Electric Vehicle Charging Current Control Method and Electric Vehicle

Abstract

The present invention relates to the technical field of electric vehicles. The present invention discloses a method for controlling the charging current of an electric vehicle and an electric vehicle. The method includes: after determining that the charging battery of the electric vehicle is in a charging state, obtaining the allowable charging current and the offset current of the charging battery, and controlling the high-voltage device to enter a downshift delay state; when it is detected that the high-voltage device is in a working state, if it is detected in real time that the high-voltage device meets the preset delay downshift condition, adjusting the charging current of the charging battery to the sum of the allowable charging current and the offset current; after a first preset time period, controlling the high-voltage device to perform a downshift action; after a second preset time period for performing the downshift action, adjusting the charging current of the charging battery to the sum of the allowable charging current, the offset current, and the consumption current of the high-voltage device. The present invention maximally utilizes the battery charging capacity, reduces the charging time, and avoids the occurrence of overcharging of the battery, ensuring the safety of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicles, and particularly to a method for controlling the charging current of an electric vehicle and an electric vehicle. Background Art

[0002] At present, with the increasing popularity of new energy vehicles (such as electric vehicles), charging time and cruising range are two major factors that need to be concerned about in new energy vehicles. Moreover, the length of the charging time of the charging battery also affects the cruising range: when the charging time is short, users can obtain a longer cruising range by spending less time, which will alleviate range anxiety to a certain extent.

[0003] In the prior art, when an electric vehicle is charging, it often determines the charging current (i.e., the allowable charging current of the charging battery) only according to the charging ability of the battery itself. Thus, when high-voltage devices are started, such as starting a high-voltage heater when there is a heating demand in the passenger compartment, a part of the electric power will be consumed; according to Kirchhoff's current law, at this time, the actual charging current entering the charging battery in the charging circuit will be lower than the current allowable charging current of the battery, so the charging ability of the battery cannot be maximally utilized, and the charging time of the battery is prolonged. Summary of the Invention

[0004] Based on this, it is necessary to provide a method for controlling the charging current of an electric vehicle and an electric vehicle for the above technical problems, so as to solve the problems that when charging with high-voltage devices started, the charging ability of the battery cannot be maximally utilized, and the charging time of the battery is prolonged, etc.

[0005] A method for controlling the charging current of an electric vehicle is applied to a control module of the electric vehicle; the method for controlling the charging current of the electric vehicle includes:

[0006] After determining that the charging battery of the electric vehicle is in a charging state, obtain the allowable charging current and the offset current of the charging battery, and control the high-voltage device to enter a downshift delay state;

[0007] When it is detected that the high-voltage device is in a working state, if it is detected in real time that the high-voltage device meets a preset delay downshift condition, adjust the charging current of the charging battery to the sum of the allowable charging current and the offset current;

[0008] After a first preset time period, control the high-voltage device to perform a downshift operation;

[0009] After a second preset time period for performing the downshift operation, adjust the charging current of the charging battery to the sum of the allowable charging current, the offset current, and the consumption current of the high-voltage device.

[0010] An electric vehicle, comprising a control module, a charging battery and high-voltage devices, wherein the control module is used to execute the electric vehicle charging current control method described above.

[0011] In the above-mentioned electric vehicle charging current control method and electric vehicle, in the electric vehicle charging current control method, after determining that the charging battery of the electric vehicle is in a charging state, obtain the allowable charging current and the offset current of the charging battery, and control the high-voltage device to enter a downshift delay state; when it is detected that the high-voltage device is in a working state, if it is detected in real time that the high-voltage device meets the preset delay downshift condition, then adjust the charging current of the charging battery to the sum of the allowable charging current and the offset current; after a first preset time period, control the high-voltage device to perform a downshift operation; after a second preset time period for performing the downshift operation, adjust the charging current of the charging battery to the sum of the allowable charging current, the offset current and the consumption current of the high-voltage device.

[0012] When the present invention charges the charging battery and the high-voltage device is in a stable working state, on the basis of the allowable charging current, the consumption current of the high-voltage device is superimposed, so as to make the most of the battery charging capacity and reduce the charging time.

[0013] At the same time, the present invention aims at the problem that the high-voltage device may be frequently shifted during operation (when the high-voltage device downshifts, the consumption current will suddenly decrease. At this time, due to a certain delay in the output response of the charging device, the charging current output by the charging device cannot follow the sudden decrease in the consumption current caused by the downshift of the high-voltage device in time, so the actual charging current provided by the charging device for the charging battery will continue to maintain a higher value higher than the allowable charging current for a period of time thereafter, causing the battery overcharge phenomenon and affecting the battery safety). As long as the charging battery is in a charging state, the high-voltage device is controlled to be in a downshift delay state; furthermore, when it is detected that the high-voltage device is in a working state and meets the preset delay downshift condition, the consumption current of the high-voltage device is not superimposed, avoiding the generation of the battery overcharge phenomenon and ensuring the battery safety.

[0014] Moreover, the present invention considers the response delay problem of the charging device and controls the high-voltage device to actually perform a downshift operation only after a first preset time period; after a second preset time period (the high-voltage device will be in a stable working state again) for performing the downshift operation, the consumption current of the high-voltage device is superimposed again on the basis of the allowable charging current, so as to make the most of the battery charging capacity again and further reduce the charging time. Description of the Drawings

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 is a schematic flowchart of a method for controlling the charging current of an electric vehicle according to an embodiment of the present invention;

[0017] Figure 2 is a schematic flowchart of step S20 of the method for controlling the charging current of an electric vehicle according to an embodiment of the present invention;

[0018] Figure 3 is a schematic structural diagram of an electric vehicle according to an embodiment of the present invention.

[0019] The reference numerals in the specification are as follows:

[0020] 1. Control module; 11. Vehicle controller; 12. Air conditioner controller; 2. High-voltage device; 3. Charging battery; 4. Battery management system; 5. Charging device; 6. Power distribution unit; 7. Other high-voltage accessories. Specific embodiments

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0022] The method for controlling the charging current of an electric vehicle provided in this embodiment, as Figure 1 shown, is applied to the control module of the electric vehicle; wherein the control module is installed on the electric vehicle, and the control module can include one or more modules. The method for controlling the charging current of the electric vehicle includes the following steps:

[0023] S10. After determining that the charging battery of the electric vehicle is in the charging state, obtain the allowable charging current and the offset current of the charging battery, and control the high-voltage device to enter the downshift delay state; wherein, the charging battery is installed on the electric vehicle and provides driving force for the electric vehicle. The charging state means that the electric vehicle is charging the charging battery through a charging device installed on the electric vehicle (which can also be set outside the electric vehicle according to requirements). The allowable charging current refers to the maximum charging current that the charging device is allowed to provide when the charging battery is in the charging state but not overcharged. The offset current is a preset current offset value to ensure the stability of the high-voltage system of the electric vehicle (the high-voltage device refers to one or more high-voltage devices in the high-voltage system, such as a high-voltage heater), and the offset current can be associated with relevant parameters of the charging battery and stored in the preset storage area of the electric vehicle.

[0024] Understandably, after confirming that the charging battery enters the charging state (charging state in DC charging or AC charging mode), the control module controls the high-voltage device to enter the downshift delay state in real time, and at the same time obtains the above-mentioned charging current (which can be obtained from the battery management system of the electric vehicle) and the offset current (which can be retrieved from the preset storage area); at the same time, control the high-voltage device to enter the downshift delay state. The high-voltage device entering the downshift delay state means that when the high-voltage device meets the preset delay downshift condition (set as different conditions according to different high-voltage devices), it needs to actually execute the downshift action after delaying for the first preset duration (the first preset duration can be set according to requirements).

[0025] Further, in the step S10, the determination that the charging battery of the electric vehicle is in the charging state includes: sending a charging request for charging the charging battery to the battery management system of the electric vehicle, and after the battery management system obtains the real-time charging information of the charging battery, confirming that the charging battery is in the charging state. Specifically, the control module 1 (such as Figure 3In the illustrated embodiment, the vehicle controller 11) sends a charging request to charge the charging battery 3 to the battery management system 4. After that, the battery management system 4 instructs the charging device 5 to start direct current charging or alternating current charging of the charging battery 3 to make the charging battery 3 enter the charging state. At this time, the battery management system 4 obtains the real-time charging information of the charging battery 3 in the charging state. Among them, the real-time charging information includes but is not limited to the current battery temperature, SOC of the charging battery 3, and the single cell voltage of the single cells in the charging battery 3 (the single cells in the battery pack), etc. Furthermore, the battery management system 4 can send the relevant information of the charging battery 3 in the charging state (such as the allowable charging current of the charging battery 3 determined according to the real-time charging information, the direct current charging or alternating current charging mode, etc.) to the control module 1. In this way, the control module 1 can confirm that the charging battery 3 is in the charging state.

[0026] Further, in step S10, the obtaining of the allowable charging current of the charging battery 3 includes: obtaining the allowable charging current determined by the battery management system 4 according to the current battery temperature, SOC, and single cell voltage included in the real-time charging information of the charging battery 3. That is to say, the battery management system 4 can determine the allowable charging current of the charging battery 3 according to the real-time charging information. That is, according to the parameters such as the current battery temperature, SOC, and single cell voltage in the real-time charging information, the allowable charging current of the charging battery 3 is queried from the battery data table pre-stored in the preset storage area of the electric vehicle.

[0027] In one embodiment, as Figure 3 shown, the high-voltage device 2 is a high-voltage heater; the control module 1 includes a vehicle controller 11 and an air-conditioning controller 12, and the air-conditioning controller 12 is connected (which can be a communication connection or an electrical connection) to the vehicle controller 11 and the high-voltage heater. Step S10 includes: after the vehicle controller 11 determines that the charging battery 3 of the electric vehicle is in the charging state, obtaining the allowable charging current and the offset current of the charging battery 3, and sending a downshift delay enable flag bit to the air-conditioning controller 12 to make the air-conditioning controller 12 control the high-voltage heater to enter the downshift delay state according to the received downshift delay enable flag bit.

[0028] Understandably, after confirming that the battery enters the charging state (the charging state in the direct current charging or alternating current charging mode), the control module controls the high-voltage device to enter the downshift delay state in real time, and at the same time, obtains the above-mentioned charging current (which can be obtained from the battery management system) and the offset current (which can be retrieved from the preset storage area); further, in Figure 3In the embodiment shown, after the vehicle controller 11 determines that the charging battery 3 of the electric vehicle is in a charging state, the vehicle controller 11 sends a downshift delay enable flag bit to the air conditioner controller 12 in real time. At this time, the air conditioner controller 12 controls the high-voltage device 2 to enter the downshift delay state in real time; that is, when the air conditioner controller 12 receives the downshift delay enable flag bit, it will continuously determine whether the high-voltage heater it controls meets the preset delay downshift condition. As long as the air conditioner controller 12 determines that the high-voltage heater meets the preset delay downshift condition, the air conditioner controller 12 needs to delay the downshift action of the actually controlled high-voltage heater (it cannot downshift immediately when it determines that the high-voltage heater it controls meets the preset delay downshift condition). The high-voltage heater entering the downshift delay state means that when the high-voltage heater meets the preset delay downshift condition, it needs to actually execute the downshift action after delaying for the first preset duration (the first preset duration can be set according to requirements).

[0029] Further, after controlling the high-voltage device to enter the downshift delay state, it further includes: when detecting that the high-voltage device is in a non-operating state, adjusting the charging current of the charging battery to the sum of the allowable charging current and the offset current. That is, when the high-voltage device is in a non-operating state, it means that there is no corresponding operating gear for the high-voltage device currently, so it is impossible to meet the preset delay downshift condition. At this time, the high-voltage device will not consume power or generate a consumption current. Therefore, at this time, it is only necessary to ensure that the charging current of the charging battery is the sum of the allowable charging current and the offset current.

[0030] S20, when detecting that the high-voltage device is in an operating state, if it is detected in real time that the high-voltage device meets the preset delay downshift condition, adjust the charging current of the charging battery to the sum of the allowable charging current and the offset current; it can be understood that when the high-voltage device is in an operating state, it means that there is a corresponding operating gear for the high-voltage device currently, and the high-voltage device will consume power (as Figure 3 shown, when the high-voltage device 2 is a high-voltage heater and the control module 1 includes the vehicle controller 11 and the air conditioner controller 12, the air conditioner controller 12 will detect the power consumption of the high-voltage heater and send it to the vehicle controller 11) and generate a corresponding consumption current, and may also meet the preset delay downshift condition. In the present invention, before detecting that the high-voltage device meets the preset delay downshift condition, the operating state of the high-voltage device is divided into a stable state and an unstable state, which are respectively described as follows:

[0031] When charging a rechargeable battery and the high-voltage device is in a stable operating state, based on the allowable charging current, the present invention will superimpose the initial consumption current of the high-voltage device (the initial consumption current is the consumption current corresponding to the high-voltage device before it is detected to meet the preset delay downshift condition); therefore, before it is detected that the high-voltage device meets the preset delay downshift condition, the charging current of the rechargeable battery is the sum of the allowable charging current, the offset current, and the initial consumption current of the high-voltage device. Therefore, starting from the moment when it is detected in real time that the high-voltage device meets the preset delay downshift condition, it will be necessary to reduce and adjust the charging current of the rechargeable battery to the sum of the allowable charging current and the offset current. The main purpose of this adjustment is as follows: within a certain period of time starting from the moment when it is detected in real time that the high-voltage device meets the preset delay downshift condition, for example, within the total duration obtained by adding the subsequent consecutive first preset duration and the second preset duration mentioned later, within the first preset duration, it is necessary to avoid overcharging caused by the output response delay of the charging device by no longer superimposing the consumption current of the high-voltage device on the charging current of the rechargeable battery; and a downshift operation is performed after the first preset duration. Therefore, within the second preset duration after the downshift operation is performed, since the high-voltage device will be in an unstable operating state due to the execution of the downshift operation, its consumption current will also fluctuate. Therefore, at this time, it is also necessary to avoid fluctuations in the charging current by no longer superimposing the consumption current of the high-voltage device on the charging current of the rechargeable battery.

[0032] When charging a rechargeable battery and the high-voltage device is in an unstable operating state (for example, there is no interval of the second preset duration between the current time point and the execution time point of the previous downshift operation), the present invention does not superimpose the initial consumption current of the high-voltage device on the basis of the allowable charging current; therefore, before it is detected that the high-voltage device meets the preset delay downshift condition, the charging current of the rechargeable battery is the sum of the allowable charging current and the offset current; therefore, starting from the moment when it is detected in real time that the high-voltage device meets the preset delay downshift condition, it is only necessary to continue to maintain the charging current of the rechargeable battery as the sum of the allowable charging current and the offset current.

[0033] Further, as Figure 3 shown, the high-voltage device 2 is a high-voltage heater; the control module 1 includes a vehicle controller 11 and an air-conditioning controller 12, and the air-conditioning controller 12 is connected (which can be a communication connection or an electrical connection) to the vehicle controller 11 and the high-voltage heater; as Figure 2 shown, the step S20 includes:

[0034] S201, the vehicle controller 11 detects whether the high-voltage heater is in an operating state through the air-conditioning controller 12; when the high-voltage heater is not in the off state (non-operating state), it is considered to be in an operating state.

[0035] S202. When it is detected that the high-pressure heater is in the working state, the air-conditioning controller 12 is used to detect in real time whether the high-pressure heater meets the preset delay downshift condition.

[0036] Further, when the high-voltage device 2 is a high-pressure heater; after it is detected that the high-voltage device 2 is in the working state, it further includes: obtaining the actual water temperature and the target water temperature of the heating circuit currently heated by the high-pressure heater in the working state; when the temperature difference between the actual water temperature and the target water temperature is greater than a preset difference value, it is confirmed that the high-pressure heater meets the preset delay downshift condition; when the temperature difference between the actual water temperature and the target water temperature is less than or equal to the preset difference value, it is confirmed that the high-pressure heater does not meet the preset delay downshift condition. That is to say, when the high-voltage device 2 is a high-pressure heater, the air-conditioning controller 12 can determine whether to downshift through the actual water temperature and the target water temperature in the heating circuit currently heated by the high-pressure heater. When the temperature difference between the actual water temperature and the target water temperature is greater than the preset difference value (set according to requirements), it is considered that the current high-pressure heater needs to downshift. At this time, it is confirmed that the high-pressure heater meets the preset delay downshift condition. Correspondingly, when the temperature difference between the actual water temperature and the target water temperature is less than or equal to the preset difference value, it is considered that the current high-pressure heater does not need to downshift. At this time, it is confirmed that the high-pressure heater does not meet the preset delay downshift condition.

[0037] S203. If it is detected that the high-pressure heater meets the preset delay downshift condition, the vehicle controller 11 receives the downshift flag fed back by the air-conditioning controller 12, and confirms that the high-pressure heater will perform the downshift action after a first preset duration according to the received downshift flag; that is to say, when the temperature difference between the actual water temperature and the target water temperature is greater than the preset difference value, it is confirmed that the high-pressure heater meets the preset delay downshift condition. However, since in step S10 before, the high-pressure heater has been in the downshift delay state under the control of the air-conditioning controller 12, even when the current high-pressure heater meets the preset delay downshift condition, it still needs to actually perform the downshift action after delaying for the first preset duration (the first preset duration can be set according to requirements). Therefore, the air-conditioning controller 12 needs to first feed back the downshift flag to the vehicle controller 11, and this downshift flag indicates that the high-pressure heater is in the downshift state, but will perform the downshift action after delaying for the first preset duration.

[0038] In S204, the vehicle controller 11 adjusts the charging current of the charging battery 3 to the sum of the allowable charging current and the offset current. That is, when receiving the downshift flag, the vehicle controller 11 adjusts the charging current of the charging battery 3 in real time to: I_Req = I_chg + ΔI; where ΔI is the offset current; I_Req is the charging current of the charging battery 3; I_chg is the allowable charging current, thereby avoiding overcharging phenomena and fluctuations in the charging current caused by the output response delay of the charging device 5.

[0039] Further, in the step S202, after the air conditioner controller 12 detects in real time whether the high-voltage heater meets the preset delay downshift condition, it further includes:

[0040] If it is detected that the high-voltage heater does not meet the preset delay downshift condition, the vehicle controller 11 receives the non-downshift flag fed back by the air conditioner controller 12 and confirms that the high-voltage heater will not perform a downshift action currently according to the received non-downshift flag; that is, when the temperature difference between the actual water temperature and the target water temperature is less than or equal to the preset difference, it is considered that the current high-voltage heater does not need to downshift. At this time, it is confirmed that the high-voltage heater does not meet the preset delay downshift condition, and the air conditioner controller 12 needs to first feed back the non-downshift flag to the vehicle controller 11. This non-downshift flag represents that the high-voltage heater is in a non-downshift state, and the high-voltage heater currently does not need to perform a downshift action.

[0041] The vehicle controller 11 adjusts the charging current of the charging battery 3 to the sum of the allowable charging current, the offset current, and the consumption current of the high-voltage heater. That is, when receiving the downshift flag, the vehicle controller 11 adjusts the charging current of the charging battery 3 in real time to: I_Req = I_chg + I_heater + ΔI; where ΔI is the offset current; I_Req is the charging current of the charging battery 3; I_chg is the allowable charging current; I_heater is the consumption current of the high-voltage heater. Furthermore, on the basis of the allowable charging current, the consumption current of the high-voltage device 2 is superimposed, thereby maximizing the use of the battery charging capacity and reducing the charging time.

[0042] S30. After the first preset duration, control the high-voltage device to perform a downshift operation. That is, since in step S10 above, the high-voltage device has been in the downshift delay state, even if it is detected in step S20 that the high-voltage device meets the preset delay downshift condition, it is still necessary to actually perform the downshift operation after delaying for the first preset duration (the first preset duration can be set according to requirements) (to avoid overcharging phenomena caused by the output response delay of the charging device). After the downshift operation here is completed, the high-voltage device may be in a non-operating state (turned off), or it may just be reduced to a lower gear for operation (still in the operating state, but the power consumption for work has decreased).

[0043] S40. After the second preset duration of performing the downshift operation, adjust the charging current of the charging battery to the sum of the allowed charging current, the offset current, and the consumption current of the high-voltage device. That is, after the downshift operation is performed, it takes a second preset duration to make the working state of the high-voltage device return from an unstable state to a stable working state. Therefore, within the second preset duration of performing the downshift operation, the charging current will be maintained at the sum of the allowed charging current and the offset current. After the second preset duration, since the output response delay problem of the charging device has been solved within the first preset duration, and the working state of the high-voltage device has returned from an unstable state to a stable working state, at this time, in order to make the most of the battery charging capacity and reduce the charging time, it is necessary to clear the original downshift state of the high-voltage device and modify it to a non-downshift state. Furthermore, after the non-downshift state of the high-voltage device is fed back to the control module, the control module, on the basis of the allowed charging current, adds the consumption current of the high-voltage device again. That is, adjust the charging current of the charging battery to the sum of the allowed charging current, the offset current, and the consumption current of the high-voltage device.

[0044] Specifically, after the downshift operation is completed, if the high-voltage device is just reduced to a lower gear for operation, at this time, it is still necessary to add the consumption current of the high-voltage device on the basis of the allowed charging current. Therefore, adjust the charging current of the charging battery to the sum of the allowed charging current, the offset current, and the consumption current of the high-voltage device.

[0045] After the downshift operation is completed and the high-voltage device is turned off and in a non-operating state, the charging current of the charging battery is actually the sum of the allowed charging current and the offset current (because the consumption current of the high-voltage device is 0 at this time). However, when the high-voltage device restarts from the non-operating state and enters the operating state again, the charging current of the charging battery will automatically change to the sum of the allowed charging current, the offset current, and the consumption current of the high-voltage device (because the consumption current of the high-voltage device is no longer 0). But if the charging current is not adjusted in step S40 above, within the current charging cycle of the charging battery, the power consumption of the high-voltage device will no longer be considered. Therefore, the charging current of the charging battery will always remain the sum of the allowed charging current and the offset current, even if the high-voltage device changes gears again or restarts from the non-operating state and enters the operating state again.

[0046] Optionally, in step S40, before adjusting the charging current of the charging battery to the sum of the allowed charging current, the offset current, and the consumption current of the high-voltage device, it includes: determining the consumption current of the high-voltage device according to the consumption power of the high-voltage device and the current voltage of the charging battery. That is, Figure 3 In the illustrated embodiment, when the high-voltage device 2 is a high-voltage heater and the control module 1 includes a vehicle controller 11 and an air-conditioning controller 12, the vehicle controller 11 calculates the consumption current of the high-voltage heater according to the consumption power P_heater of the high-voltage heater sent by the air-conditioning controller 12 and the current voltage U of the charging battery 3, that is: I_heater = P_heater / U. In this embodiment, since the vehicle controller 11 and the air-conditioning controller 12 use power interaction when interacting, the vehicle controller 11 needs to convert the consumption current according to the consumption power of the high-voltage heater. At the same time, since all high-voltage components of the electric vehicle (including the high-voltage device 2 and other high-voltage accessories 7) are in a parallel connection state and the power is distributed through the power distribution unit 6, and there is a certain voltage drop from the charging battery 3 to each high-voltage component, therefore, here, using the current voltage of the charging battery 3 to calculate the consumption current of the high-voltage device 2 will be smaller than the actual consumption current value. Furthermore, considering the actual impact of the control error on the charging current, the smaller consumption current can avoid the overcharging phenomenon of the charging current to a certain extent.

[0047] When the present invention charges the charging battery and the high-voltage device is in a stable operating state, on the basis of the allowed charging current, the consumption current of the high-voltage device is superimposed, thus maximizing the battery charging capacity and reducing the charging time.

[0048] Meanwhile, in view of the problem that the high-voltage device may frequently shift gears during operation (downshifting of the high-voltage device will cause the consumption current to suddenly decrease. At this time, due to a certain delay in the output response of the charging device, the charging current output by the charging device cannot promptly follow the sudden decrease in the consumption current caused by the downshifting of the high-voltage device and be adjusted in a timely manner. Therefore, the actual charging current provided by the charging device for the rechargeable battery will continue to be maintained at a relatively high value higher than the allowable charging current for a period of time thereafter, resulting in overcharging of the battery and affecting battery safety), as long as the rechargeable battery is in the charging state, the high-voltage device is controlled to be in the downshift delay state; furthermore, when it is detected that the high-voltage device is in the working state and meets the preset delay downshift condition, the consumption current of the high-voltage device is not superimposed, thus avoiding the occurrence of battery overcharging and ensuring battery safety.

[0049] Moreover, considering the response delay problem of the charging device, the high-voltage device is controlled to actually perform the downshift operation only after the first preset time period; after the second preset time period (when the high-voltage device will return to the stable working state) of performing the downshift operation, the consumption current of the high-voltage device is superimposed on the basis of the allowable charging current again, thereby maximizing the utilization of the battery charging capacity and further reducing the charging time.

[0050] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not imply the order of execution. The execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0051] The present invention also provides an electric vehicle, including a control module 1, a rechargeable battery 3, and a high-voltage device 2. The control module 1 is used to execute the electric vehicle charging current control method described above. Further, as Figure 3 shown, the high-voltage device 2 is a high-voltage heater; the control module 1 includes a vehicle controller 11 and an air-conditioning controller 12. The air-conditioning controller 12 is connected (which can be a communication connection or an electrical connection) to the vehicle controller 11 and the high-voltage heater. Further, the electric vehicle also includes a battery management system 4, a charging device 5, a power distribution unit 6, and other high-voltage accessories 7. The vehicle controller 11 is connected to the battery management system 4 and the charging device 5 (which can be a communication connection or an electrical connection). The charging device 5 is connected to the rechargeable battery 3 through a high-voltage wire; the rechargeable battery 3 is connected to the power distribution unit 6 through a high-voltage wire. The power distribution unit 6 is connected to each high-voltage component (including the high-voltage device 2 and other high-voltage accessories 7) through a high-voltage wire and distributes power to them; and all high-voltage components are connected in parallel.

[0052] For the specific limitations of the control module 1, reference can be made to the limitations on the electric vehicle charging current control method in the foregoing text, which will not be elaborated here. Each module in the above control module 1 can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in the processor of the computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so as to facilitate the processor to call and execute the operations corresponding to the above respective modules.

[0053] Those skilled in the art can clearly understand that, for the convenience and conciseness of description, only the above division of each functional unit and module is used as an example. In actual applications, the above functions can be allocated to different functional units and modules according to needs, that is, the internal structure of the system is divided into different functional units or modules to complete all or part of the functions described above.

[0054] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for controlling the charging current of an electric vehicle, characterized in that, Control module applied to electric vehicle; the electric vehicle charging current control method includes: After determining that the charging battery of the electric vehicle is in a charging state, obtain the allowable charging current and the offset current of the charging battery, and control the high-voltage device to enter the downshift delay state; On the basis of the allowable charging current, adjust the charging current of the charging battery to the sum of the allowable charging current, the offset current, and the initial consumption current of the high-voltage device; When it is detected that the high-voltage device is in a working state, if it is detected in real time that the high-voltage device meets the preset delay downshift condition, adjust the charging current of the charging battery to the sum of the allowable charging current and the offset current; After the first preset time period, control the high-voltage device to perform a downshift action; After the second preset time period of performing the downshift action, adjust the charging current of the charging battery to the sum of the allowable charging current, the offset current, and the consumption current of the high-voltage device.

2. The electric vehicle charging current control method according to claim 1, wherein The high-voltage device is a high-voltage heater; the control module includes a vehicle controller and an air-conditioning controller, and the air-conditioning controller is connected to the vehicle controller and the high-voltage heater; The step of, after determining that the charging battery of the electric vehicle is in a charging state, obtaining the allowable charging current and the offset current of the charging battery, and controlling the high-voltage device to enter the downshift delay state, includes: After the vehicle controller determines that the charging battery of the electric vehicle is in a charging state, obtain the allowable charging current and the offset current of the charging battery, and send a downshift delay enable flag bit to the air-conditioning controller, so that the air-conditioning controller controls the high-voltage heater to enter the downshift delay state according to the received downshift delay enable flag bit.

3. The electric vehicle charging current control method according to claim 1, wherein The high-voltage device is a high-voltage heater; the control module includes a vehicle controller and an air-conditioning controller, and the air-conditioning controller is connected to the vehicle controller and the high-voltage heater; The step of, when it is detected that the high-voltage device is in a working state, if it is detected in real time that the high-voltage device meets the preset delay downshift condition, adjusting the charging current of the charging battery to the sum of the allowable charging current and the offset current, includes: The vehicle controller detects whether the high-voltage heater is in a working state through the air-conditioning controller; When it is detected that the high-voltage heater is in a working state, detect in real time through the air-conditioning controller whether the high-voltage heater meets the preset delay downshift condition; If it is detected that the high-voltage heater meets the preset delay downshift condition, the vehicle controller receives the downshift flag fed back by the air-conditioning controller, and confirms that the high-voltage heater will perform a downshift action after delaying to the first preset time period according to the received downshift flag; The vehicle controller adjusts the charging current of the charging battery to the sum of the allowable charging current and the offset current.

4. The electric vehicle charging current control method according to claim 3, wherein, After the step of detecting in real time through the air-conditioning controller whether the high-voltage heater meets the preset delay downshift condition, it further includes: If it is detected that the high-voltage heater does not meet the preset delay downshift condition, the vehicle controller receives the non-downshift flag fed back by the air-conditioning controller, and confirms that the high-voltage heater will not perform a downshift action currently according to the received non-downshift flag; The vehicle controller adjusts the charging current of the charging battery to the sum of the allowed charging current, the offset current, and the consumption current of the high-voltage heater.

5. The method for controlling the charging current of an electric vehicle according to claim 1, characterized in that, After the control of the high-voltage device enters the downshift delay state, it further includes: When it is detected that the high-voltage device is in a non-operating state, the charging current of the charging battery is adjusted to the sum of the allowed charging current and the offset current.

6. The electric vehicle charging current control method according to claim 1, characterized in that, The determination that the charging battery of the electric vehicle is in a charging state includes: Sending a charging request for charging the charging battery to the battery management system of the electric vehicle, and after the battery management system obtains the real-time charging information of the charging battery, confirming that the charging battery is in a charging state.

7. The method for controlling the charging current of an electric vehicle according to claim 6, wherein, The obtaining of the allowed charging current of the charging battery includes: Obtaining the allowed charging current determined by the battery management system according to the current battery temperature, SOC, and single-cell voltage included in the real-time charging information.

8. The electric vehicle charging current control method according to claim 1, characterized in that, The high-voltage device is a high-voltage heater; After it is detected that the high-voltage device is in an operating state, it further includes: Obtaining the actual water temperature and the target water temperature of the heating circuit currently heated by the high-voltage heater in the operating state. When the temperature difference between the actual water temperature and the target water temperature is greater than a preset difference, it is confirmed that the high-voltage heater meets the preset delay downshift condition; When the temperature difference between the actual water temperature and the target water temperature is less than or equal to the preset difference, it is confirmed that the high-voltage heater does not meet the preset delay downshift condition.

9. The electric vehicle charging current control method according to claim 1, characterized in that Before adjusting the charging current of the charging battery to the sum of the allowed charging current, the offset current, and the consumption current of the high-voltage device, it includes: Determining the consumption current of the high-voltage device according to the consumption power of the high-voltage device and the current voltage of the charging battery.

10. An electric vehicle, characterized in that, It includes a control module, a charging battery, and a high-voltage device, and the control module is used to execute the electric vehicle charging current control method according to any one of claims 1 to 9.

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