment in one embodiment;

[0034] Figure 7 A schematic diagram of the execution logic of the single and double refrigeration priority of the passenger compartment in one embodiment;

[0035] Figure 8 is a structural block diagram of an electronic expansion valve control device in one embodiment;

[0036] Fig. 9 FIG. 4 is a diagram showing the internal structure of a controller in one embodiment. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0038] In one embodiment, Figure 1 As shown, a method for controlling an electronic expansion valve is provided. This embodiment is illustrated by applying the method to a controller for controlling an electronic expansion valve in an automobile. In this embodiment, the method includes the following steps:

[0039] Step S101, obtaining the ambient temperature and vehicle speed information of the target vehicle at the current cooling time, and obtaining the battery cooling time of the target vehicle; the battery cooling time is the time from the battery starting cooling time of the target vehicle to the current cooling time.

[0040] The target vehicle refers to a vehicle that needs to control the electronic expansion valve to cool the vehicle battery and the passenger compartment. The electronic expansion valve can be connected to the refrigeration system, and the flow of the refrigerant between the condenser and the evaporator can be controlled, that is, the electronic expansion valve can control the flow of the refrigerant flowing into the evaporator by controlling the opening, thereby absorbing the heat in the surrounding environment (such as the passenger compartment or the battery) to achieve a refrigeration effect. The electronic expansion valve can be composed of a valve body, an electric control mechanism, a sensor interface and a control unit. The valve body is used to accommodate and guide the flow of the refrigerant. The electric control mechanism can control the opening and closing of the valve through a motor or other driving method to adjust the refrigerant flow. The sensor interface can be connected to temperature and pressure sensors. These sensors monitor the system status in real time and provide feedback information to the control unit. The control unit can calculate and adjust the opening of the valve based on the sensor data to achieve precise control.

[0041] The current cooling time refers to the current time after the battery cooling mode is turned on, the starting cooling time refers to the time when the battery cooling mode is turned on, and the battery cooling duration refers to the time when the battery cooling mode is turned on. It can be used to represent the time between the time when the battery cooling mode is turned on and the current time, that is, the time from the starting cooling time to the current cooling time.

[0042] Specifically, after the target vehicle starts the battery cooling mode, the controller can obtain in real time the temperature of the driving environment of the target vehicle at the current cooling moment, that is, the ambient temperature, and the driving speed of the target vehicle, that is, the vehicle speed information. At the same time, it can also obtain in real time the battery cooling time when the target vehicle enters the battery cooling mode.

[0043] Step S102, obtaining the basic opening and compound opening of the electronic expansion valve of the target vehicle at the current cooling moment according to the ambient temperature and vehicle speed information, and obtaining the opening adjustment rate of the electronic expansion valve at the current cooling moment according to the vehicle speed information.

[0044] The basic opening refers to the basic opening information of the electronic expansion valve of the target vehicle. This opening is only used to meet the most basic cooling needs of the battery. However, when the vehicle is driving fast or the external ambient temperature is high, the battery generates a lot of heat and the basic opening cannot meet the battery cooling needs. Therefore, it is necessary to introduce a composite opening to compensate for the basic opening to ensure that the battery cooling needs are met. The opening adjustment rate is used to characterize the adjustment rate of the electronic expansion valve opening. Since the battery charging and discharging current is related to the battery's heat generation rate, and the vehicle speed is a key factor affecting the battery power consumption, that is, the vehicle speed can reflect the size of the battery current. Therefore, in order to ensure that the opening adjustment rate of the electronic expansion valve can match the battery heat generation rate, the opening adjustment rate can be determined by the vehicle speed.

[0045] Specifically, after obtaining the ambient temperature and vehicle speed information, the controller can obtain the basic opening and compound opening at the current cooling moment according to the ambient temperature and vehicle speed information. For example, the basic opening and compound opening can be calculated by the ambient temperature and vehicle speed information, or the basic opening and compound opening can be obtained by looking up a table. At the same time, the opening adjustment rate of the electronic expansion valve at the current cooling moment can be obtained according to the vehicle speed information. Similar to the method of obtaining the basic opening and compound opening, the opening adjustment rate can be obtained by calculation or by looking up a table or other methods.

[0046] Step S103, obtaining the target opening of the electronic expansion valve at the current cooling moment according to the basic opening, the compound opening, the opening adjustment rate and the battery cooling time; the target opening is used to control the opening of the electronic expansion valve at the current cooling moment to be adjusted to the target opening.

[0047] The target opening is the target opening adjustment target of the electronic expansion valve of the target vehicle at the current cooling time, and the target opening can be calculated by the basic opening, compound opening, opening adjustment rate and battery cooling time. Specifically, after obtaining the basic opening, compound opening, opening adjustment rate and battery cooling time, the controller can calculate the target opening of the electronic expansion valve at the current cooling time based on the above information, and then send the target opening to the regulating mechanism for adjusting the opening of the electronic expansion valve, so that the regulating mechanism adjusts the opening of the electronic expansion valve at the current cooling time to the target opening, so as to achieve precise control of the electronic expansion valve, so as to achieve the purpose of accurately controlling the battery temperature. Among them, the calculation of the target opening can be obtained according to the correspondence between the pre-constructed target opening and the basic opening, compound opening, opening adjustment rate and battery cooling time. The correspondence can be characterized by a function, which can be obtained by collecting the target openings associated with different basic openings, compound openings, opening adjustment rates and battery cooling time, and then using the above association to perform curve fitting.

[0048] For example, the corresponding relationship of the target opening degree at the current cooling moment can be calculated by the following formula:

[0049]

[0050] in, Indicates the target opening of the electronic expansion valve at the current cooling time. Indicates the basic opening of the electronic expansion valve at the current cooling time. Indicates the composite opening of the electronic expansion valve at the current cooling moment. Indicates the opening adjustment rate of the electronic expansion valve at the current cooling time, and Indicates the battery cooling time.

[0051] In the above-mentioned electronic expansion valve control method, the target opening of the electronic expansion valve at the current cooling moment is obtained according to the basic opening, compound opening, opening adjustment rate and battery cooling time; the target opening is used to control the opening of the electronic expansion valve at the current cooling moment to be adjusted to the target opening. The present application can control the opening of the electronic expansion valve of the target vehicle after the target vehicle enters the battery cooling mode, wherein the control method is to collect the ambient temperature, vehicle speed and battery cooling time of the target vehicle at the current moment, thereby obtaining the basic opening and compound opening of the electronic expansion valve at the current moment through the ambient temperature and vehicle speed, and obtaining the opening adjustment rate of the electronic expansion valve at the current moment through the vehicle speed, so that the basic opening, compound opening, opening adjustment rate and battery cooling time at the current moment can be used to obtain the target opening to control the electronic expansion valve. The control method does not need to use the superheat combined with PI algorithm to realize the opening adjustment of the electronic expansion valve, so the delay of the opening adjustment of the electronic expansion valve can be reduced.

[0052] In one embodiment, Figure 2 As shown, step S102 may further include:

[0053] Step S201, obtaining the basic opening adjustment rate of the electronic expansion valve at the current cooling moment according to the vehicle speed information.

[0054] Among them, the basic opening adjustment rate refers to the reference opening adjustment rate, which is directly related to the vehicle speed. Specifically, after obtaining the vehicle speed information at the current cooling moment, the controller can use the vehicle speed information to obtain the basic opening adjustment rate at the current cooling moment. For example, the basic opening adjustment rate can be obtained by calculating the formula using the vehicle speed information, or by looking up a table to obtain the basic opening adjustment rate.

[0055] Step S202, obtaining a first correction coefficient and a second correction coefficient for correcting a basic opening adjustment rate at the current cooling moment;

[0056] Step S203: using the first correction coefficient and the second correction coefficient, correct the basic opening adjustment rate to obtain the opening adjustment rate.

[0057] The first correction coefficient and the second correction coefficient refer to two different correction coefficients used to correct the basic opening adjustment rate. The controller can also obtain the first correction coefficient and the second correction coefficient, so as to use the first correction coefficient and the second correction coefficient to correct the basic opening adjustment rate to obtain the final opening adjustment rate at the current cooling moment. The first correction coefficient and the second correction coefficient can be determined based on certain real-time information of the target vehicle at the current cooling moment. Among them, the calculation of the opening adjustment rate can be obtained based on the correspondence between the pre-constructed basic opening adjustment rate and the first correction coefficient and the second correction coefficient. The correspondence can also be represented by a function. The function can be obtained by pre-collecting the opening adjustment rates associated with different basic opening adjustment rates, the first correction coefficient and the second correction coefficient, and then using the above-mentioned relationship to perform curve fitting.

[0058] For example, the corresponding relationship of the opening adjustment rate of the electronic expansion valve at the current cooling moment can be calculated by the following formula:

[0059]

[0060] in, Indicates the opening adjustment rate of the electronic expansion valve at the current cooling moment. Indicates the basic opening adjustment rate of the electronic expansion valve at the current cooling moment. represents the first correction coefficient, It represents the second correction coefficient.

[0061] In this embodiment, after obtaining the basic opening adjustment rate using the vehicle speed information, the basic opening adjustment rate can be further corrected using the first correction coefficient and the second correction coefficient. In this way, the accuracy of obtaining the basic opening adjustment rate can be further improved.

[0062] Furthermore, if Figure 3 As shown, step S202 may further include:

[0063] Step S301, obtain the refrigeration control cycle in which the current refrigeration moment is located, and obtain the current current fluctuation information and the current vehicle speed fluctuation information of the refrigeration control cycle; the current current fluctuation information is used to characterize the fluctuation of the battery current of the target vehicle in the refrigeration control cycle, and the current vehicle speed fluctuation information is used to characterize the fluctuation of the vehicle speed of the target vehicle in the refrigeration control cycle.

[0064] The cooling control cycle refers to the control cycle in which the current cooling moment is located. After the target vehicle enters the battery cooling mode, the cooling control cycle can be divided according to a preset time interval. For example, the time interval can be set to 3s. If the current cooling moment is the 5th second after entering the cooling mode, the cooling control cycle in which the current cooling moment is located is the second cooling control cycle. The current current fluctuation information can be used to characterize the fluctuation of the battery current of the target vehicle in the cooling control cycle, which can be characterized according to the difference between the maximum and minimum current values ​​of the cooling control cycle, while the current vehicle speed fluctuation information is used to characterize the fluctuation of the vehicle speed of the target vehicle in the cooling control cycle, which can be characterized according to the difference between the maximum and minimum vehicle speed values ​​of the cooling control cycle.

[0065] Specifically, the controller can identify the refrigeration control cycle in which the current refrigeration moment is located, and further obtain the current fluctuation information and the vehicle speed fluctuation information of the refrigeration control cycle as the current current fluctuation information and the current vehicle speed fluctuation information.

[0066] For example, the current fluctuation information can be calculated by the following formula:

[0067]

[0068] in, and is the maximum and minimum current value in the refrigeration control cycle at the current refrigeration moment. Indicates the current fluctuation information.

[0069] The current vehicle speed fluctuation information can be calculated using the following formula:

[0070]

[0071] in, and is the maximum and minimum vehicle speed in the cooling control cycle at the current cooling moment. Indicates the current vehicle speed fluctuation information.

[0072] Step S302, obtaining a pre-constructed first calibration relationship; the first calibration relationship stores the correspondence between different current fluctuation information and vehicle speed fluctuation information and different first correction coefficients; wherein the first correction coefficient is negatively correlated with the current fluctuation information and the vehicle speed fluctuation information.

[0073] The first calibration relationship refers to the correspondence between different current fluctuation information and vehicle speed fluctuation information and different first correction coefficients. The calibration relationship can be a correspondence table. The data in the table can be pre-calibrated, and the first correction coefficient is negatively correlated with the current fluctuation information and the vehicle speed fluctuation information. That is, the larger the current fluctuation information, the smaller the first correction coefficient. At the same time, the larger the vehicle speed fluctuation information, the smaller the first correction coefficient.

[0074] The first calibration relationship can be obtained by the following method: first, the vehicle is driven at a constant speed on the actual road and enters the battery cooling mode. By setting the basic opening and the compound opening, the vehicle speed is kept at 10, 20...80 within 3 minutes, and the battery temperature performance and current fluctuation are observed at this time. The first correction coefficient is corrected. If the battery temperature remains stable or decreases over a period of time (10-20 minutes), the first correction coefficient is recorded at this time. For example, the first calibration relationship can be shown in Table 1:

[0075] Table 1 The first calibration relationship table

[0076]

[0077] Step S303: Using the correction coefficient corresponding to the current current fluctuation information and the current vehicle speed fluctuation information in the first calibration relationship as the first correction coefficient for correcting the basic opening adjustment rate at the current cooling moment.

[0078] After obtaining the first calibration relationship, the correction coefficient corresponding to the current current fluctuation information and the current vehicle speed fluctuation information recorded in the first calibration relationship can be used as the first correction coefficient for correcting the basic opening adjustment rate at the current cooling moment. For example, when the current current fluctuation information is 10A and the current vehicle speed fluctuation information is 10km / h, the corresponding first correction coefficient is 0.6. Then the first correction coefficient for correcting the basic opening adjustment rate at the current cooling moment is 0.6.

[0079] In this embodiment, the first correction coefficient for correcting the basic opening adjustment rate can be obtained by using the current fluctuation information and the vehicle speed fluctuation information of the refrigeration control cycle at the current refrigeration moment, combined with a pre-constructed first calibration relationship. In this way, the accuracy and efficiency of obtaining the first correction coefficient can be improved.

[0080] In addition, if Figure 4 As shown, step S202 may further include:

[0081] Step S401, obtaining the current battery current value of the target vehicle at the current cooling moment and a pre-constructed second calibration relationship; the second calibration relationship stores the correspondence between different battery current values ​​and different current calibration parameters; wherein the current calibration parameter is positively correlated with the battery current value.

[0082] The current calibration parameter is a calibration parameter used to convert the battery current value into the second correction coefficient. In this embodiment, the second correction coefficient can be a correction parameter used to correct the current. When the vehicle is traveling at high speed, the motor load increases and a greater power output is required. At this time, the overall current level is higher and the current changes slowly and is relatively stable. Therefore, it is necessary to introduce a second correction coefficient for correction. The current battery current value refers to the current of the battery of the target vehicle at the current cooling moment.

[0083] The second calibration relationship refers to the correspondence between different battery current values ​​and different current calibration parameters. The calibration relationship can be a correspondence table. The data in the table can be pre-calibrated, and the current calibration parameter is positively correlated with the battery current value, that is, the larger the battery current, the larger the current calibration parameter. The second calibration relationship can be determined by the following principles: 1. If the battery cooling rate effect is not up to standard, appropriately increase the size of each second correction coefficient; 2. Appropriately control the product of the second calibration coefficient and the battery current value to ensure that the product is not too large, that is, the product ≤ 20; 3. The product of the second calibration coefficient and the battery current value can increase accordingly as the battery current value increases.

[0084] For example, the second calibration relationship may be as shown in Table 2:

[0085] Table 2 Second calibration relationship table

[0086]

[0087] Specifically, the controller may also obtain the battery current value of the target vehicle at the current cooling moment, and a pre-constructed second calibration relationship stored in the controller for characterizing the correspondence between different battery current values ​​and different current calibration parameters.

[0088] Step S402: acquiring a current current calibration parameter corresponding to the current battery current value from the second calibration relationship.

[0089] The current current calibration parameter refers to the current calibration parameter corresponding to the current battery current value recorded in the second calibration relationship. For example, as shown in Table 2, if the current battery current value is 50A, the current calibration parameter is 0.02. The controller can obtain the current calibration parameter corresponding to the current battery current value from the second calibration relationship as the current current calibration parameter.

[0090] Step S403, obtaining a second correction coefficient for correcting the basic opening adjustment rate at the current cooling moment according to the current battery current value and the current current calibration parameter.

[0091] After obtaining the current battery current value and the current current calibration parameter, the current battery current value and the current current calibration parameter can be used to calculate the second correction coefficient for correcting the basic opening adjustment rate at the current cooling moment. For example, the second correction coefficient can be calculated by the following formula:

[0092]

[0093] in, is the absolute value of the current battery current, that is, the current battery current value, Calibrate the parameters for the current.

[0094] In this embodiment, the second correction coefficient can be calculated by the current battery current value and the current current calibration parameter, wherein the current current calibration parameter can be obtained by a pre-constructed second calibration relationship, thereby improving the accuracy and efficiency of obtaining the second correction coefficient.

[0095] Furthermore, before step S402, the method may further include: when the current battery current value does not reach the minimum battery current value stored in the second calibration relationship, updating the current battery current value to the minimum battery current value.

[0096] The minimum battery current value refers to the minimum value of multiple different battery current values ​​stored in the second calibration relationship. Taking Table 2 as an example, the minimum battery current value is 50A. In order to avoid the situation where the current of the vehicle is small and the calculation of the second correction coefficient is too small, if the current battery current value does not reach the minimum battery current value, that is, it does not reach 50A, the current battery current value is updated to the above minimum battery current value, and then the updated current battery current value is used to calculate the second correction coefficient. For example, the current battery current value is 20A, which is less than the minimum battery current value of 50A. In this case, the minimum battery current value, that is, 50A, is used for calculation by default.

[0097] In this embodiment, if the current battery current value does not reach the minimum battery current value stored in the second calibration relationship, the current battery current value is updated to the minimum battery current value, so that the second correction coefficient is calculated using the minimum battery current value. This method can avoid the calculated second correction coefficient being too small, thereby further improving the accuracy of obtaining the second correction coefficient.

[0098] In one embodiment, step S201 may further include: obtaining a pre-constructed third calibration relationship; the third calibration relationship stores the corresponding relationship between different vehicle speed ranges and different basic opening adjustment rates; wherein, the basic opening adjustment rate is positively correlated with the vehicle speed range; obtaining the target vehicle speed range where the vehicle speed information is located, and using the basic opening adjustment rate corresponding to the target vehicle speed range in the third calibration relationship as the basic opening adjustment rate at the current refrigeration moment.

[0099] The third calibration relationship refers to the corresponding relationship used to store different vehicle speed ranges and different basic opening adjustment rates. This calibration relationship can also be a certain corresponding relationship table, and the data in the table can be pre-calibrated. Moreover, the basic opening adjustment rate is positively correlated with the vehicle speed range, that is, the greater the vehicle speed corresponding to the vehicle speed range, the greater the basic opening adjustment rate. This calibration relationship can be determined in the following way. The selection of the basic opening adjustment rate should first be based on the target vehicle model and battery model. If the target vehicle is relatively large as a whole and the maximum heat generation of the battery pack is relatively high, a larger basic opening adjustment rate is used. In addition, the adjustment rate also needs to be re-calibrated and confirmed by the calibration personnel based on the overall temperature performance and cooling effect of the battery during the actual vehicle driving process (low speed, medium speed, high speed).

[0100] For example, the third calibration relationship can be as shown in Table 3:

[0101] Table 3 Third Calibration Relationship Table

[0102]

[0103] Specifically, after the controller obtains the vehicle speed information of the target vehicle at the current refrigeration moment, it can first obtain the pre-constructed third calibration relationship, and obtain the vehicle speed range where the vehicle speed information is located as the target vehicle speed range from the multiple vehicle speed ranges included in the third calibration relationship. For example, if the vehicle speed is 50 km / h, then the target vehicle speed range is the range of 40 < V < 80, and the corresponding basic opening adjustment rate of 5 in this range is used as the basic opening adjustment rate at the current refrigeration moment.

[0104] In this embodiment, the target vehicle speed range where the vehicle speed information is located can also be identified by pre-constructing the third calibration relationship, so as to use the basic opening adjustment rate corresponding to the target vehicle speed range as the basic opening adjustment rate at the current refrigeration moment. By this method, the acquisition efficiency of the basic opening adjustment rate at the current refrigeration moment can be improved.

[0105] In one embodiment, step S102 may further include: obtaining a pre-constructed fourth calibration relationship; the fourth calibration relationship stores the correspondence between different ambient temperatures and vehicle speed information and different basic openings; and using the basic opening corresponding to the ambient temperature and vehicle speed information at the current cooling moment in the fourth calibration relationship as the basic opening of the electronic expansion valve at the current cooling moment.

[0106] The fourth calibration relationship is used to store the corresponding relationship between different ambient temperatures and vehicle speed information and different basic openings, and the calibration relationship can be stored in a table. In addition, the calibration relationship can be obtained by driving the vehicle at a constant speed in the environmental chamber to ensure that the heating power of the battery is relatively stable, and then starting the battery cooling for 10 minutes. If the average temperature of the battery cell remains stable without an upward or downward trend, the current opening of the electronic expansion valve is recorded. In this embodiment, the basic opening can be obtained by querying the calibration relationship table, that is, the basic opening corresponding to the ambient temperature and vehicle speed information at the current cooling moment stored in the fourth calibration relationship is used as the basic opening of the electronic expansion valve at the current cooling moment.

[0107] For example, the fourth calibration relationship may be shown in Table 4:

[0108] Table 4 Fourth calibration relationship table

[0109]

[0110] It can be seen that if the ambient temperature during the current cooling period is 10°C and the vehicle speed is 30 km / h, the basic opening degree is 20, and if the ambient temperature during the current cooling period is 10°C and the vehicle speed is 40 km / h, the basic opening degree is 30, and so on.

[0111] In this embodiment, the fourth calibration relationship may be pre-set to obtain the basic opening at the current cooling moment corresponding to the ambient temperature and vehicle speed information at the current cooling moment. This method can improve the efficiency of obtaining the basic opening.

[0112] In one embodiment, step S102 may also include: obtaining a pre-constructed fifth calibration relationship; the fifth calibration relationship stores the correspondence between different ambient temperatures and vehicle speed information and different compound openings; and using the compound opening corresponding to the ambient temperature and vehicle speed information at the current cooling moment in the fifth calibration relationship as the compound opening of the electronic expansion valve at the current cooling moment.

[0113] The fifth calibration relationship is used to store the corresponding relationship between different ambient temperatures and vehicle speed information and different composite openings. Similar to the fourth calibration relationship, this calibration relationship can be stored in a table. In addition, the calibration of this calibration relationship can be carried out in an environmental chamber. Given a constant vehicle speed and temperature, after the battery is heated to a certain temperature, the battery cooling is turned on. At this time, if the total opening of the composite opening and the basic opening can make the battery cool down from entry to exit in about 30 minutes (this time needs to be experimentally determined on the battery cold plate), the composite opening is recorded. In this embodiment, the composite opening can be obtained by querying the calibration relationship table, that is, the composite opening corresponding to the ambient temperature and vehicle speed information at the current cooling moment stored in the fifth calibration relationship is used as the composite opening of the electronic expansion valve at the current cooling moment.

[0114] For example, the fifth calibration relationship may be shown in Table 5:

[0115] Table 5 Fifth calibration relationship table

[0116]

[0117] It can be seen that if the ambient temperature during the current cooling period is 10°C and the vehicle speed is 30 km / h, the compound opening is 40, and if the ambient temperature during the current cooling period is 10°C and the vehicle speed is 40 km / h, the compound opening is 30, and so on.

[0118] In this embodiment, the fifth calibration relationship may be pre-set to obtain the composite opening at the current cooling moment corresponding to the ambient temperature and vehicle speed information at the current cooling moment. This method can improve the efficiency of obtaining the composite opening.

[0119] In one embodiment, Figure 5 As shown, step S103 may further include:

[0120] Step S501, obtaining the refrigeration working mode of the target vehicle at the current refrigeration moment, and obtaining the temperature difference information of the evaporator of the target vehicle at the current refrigeration moment; the temperature difference information represents the difference between the actual temperature of the evaporator at the current refrigeration moment and the target temperature; the evaporator is used to adjust the temperature of the passenger compartment of the target vehicle.

[0121] The evaporator refers to a component of the air conditioning system of the target vehicle, and its main function is to achieve cooling through heat exchange to adjust the temperature of the passenger compartment of the target vehicle, while the temperature difference information refers to the temperature difference between the actual temperature of the evaporator at the current cooling moment and the target temperature to be adjusted, and the cooling working mode is used to represent the working mode of the target vehicle for battery cooling. In this embodiment, the target vehicle may also need to cool the passenger compartment during the process of cooling the vehicle battery. If the opening of the electronic expansion valve used to control the cooling process of the vehicle battery is too large, it may cause uneven distribution of the refrigerant flow, thereby failing to meet the cooling needs of the passenger compartment. Therefore, in this embodiment, the cooling working mode of the target vehicle at the current cooling moment also needs to be considered to finally determine the target opening.

[0122] Specifically, when the controller obtains the target opening of the electronic expansion valve at the current cooling moment, it first needs to obtain the cooling working mode of the target vehicle at the current cooling moment, and obtain the temperature difference information of the evaporator of the vehicle at the current cooling moment.

[0123] Step S502, according to the cooling working mode, obtain the passenger compartment comfort compensation coefficient pre-set for the passenger compartment, and use the passenger compartment comfort compensation coefficient and temperature difference information to obtain the opening loss of the electronic expansion valve at the current cooling moment.

[0124] The opening loss refers to the reduction in the opening of the electronic expansion valve at the current cooling moment due to the demand for passenger compartment cooling. This loss is used to avoid the situation where the electronic expansion valve is too open, resulting in uneven refrigerant flow distribution and failure to meet the passenger compartment cooling demand. The loss can be obtained based on the passenger compartment comfort compensation coefficient and temperature difference information, where the passenger compartment comfort compensation coefficient is related to the refrigeration working mode. The passenger compartment comfort compensation coefficient may be different for different refrigeration working modes.

[0125] Specifically, after obtaining the refrigeration working mode, the controller can obtain the passenger compartment comfort compensation coefficient corresponding to the refrigeration working mode, which is pre-set for the passenger compartment of the target vehicle. Then, the passenger compartment comfort compensation coefficient and the temperature difference information obtained in step S501 can be used to calculate the opening loss of the electronic expansion valve at the current refrigeration moment.

[0126] Step S503, obtaining a target opening according to the basic opening, the compound opening, the opening adjustment rate, the battery cooling time and the opening loss.

[0127] Finally, the controller can calculate the target opening according to the basic opening, compound opening, opening adjustment rate, battery cooling time, and opening loss. For example, the target opening can be calculated by the following formula:

[0128]

[0129] in, Indicates the target opening of the electronic expansion valve at the current cooling time. Indicates the basic opening of the electronic expansion valve at the current cooling time. Indicates the composite opening of the electronic expansion valve at the current cooling moment. Indicates the opening adjustment rate of the electronic expansion valve at the current cooling moment. Indicates the battery cooling time, and Indicates the opening loss at the current cooling moment. represents the passenger compartment comfort compensation coefficient in the cooling working mode at the current cooling moment, and Indicates the temperature difference information of the evaporator at the current cooling moment.

[0130] In this embodiment, the comfort compensation coefficient of the passenger compartment can also be obtained based on the refrigeration working mode of the target vehicle at the current refrigeration moment and the temperature difference of the evaporator of the target vehicle at the current refrigeration moment, so as to calculate the opening loss using the comfort compensation coefficient of the passenger compartment and the temperature difference, and then combine the basic opening, compound opening, opening adjustment rate, battery cooling time and opening loss to obtain the target opening. In this way, during the cooling process of the vehicle battery, the uneven distribution of refrigerant flow can be avoided, which leads to the failure to meet the cooling needs of the passenger compartment, thereby further improving the accuracy of the target opening setting.

[0131] Furthermore, the refrigeration working mode includes: a first working mode for characterizing that the passenger compartment is cooled preferentially, a second working mode for cooling the battery of the target vehicle preferentially, and a third working mode for cooling only the battery; step S502 may further include: when the refrigeration working mode is the first working mode, the passenger compartment comfort compensation coefficient is set to the first compensation coefficient; when the refrigeration working mode is the second working mode, the passenger compartment comfort compensation coefficient is set to the second compensation coefficient; wherein the second compensation coefficient is less than the first compensation coefficient; when the refrigeration working mode is the third working mode, the passenger compartment comfort compensation coefficient is set to zero.

[0132] In this embodiment, the cooling working mode for cooling the battery may include the following three working modes, namely, a first working mode for cooling the passenger compartment first, a second working mode for cooling the battery first, and a third working mode for cooling the battery only without cooling the passenger compartment. In the three working modes, the comfort compensation coefficients for the passenger compartment are also different. If the first working mode for cooling the passenger compartment first is used, the first compensation coefficient is used, and if the second working mode for cooling the battery first is used, the second compensation coefficient is used.

[0133] And according to the formula: It can be seen that the passenger compartment comfort compensation coefficient is negatively correlated with the target opening. In the first working mode, since the passenger compartment needs to be cooled first, the opening of the electronic expansion valve needs to be reduced to a greater extent, so a larger passenger compartment comfort compensation coefficient is used. In the second working mode, since the battery needs to be cooled first, the opening of the electronic expansion valve can only be reduced to a smaller extent, so a smaller passenger compartment comfort compensation coefficient is used. Therefore, the second compensation coefficient is smaller than the first compensation coefficient.

[0134] If the cooling working mode is the third working mode for cooling only the battery, that is, there is no need to cool the passenger compartment, the passenger compartment comfort compensation coefficient can be directly set to zero.

[0135] In this embodiment, the refrigeration working mode may include a first working mode for giving priority to cooling the passenger compartment, a second working mode for giving priority to cooling the battery of the target vehicle, and a third working mode for cooling only the battery, so that the corresponding passenger compartment comfort compensation coefficient can be set according to different working modes. In this way, the intelligence level of setting the passenger compartment comfort compensation coefficient can be further improved.

[0136] In addition, step S501 may further include: when there is a cooling demand in the passenger compartment and the battery cell temperature of the target vehicle exceeds the first temperature threshold but does not exceed the second temperature threshold, determining that the cooling operating mode is the first operating mode; the second temperature threshold is greater than the first temperature threshold; when there is a cooling demand in the passenger compartment and the battery cell temperature exceeds the second temperature threshold but does not exceed the third temperature threshold, determining that the cooling operating mode is the second operating mode; the third temperature threshold is greater than the second temperature threshold; when the battery cell temperature exceeds the third temperature threshold, or when there is no cooling demand in the passenger compartment and the battery cell temperature exceeds the first temperature threshold, determining that the cooling operating mode is the third operating mode.

[0137] Among them, the first temperature threshold is the temperature threshold for starting the battery cooling process, the second temperature threshold is the temperature threshold for giving priority to battery cooling, and the third temperature threshold is the battery limit threshold temperature. It can be seen that the first temperature threshold is smaller than the second temperature threshold, and the second temperature threshold is smaller than the third temperature threshold. Therefore, the controller can determine which specific cooling mode to use based on the relationship between the battery cell temperature of the target vehicle at the current cooling moment and the above temperature thresholds.

[0138] Specifically, the controller can first determine whether the current battery cell temperature exceeds the first temperature threshold. If it exceeds, it means that the battery needs to be cooled, thereby entering the selection of the cooling working mode. The controller can then determine whether there is a cooling demand for the current passenger compartment. If there is no cooling demand for the current passenger compartment, the default cooling working mode is the third working mode. If there is a cooling demand for the current passenger compartment, it is determined whether the current battery cell temperature exceeds the second temperature threshold. If it does not exceed, the first working mode of cooling the passenger compartment first is adopted. If it exceeds the second temperature threshold, it is determined whether it exceeds the third temperature threshold. If it does not exceed, the second working mode of cooling the battery of the target vehicle first can be adopted. If it exceeds the third temperature threshold, that is, the battery limit threshold temperature has been exceeded, even if there is a cooling demand for the passenger compartment, it is necessary to stop the cooling of the passenger compartment, that is, set the third working mode of cooling only the battery.

[0139] In this embodiment, the cooling working mode to be used can also be determined based on the battery cell temperature of the target vehicle and whether there is a cooling demand in the passenger compartment. In this way, the accuracy of the cooling working mode setting can be improved.

[0140] In one embodiment, a method for controlling an electronic expansion valve in a battery passenger compartment of an electric vehicle with single or double cooling is also provided. The method can be based on a comprehensive optimization algorithm for vehicle speed, current size, ambient temperature, battery cooling time, and passenger compartment comfort, etc., and can effectively ensure battery cooling and reasonable distribution of refrigerant flow between the battery and passenger compartment while achieving a dynamic adaptive effect of opening adjustment, effectively improving the delay of the existing EXV opening PI adjustment algorithm. The specific process is as follows:

[0141] First, obtain the preset battery cooling temperature threshold , prioritize the temperature threshold for battery cooling , battery limit threshold temperature and < < When the battery temperature reaches the battery cooling threshold If the battery temperature continues to rise and reaches the temperature threshold where battery cooling is prioritized, the vehicle battery will need to be cooled. If the passenger compartment cooling is turned on at the same time, it is necessary to switch to the working mode that prioritizes battery cooling. If the battery temperature continues to rise and reaches the battery limit threshold temperature , then you need to turn off the passenger compartment cooling to ensure that all the refrigerant is used for battery cooling. When cooling a single battery, the maximum temperature T of the battery cell exceeds the threshold and less than When setting the basic opening size of EXV to This parameter only needs to meet the most basic cooling requirements of the battery under different ambient temperatures. Please refer to Table 4.

[0142] Table 4 It is obtained through actual calibration work and only meets the most basic cooling needs of the battery. Since the battery heat generation and cooling effect are different under different ambient temperatures, the current opening of the electronic expansion valve can be recorded when the average temperature of the battery cell remains stable without rising or falling after a constant heating power is given to the battery in the environmental chamber and the battery cooling is turned on for 10 minutes. In addition, since the heating power of the battery directly affects the cooling effect, it is recommended to take the heating power value of the battery as a reference to the conditions when driving at different constant vehicle speeds.

[0143] When the vehicle is running fast or the ambient temperature is high, the battery generates a lot of heat. It cannot meet the battery cooling demand, and the common PI control method of adjusting the opening is calculated based on the superheat on the battery side. Since the cooling has just begun, the three heat exchange pathways in the entire cooling system, namely the battery and cold plate, the cold plate and the refrigerant, and the refrigerant and the external environment, all require a lot of time to move heat. Therefore, the superheat is usually not guaranteed to be controlled to the target superheat range (taking 5°C as an example) during the initial cooling. It takes a long time to adjust the opening before the overheat can be stabilized, resulting in a very delayed adjustment process. Therefore, it is proposed here to directly adjust the opening of the EXV based on the cooling time of the battery, and to link the opening size with the cooling time to obtain the opening size of the EXV. The calculation formula is as follows:

[0144]

[0145] Among them, t is the time to enter the battery cooling, in seconds; is the composite opening of the electronic expansion valve, and n is the adjustment rate of the expansion valve opening. similar, It also needs to be calibrated, and its size should fully meet the cooling requirements of the battery, taking Table 5 as an example.

[0146] To better display the function Here we take n=5 as an example. Figure 6 As shown in Figure 2, as the battery enters cooling time, the function The value of is getting larger and closer to 1, so this function can make the EXV opening adjustment have an upper limit, so as to avoid excessive refrigerant flow entering, resulting in waste of cooling capacity or affecting the comfort of the passenger compartment. In addition, if the value of n is larger, the function Therefore, the adjustment rate n should be directly related to the heat generation of the battery, ignoring a series of complex and lagging processes such as intermediate heat exchange, and directly achieving the purpose of quickly adjusting the opening based on the temperature change trend of the battery itself.

[0147] In the calculation of heat generation, it is usually assumed that the heat generation of the battery pack is evenly distributed inside, and the heat generation of the battery is divided into two parts: irreversible Joule heat and reversible reaction heat. When calculating the total heat generation of the battery, the lithium-ion battery heat generation model proposed by Bernaridi is used, in which the heat generation rate of the battery is expressed as q as follows:

[0148]

[0149] in, is the volume of the single cell, in m 3 ; I is the current, the unit is A; is the open circuit voltage, unit is V; U is the operating voltage, unit is V; T is the temperature, unit is K.

[0150] From the above formula, we can see that the heat generation rate q of the battery is directly related to the current charge and discharge current I of the battery. That is, the greater the current, the greater the heat generation rate, which ultimately leads to greater heat generation. For battery AC and DC charging, the current is relatively stable and will not fluctuate significantly in a short period of time. However, under battery discharge conditions such as vehicle driving or using air conditioning, the current will fluctuate greatly by tens or hundreds of amperes in a short period of time due to the influence of vehicle speed, high-voltage accessories, road conditions, and energy recovery, causing its heat generation rate to fluctuate significantly in a short period of time. Therefore, it is inevitable that a large error will be caused if the opening of the EXV is evaluated only from the current size. Therefore, the adjustment rate n is corrected again to the following formula:

[0151]

[0152] in, As the basic adjustment rate, is the working condition correction factor, is the current correction factor.

[0153] First, adjust the rate for the base , when evaluating the energy efficiency of electric vehicles, since vehicle speed is one of the key factors affecting battery power consumption, the energy consumption difference is significant at different vehicle speeds and directly affects the current magnitude. Therefore, based on the vehicle speed, the vehicle driving conditions can be roughly divided into three cases: 1. Low-speed driving (V ≤ 40 km / h), which is usually reflected in congested sections of urban traffic or frequent stops and starts. 2. Medium-speed driving (40 < V < 80 km / h), which is the common speed range of most urban expressways and some highways. 3. High-speed driving (V ≥ 80 km / h), when the vehicle enters the highway and travels at a high speed, the energy consumption will increase significantly. At this time, the basic adjustment rate The selection can be as shown in Table 3.

[0154] Considering the low-speed driving situation, the overall current magnitude is small, but the frequent acceleration and deceleration enable the regenerative braking system to effectively recover energy, and at the same time, it also causes large fluctuations in the current; during medium-speed driving, compared with low-speed driving, the regenerative braking opportunities decrease, and it is relatively stable overall, but there is still a certain amount of energy recovery. To sum up, considering that the vehicle condition changes in real time, in order to reflect the overall change trend, current fluctuation and vehicle speed fluctuation are introduced here, and their definitions are as follows:

[0155]

[0156]

[0157] Among them, and are the maximum and minimum values of the current within a cycle (3 s), and the unit is A; and are the maximum and minimum values of the vehicle speed within a cycle, and the unit is km / h. Then, the correction coefficient is used to correct the three driving conditions, and the look-up table is shown in Table 1.

[0158] Then, considering that when the vehicle is driving at a high speed, the motor load increases and a larger power output is required. At this time, the overall current magnitude is relatively high, and the change of the current is slow and relatively stable. Therefore, the current correction parameter is introduced, and its calculation formula is as follows:

[0159]

[0160] Among them, is the absolute value of the current, is the current calibration parameter, and the look-up table is shown in Table 2.

[0161] To avoid the influence of small current when the vehicle is stationary on the calculation of the correction parameter If the absolute value of the current is less than 50, the default value is Calculate the rest according to the above formula Look up Table 2 for calculation.

[0162] In summary, the final opening size of EXV for single cooling is The calculation formula is:

[0163]

[0164] After the introduction of passenger compartment cooling, the single cooling is converted to dual cooling. In order to ensure the cooling of the passenger compartment and the battery at the same time, the calculation formula for battery single cooling is finally converted to:

[0165]

[0166] in, To compensate for the comfort of the passenger compartment, The larger it is, the less refrigerant is allocated to the battery side. It is divided into three types according to the actual calibration situation, with the crew compartment taking priority. , Battery Priority and battery cooling only ,in , ; is the temperature difference between the current actual evaporator temperature and the target temperature. The execution logic of the single and double cooling priority of the passenger compartment can be as follows Figure 7 shown.

[0167] In summary, the calculation logic of the EXV opening algorithm provided in this embodiment is as follows:

[0168] 1. The controller reads the current vehicle speed V and the absolute value of the current , Current fluctuation within one cycle (3s) Speed ​​fluctuation And the current maximum temperature T of the battery cell and the external environment temperature Ta;

[0169] 2. Determine the current priority of single and double cooling and calculate the basic opening by looking up the table respectively , composite opening , basic adjustment rate , working condition correction factor And current calibration parameters and passenger compartment comfort compensation ;

[0170] 3. Read the time when the battery enters cooling mode and calculate the current opening size of EXV;

[0171] 4. Repeat the above steps to complete the EXV opening control under different working conditions until the battery cools down and exits.

[0172] Through this embodiment, when the battery is cooled, adaptive dynamic adjustment can be achieved comprehensively based on vehicle speed, current size, ambient temperature, passenger compartment comfort and other aspects, thereby improving the delay of the traditional algorithm for adjusting the EXV opening based on overheat PI, and directly adjusting the opening according to the vehicle condition. When the battery is cooled, different passenger compartment and battery cooling effects and flow distribution can be met according to the vehicle model calibration.

[0173] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0174] Based on the same inventive concept, the embodiment of the present application also provides an electronic expansion valve control device for implementing the electronic expansion valve control method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more electronic expansion valve control device embodiments provided below can refer to the limitations of the electronic expansion valve control method above, and will not be repeated here.

[0175] In one embodiment, Figure 8 As shown, an electronic expansion valve control device is provided, including: a vehicle information acquisition module 801, an adjustment information acquisition module 802 and a target opening acquisition module 803, wherein:

[0176] The vehicle information acquisition module 801 is used to obtain the ambient temperature and vehicle speed information of the target vehicle at the current cooling time, and obtain the battery cooling time of the target vehicle; the battery cooling time is the time from the battery starting cooling time of the target vehicle to the current cooling time;

[0177] The adjustment information acquisition module 802 is used to obtain the basic opening and compound opening of the electronic expansion valve of the target vehicle at the current cooling moment according to the ambient temperature and vehicle speed information, and to obtain the opening adjustment rate of the electronic expansion valve at the current cooling moment according to the vehicle speed information;

[0178] The target opening acquisition module 803 is used to obtain the target opening of the electronic expansion valve at the current cooling moment according to the basic opening, the compound opening, the opening adjustment rate and the battery cooling time; the target opening is used to control the opening of the electronic expansion valve at the current cooling moment to be adjusted to the target opening.

[0179] In one embodiment, the adjustment information acquisition module 802 is further used to obtain the basic opening adjustment rate of the electronic expansion valve at the current refrigeration moment according to the vehicle speed information; obtain the first correction coefficient and the second correction coefficient used to correct the basic opening adjustment rate at the current refrigeration moment; use the first correction coefficient and the second correction coefficient to correct the basic opening adjustment rate to obtain the opening adjustment rate.

[0180] In one embodiment, the adjustment information acquisition module 802 is further used to obtain the refrigeration control cycle in which the current refrigeration moment is located, and obtain the current current fluctuation information and the current vehicle speed fluctuation information of the refrigeration control cycle; the current current fluctuation information is used to characterize the fluctuation of the battery current of the target vehicle in the refrigeration control cycle, and the current vehicle speed fluctuation information is used to characterize the fluctuation of the vehicle speed of the target vehicle in the refrigeration control cycle; obtain a pre-constructed first calibration relationship; the first calibration relationship stores the correspondence between different current fluctuation information and vehicle speed fluctuation information and different first correction coefficients; wherein, the first correction coefficient is negatively correlated with the current fluctuation information and the vehicle speed fluctuation information; the correction coefficient corresponding to the current current fluctuation information and the current vehicle speed fluctuation information in the first calibration relationship is used as the first correction coefficient for correcting the basic opening adjustment rate in the current refrigeration moment.

[0181] In one embodiment, the adjustment information acquisition module 802 is further used to obtain the current battery current value of the target vehicle at the current cooling moment, and a pre-constructed second calibration relationship; the second calibration relationship stores the correspondence between different battery current values ​​and different current calibration parameters; wherein the current calibration parameter is positively correlated with the battery current value; from the second calibration relationship, the current current calibration parameter corresponding to the current battery current value is obtained; according to the current battery current value and the current current calibration parameter, a second correction coefficient for correcting the basic opening adjustment rate at the current cooling moment is obtained.

[0182] In one embodiment, the adjustment information acquisition module 802 is further configured to update the current battery current value to the minimum battery current value when the current battery current value does not reach the minimum battery current value stored in the second calibration relationship.

[0183] In one embodiment, the adjustment information acquisition module 802 is further used to obtain a pre-constructed third calibration relationship; the third calibration relationship stores the correspondence between different vehicle speed ranges and different basic opening adjustment rates; wherein the basic opening adjustment rate is positively correlated with the vehicle speed range; the target vehicle speed range where the vehicle speed information is located is obtained, and the basic opening adjustment rate corresponding to the target vehicle speed range in the third calibration relationship is used as the basic opening adjustment rate at the current cooling moment.

[0184] In one embodiment, the adjustment information acquisition module 802 is further used to obtain a pre-constructed fourth calibration relationship; the fourth calibration relationship stores the correspondence between different ambient temperatures and vehicle speed information and different basic openings; the basic opening corresponding to the ambient temperature and vehicle speed information at the current cooling moment in the fourth calibration relationship is used as the basic opening of the electronic expansion valve at the current cooling moment.

[0185] In one embodiment, the adjustment information acquisition module 802 is also used to obtain a pre-constructed fifth calibration relationship; the fifth calibration relationship stores the correspondence between different ambient temperatures and vehicle speed information and different composite openings; the composite opening corresponding to the ambient temperature and vehicle speed information at the current cooling moment in the fifth calibration relationship is used as the composite opening of the electronic expansion valve at the current cooling moment.

[0186] In one embodiment, the target opening acquisition module 803 is further used to obtain the refrigeration working mode of the target vehicle at the current refrigeration moment, and obtain the temperature difference information of the evaporator of the target vehicle at the current refrigeration moment; the temperature difference information represents the difference between the actual temperature of the evaporator at the current refrigeration moment and the target temperature; the evaporator is used to adjust the temperature of the passenger compartment of the target vehicle; according to the refrigeration working mode, the passenger compartment comfort compensation coefficient pre-set for the passenger compartment is obtained, and the passenger compartment comfort compensation coefficient and the temperature difference information are used to obtain the opening loss of the electronic expansion valve at the current refrigeration moment; according to the basic opening, the composite opening, the opening adjustment rate, the battery cooling time and the opening loss, the target opening is obtained.

[0187] In one embodiment, the cooling working mode includes: a first working mode for characterizing that the passenger compartment is cooled preferentially, a second working mode for cooling the battery of the target vehicle preferentially, and a third working mode for cooling only the battery; the target opening acquisition module 803 is further used to set the passenger compartment comfort compensation coefficient to the first compensation coefficient when the cooling working mode is the first working mode; set the passenger compartment comfort compensation coefficient to the second compensation coefficient when the cooling working mode is the second working mode; wherein the second compensation coefficient is less than the first compensation coefficient; and set the passenger compartment comfort compensation coefficient to zero when the cooling working mode is the third working mode.

[0188] In one embodiment, the target opening acquisition module 803 is further used to determine that the refrigeration operating mode is the first operating mode when there is a cooling demand in the passenger compartment and the battery cell temperature of the target vehicle exceeds the first temperature threshold but does not exceed the second temperature threshold; the second temperature threshold is greater than the first temperature threshold; when there is a cooling demand in the passenger compartment and the battery cell temperature exceeds the second temperature threshold but does not exceed the third temperature threshold, the refrigeration operating mode is determined to be the second operating mode; the third temperature threshold is greater than the second temperature threshold; when the battery cell temperature exceeds the third temperature threshold, or when there is no cooling demand in the passenger compartment and the battery cell temperature exceeds the first temperature threshold, the refrigeration operating mode is determined to be the third operating mode.

[0189] Each module in the above electronic expansion valve control device can be implemented in whole or in part by software, hardware or a combination thereof. Each module can be embedded in or independent of the processor in the controller in the form of hardware, or can be stored in the memory in the controller in the form of software, so that the processor can call and execute the operations corresponding to each module.

[0190] In one embodiment, a controller is provided, whose internal structure diagram can be as follows: Fig. 9 As shown. The controller includes a processor, a memory, an input / output interface and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the controller is used to provide computing and control capabilities. The memory of the controller includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the controller is used to exchange information between the processor and an external device. The communication interface of the controller is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, near field communication (NFC) or other technologies. When the computer program is executed by the processor, an electronic expansion valve control method is implemented.

[0191] Those skilled in the art will understand that Fig. 9 The structure shown in the figure is merely a block diagram of a partial structure related to the scheme of the present application, and does not constitute a limitation on the controller to which the scheme of the present application is applied. The specific controller may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0192] In one embodiment, a controller is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0193] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0194] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0195] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0196] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0197] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0198] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the present application. It should be noted that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. An electronic expansion valve control method, characterized in that: The method comprises: Acquire the ambient temperature and vehicle speed information of the target vehicle at the current cooling time, and acquire the battery cooling time of the target vehicle; the battery cooling time is the time from the battery start cooling time of the target vehicle to the current cooling time; According to the ambient temperature and the vehicle speed information, obtaining the basic opening and the composite opening of the electronic expansion valve of the target vehicle at the current cooling moment, and according to the vehicle speed information, obtaining the opening adjustment rate of the electronic expansion valve at the current cooling moment; The target opening of the electronic expansion valve at the current cooling moment is obtained according to the basic opening, the compound opening, the opening adjustment rate and the battery cooling time; the target opening is used to control the opening of the electronic expansion valve at the current cooling moment to be adjusted to the target opening.

2. The method according to claim 1, characterized in that: The obtaining, according to the vehicle speed information, the opening adjustment rate of the electronic expansion valve at the current cooling moment includes: According to the vehicle speed information, obtaining a basic opening adjustment rate of the electronic expansion valve at the current cooling moment; Obtaining a first correction coefficient and a second correction coefficient for correcting the basic opening adjustment rate at the current refrigeration moment; The basic opening adjustment rate is corrected by using the first correction coefficient and the second correction coefficient to obtain the opening adjustment rate.

3. The method according to claim 2, characterized in that The first correction coefficient is obtained by the following steps: Acquire the refrigeration control cycle in which the current refrigeration moment is located, and acquire current current fluctuation information and current vehicle speed fluctuation information of the refrigeration control cycle; the current current fluctuation information is used to characterize the fluctuation of the battery current of the target vehicle in the refrigeration control cycle, and the current vehicle speed fluctuation information is used to characterize the fluctuation of the vehicle speed of the target vehicle in the refrigeration control cycle; Obtaining a pre-built first calibration relationship; The first calibration relationship stores the correspondence between different current fluctuation information and vehicle speed fluctuation information and different first correction coefficients; wherein the first correction coefficient is negatively correlated with the current fluctuation information and the vehicle speed fluctuation information; The correction coefficient corresponding to the current current fluctuation information and the current vehicle speed fluctuation information in the first calibration relationship is used as the first correction coefficient for correcting the basic opening adjustment rate in the current cooling moment.

4. The method according to claim 2, characterized in that: The second correction coefficient is obtained by the following steps: Acquire the current battery current value of the target vehicle at the current cooling moment and a pre-constructed second calibration relationship; the second calibration relationship stores a correspondence between different battery current values ​​and different current calibration parameters; wherein the current calibration parameter is positively correlated with the battery current value; Acquire a current current calibration parameter corresponding to the current battery current value from the second calibration relationship; According to the current battery current value and the current current calibration parameter, a second correction coefficient for correcting the basic opening adjustment rate at the current cooling moment is obtained.

5. The method according to claim 2, characterized in that: The obtaining, according to the vehicle speed information, a basic opening adjustment rate of the electronic expansion valve at the current cooling moment includes: Acquire a pre-constructed third calibration relationship; the third calibration relationship stores a correspondence between different vehicle speed intervals and different basic opening adjustment rates; wherein the basic opening adjustment rate is positively correlated with the vehicle speed interval; A target vehicle speed interval in which the vehicle speed information is located is obtained, and a basic opening adjustment rate corresponding to the target vehicle speed interval in the third calibration relationship is used as the basic opening adjustment rate at the current cooling moment.

6. The method according to claim 1, characterized in that The obtaining, according to the ambient temperature and the vehicle speed information, a basic opening degree of the electronic expansion valve of the target vehicle at the current cooling moment includes: Acquire a pre-constructed fourth calibration relationship; the fourth calibration relationship stores the correspondence between different ambient temperatures and vehicle speed information and different basic openings; The basic opening degree corresponding to the ambient temperature and vehicle speed information at the current cooling moment in the fourth calibration relationship is used as the basic opening degree of the electronic expansion valve at the current cooling moment.

7. The method according to claim 1, characterized in that The composite opening is obtained by the following steps: Acquire a pre-constructed fifth calibration relationship; the fifth calibration relationship stores the correspondence between different ambient temperatures and vehicle speed information and different composite openings; The composite opening degree corresponding to the ambient temperature and vehicle speed information at the current cooling moment in the fifth calibration relationship is used as the composite opening degree of the electronic expansion valve at the current cooling moment.

8. The method according to any one of claims 1 to 7, characterized in that: The acquiring, according to the basic opening, the compound opening, the opening adjustment rate and the battery cooling time, the target opening of the electronic expansion valve at the current cooling time comprises: Acquiring a refrigeration working mode of the target vehicle at a current refrigeration moment, and acquiring temperature difference information of an evaporator of the target vehicle at the current refrigeration moment; the temperature difference information represents a difference between an actual temperature of the evaporator at the current refrigeration moment and a target temperature; the evaporator is used to adjust the temperature of a passenger compartment of the target vehicle; According to the cooling working mode, obtaining a passenger compartment comfort compensation coefficient pre-set for the passenger compartment, and using the passenger compartment comfort compensation coefficient and the temperature difference information to obtain an opening loss of the electronic expansion valve at the current cooling moment; The target opening is obtained according to the basic opening, the composite opening, the opening adjustment rate, the battery cooling time and the opening loss.

9. The method according to claim 8, characterized in that The refrigeration working mode includes: a first working mode for indicating that the passenger compartment is refrigerated preferentially, a second working mode for refrigerating the battery of the target vehicle preferentially, and a third working mode for refrigerating only the battery; the obtaining of a passenger compartment comfort compensation coefficient pre-set for the passenger compartment according to the refrigeration working mode includes: When the cooling working mode is the first working mode, setting the passenger compartment comfort compensation coefficient to a first compensation coefficient; When the cooling working mode is the second working mode, the passenger compartment comfort compensation coefficient is set to a second compensation coefficient; wherein the second compensation coefficient is smaller than the first compensation coefficient; When the cooling working mode is the third working mode, the passenger compartment comfort compensation coefficient is set to zero.

10. The method according to claim 9, characterized in that The obtaining of the refrigeration working mode of the target vehicle at the current refrigeration moment includes: When there is a cooling demand in the passenger compartment and the battery cell temperature of the target vehicle exceeds a first temperature threshold but does not exceed a second temperature threshold, determining that the cooling working mode is the first working mode; and the second temperature threshold is greater than the first temperature threshold; When there is a cooling demand in the passenger compartment and the battery cell temperature exceeds the second temperature threshold but does not exceed the third temperature threshold, determining that the cooling working mode is the second working mode; the third temperature threshold is greater than the second temperature threshold; When the battery cell temperature exceeds the third temperature threshold, or when there is no cooling demand for the passenger compartment and the battery cell temperature exceeds the first temperature threshold, the cooling operation mode is determined to be the third operation mode.

11. An electronic expansion valve control device, characterized in that: The device comprises: A vehicle information acquisition module is used to acquire the ambient temperature and vehicle speed information of the target vehicle at the current cooling time, and acquire the battery cooling time of the target vehicle; the battery cooling time is the time from the battery start cooling time of the target vehicle to the current cooling time; an adjustment information acquisition module, configured to acquire a basic opening and a composite opening of the electronic expansion valve of the target vehicle at the current cooling moment according to the ambient temperature and the vehicle speed information, and to acquire an opening adjustment rate of the electronic expansion valve at the current cooling moment according to the vehicle speed information; A target opening acquisition module is used to obtain the target opening of the electronic expansion valve at the current cooling moment according to the basic opening, the compound opening, the opening adjustment rate and the battery cooling time; the target opening is used to control the opening of the electronic expansion valve at the current cooling moment to be adjusted to the target opening.

12. A controller comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 10 are implemented.

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