Charging control method, charging system and vehicle

Abstract

The invention provides a charging control method, a charging system and a vehicle, and the charging control method comprises the steps: controlling a battery pack to enter a low-power cooling charging state when the voltage difference is greater than a preset voltage difference threshold value and the duration reaches a preset duration threshold value; in the low-power cooling charging state, whether overvoltage and / or over-temperature exists in the battery pack is detected; if not, the parameter information of the charging pile is sent to the cloud, and the state of the charging pile is determined through the cloud; and when the state of the charging pile is a non-fault state, controlling the charging pile to charge the battery pack. Under the condition that the voltage difference between the two ends of the relay and the duration threshold exceed the standard, whether overvoltage or over-temperature exists in the battery pack is detected by controlling the battery pack to enter the low-power cooling charging state, the state of the charging pile is judged through the cloud end, and it is determined that the threshold exceeds the standard due to electromagnetic interference or charging pile faults. And controlling the charging pile to charge the battery pack when the charging pile is in a non-fault state.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a charging control method, a charging system and a vehicle. Background Art

[0002] During the charging process, new energy vehicles need to detect the normal working status of the relay. Once a relay failure such as melting is detected, the relay will be forcibly disconnected to stop charging the battery pack in order to ensure charging safety.

[0003] However, during the charging process, the detection of the relay may be affected by electromagnetic interference from the external environment. Especially when charging with a fast charging pile, the electromagnetic environment interference of the charging pile may cause the relay to be misjudged as melted during detection, resulting in the vehicle being unable to charge normally and causing customer complaints.

[0004] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0005] The main purpose of the present invention is to provide a charging control method, a charging system and a vehicle, aiming to solve the technical problem in the prior art that due to the interference of the electromagnetic environment of the charging pile, the relay is misjudged to be melted during relay detection, resulting in the inability to charge the vehicle normally.

[0006] To achieve the above object, the present invention proposes a charging control method, which is applied to an electric vehicle. The charging control method comprises:

[0007] When the battery pack is charged, detecting a voltage difference across the relay and a duration of the voltage difference;

[0008] When the voltage difference is greater than a preset voltage difference threshold and the duration reaches a preset duration threshold, the battery pack is controlled to enter a low-power cooling charging state, where the low-power cooling charging state is a charging state in which the charging power is less than the rated charging power and the battery pack cooling system is turned on;

[0009] In the low-power cooling charging state, detecting whether the battery pack has overvoltage and / or overtemperature;

[0010] If not, the parameter information of the charging pile is sent to the cloud, and the charging pile status is determined through the cloud;

[0011] When the charging pile is in a non-fault state, the charging pile is controlled to charge the battery pack.

[0012] Optionally, during the charging process of the battery pack, a voltage difference across the relay and a duration of the voltage difference are detected, and the method also includes:

[0013] Get the parameter information of the charging pile;

[0014] The preset voltage difference threshold and the preset time threshold corresponding to the charging pile are extracted according to the parameter information.

[0015] Optionally, when the charging pile is in a non-fault state, controlling the charging pile to charge the battery pack, further comprising:

[0016] When the battery pack is charged, detecting a voltage difference set at both sides of the relay and a duration corresponding to each voltage difference in the voltage difference set;

[0017] The preset voltage difference threshold and the preset duration threshold in the parameter information are updated according to the maximum voltage difference in the voltage difference set and the maximum duration corresponding to the maximum voltage difference.

[0018] Optionally, after updating the preset voltage difference threshold and the preset duration threshold in the parameter information by using the maximum voltage difference in the voltage difference set and the maximum duration corresponding to the maximum voltage difference, the method further includes:

[0019] Sending the new preset voltage difference threshold and the preset time threshold to the cloud for storage;

[0020] The interference level of each charging pile is obtained by sorting the interference level of each charging pile according to the new preset voltage difference threshold and the preset time threshold through the cloud;

[0021] When a charging demand is detected, the interference level of each charging pile is output through the cloud.

[0022] Optionally, when the charging demand is detected, the interference level of each charging pile is output through the cloud, and then the method further includes:

[0023] Detect whether the user has changed the charging pile;

[0024] If not, return to the step of controlling the battery pack to enter a low-power cooling charging state.

[0025] Optionally, before sending the parameter information of the charging pile to the cloud and judging the status of the charging pile through the cloud, the method further includes:

[0026] Determine interference source information according to the parameter information and the vehicle map;

[0027] The step of sending the parameter information of the charging pile to the cloud and determining the status of the charging pile through the cloud includes:

[0028] Sending the parameter information and the interference source information to the cloud;

[0029] The cloud extracts historical fault information of the charging pile according to the parameter information, and determines the state of the charging pile according to the historical fault information and the interference source information.

[0030] Optionally, when the voltage difference is greater than a preset voltage difference threshold and the duration reaches a preset duration threshold, controlling the battery pack to enter a low-power cooling charging state includes:

[0031] When the voltage difference is greater than a preset voltage difference threshold and the duration reaches a preset duration threshold, starting the pre-charging of the battery pack;

[0032] When the pre-charging of the battery pack is completed, the battery pack is controlled to enter a low-power cooling charging state.

[0033] Optionally, when the voltage difference is greater than a preset voltage difference threshold and the duration reaches a preset duration threshold, starting the pre-charging of the battery pack includes:

[0034] Detecting whether the voltage difference is greater than an upper threshold voltage and whether a duration corresponding to the voltage difference reaches an upper threshold duration;

[0035] When the voltage difference is not greater than the upper threshold voltage, or when the voltage difference is greater than the upper threshold voltage but the threshold duration does not reach the upper threshold duration, the battery pack pre-charging is started.

[0036] In addition, to achieve the above-mentioned purpose, the present invention also provides a charging system, which includes: a controller, a fast charging branch and a slow charging branch, the fast charging branch is connected to the fast charging interface and the battery pack respectively, and the slow charging branch is connected to the slow charging interface and the battery pack respectively; the controller is connected to the relays in the fast charging branch and the slow charging branch; the controller is used to execute the charging control method.

[0037] In addition, to achieve the above-mentioned purpose, the present invention also provides a vehicle, which includes: the above-mentioned charging system.

[0038] The present invention provides a charging control method, a charging system and a vehicle. The charging control method detects the voltage difference between the two ends of the relay and the duration of the voltage difference when the battery pack is charged; when the voltage difference is greater than a preset voltage difference threshold and the duration reaches a preset duration threshold, the battery pack is controlled to enter a low-power cooling charging state, the low-power cooling charging state being a charging state in which the charging power is less than the rated charging power and the battery pack cooling system is turned on; in the low-power cooling charging state, the battery pack is detected to be over-voltage and / or over-temperature; if not, the parameter information of the charging pile is sent to the cloud, and the charging pile status is determined through the cloud; when the charging pile status is a non-fault state, the charging pile is controlled to charge the battery pack. In the present invention, when the voltage difference between the two ends of the relay and the duration threshold exceed the standard, the battery pack is controlled to enter a low-power cooling charging state to detect whether the battery pack is over-voltage or over-temperature, and the charging pile status is judged by the cloud to determine whether the threshold exceeds the standard due to electromagnetic interference or charging pile failure, and then when the charging pile is in a non-fault state, the charging pile is controlled to charge the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0040] Figure 1 A schematic diagram of the structure of the charging system proposed by the present invention;

[0041] Figure 2 A schematic flow chart of a first embodiment of a charging control method provided by the present invention;

[0042] Figure 3 A circuit diagram of a signal acquisition circuit proposed in this application;

[0043] Figure 4 A first flow chart of a second embodiment of the charging control method provided by the present invention;

[0044] Figure 5 A second flow chart of the second embodiment of the charging control method provided by the present invention;

[0045] Figure 6 A schematic flow chart of a third embodiment of a charging control method provided by the present invention;

[0046] Figure 7 This is a flow chart of a fourth embodiment of the charging control method provided by the present invention.

[0047] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0048] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0051] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0052] Reference Figure 1 , Figure 1 This is a schematic diagram of the structure of the charging system proposed by the present invention. Figure 1 In the embodiment, the charging system includes: a controller, a fast charging branch 10 and a slow charging branch 20, wherein the fast charging branch 10 is connected to the fast charging interface and the battery pack respectively, and the slow charging branch 20 is connected to the slow charging interface and the battery pack respectively; the controller is connected to the relays in the fast charging branch 10 and the slow charging branch 20.

[0053] It should be understood that the process of charging the battery pack using a charging pile generally includes a fast charging mode and a slow charging mode. The slow charging mode uses the slow charging branch 20 for charging, and the fast charging mode uses the fast charging branch 30 for charging. The charging power in the fast charging mode is much greater than the charging power in the slow charging mode. Figure 1In the figure, the slow charging branch includes the PDM controller, the motor inverter, and the main positive relay and the main negative relay. The fast charging branch mainly includes the fast charging positive relay, the main positive relay, the fast charging negative relay and the main negative relay. Among them, in the slow charging mode, the main positive relay and the main negative relay are turned on, and the charging pile inputs the charging voltage through the slow charging interface. The charging voltage is adjusted by the PDM controller and then input into the battery pack to charge the motor; in the fast charging mode, the main positive relay, the main negative relay, the fast charging positive relay and the fast charging negative relay are all turned on, and the charging pile can directly charge the battery pack through the above relays.

[0054] It should be noted that when the charging pile is charging the battery pack, each relay needs to be precisely controlled. Once the relay cannot be turned on or off normally, it will affect the battery pack and the devices in each branch. For example, if the relay is melted, the relay cannot be disconnected normally. At this time, continuing to charge the battery pack may cause overcharge and damage to the battery pack.

[0055] In the actual detection process, whether the relay is melted is mainly determined by whether the voltage value on both sides of the relay is too large and the specific maintenance time of the excessive voltage value. For example, when the vehicle is plugged into the fast charging gun, the battery management system wakes up and starts the relay melting detection; after the relay cut-off command is issued, the voltage value on both sides of the relay is detected through the set detection circuit, and then the voltage difference on both sides of the relay is determined. If the voltage difference exceeds the preset voltage difference threshold and the voltage difference lasts for a long time, it can be determined that the relay is not disconnected normally according to the received cut-off command, but remains in the on state. At this time, the relay needs to be forcibly disconnected to prohibit charging.

[0056] However, in the actual charging process, when the electromagnetic environment of the charging pile is highly disturbed, the voltage difference on both sides of the relay and the corresponding duration caused by the interference exceed the voltage threshold and time threshold pre-set by the battery management system, which will cause the vehicle to be unable to charge.

[0057] In order to solve the above problems, based on the structure of the above charging system, the present invention proposes a first embodiment of a charging control method. Figure 2 , Figure 2 This is a flow chart of the first embodiment of the charging control method proposed by the present invention.

[0058] In this embodiment, the charging control method includes:

[0059] Step S10: When the battery pack is charging, the voltage difference across the relay and the duration of the voltage difference are detected.

[0060] It should be understood that the voltage difference presented on both sides of the relay is different depending on the working state of the relay. When the relay is in the on state, the voltage difference on both sides of the relay is large, and when the relay is in the off state, the voltage difference on both sides of the relay is small. The relay may include a main positive relay, a main negative relay, a fast charge positive relay, and a fast charge slow relay. When the battery pack needs to be charged, it is necessary to determine whether the relay is abnormal. In the case of an abnormality in the relay, it is necessary to stop charging immediately, and when the relay is not abnormal, the charging pile can be controlled to charge the battery pack normally. Detecting whether the relay is abnormal is mainly by detecting the voltage difference on both sides of the relay and the duration corresponding to the voltage difference. When the voltage difference on both sides of the relay is large and the voltage difference lasts for a long time, it can be determined that the relay has a melting abnormality. The duration is the length of time the current voltage difference is maintained. When the voltage difference on both sides of the relay changes, the duration of the changed voltage difference needs to start timing when the voltage difference changes, and stop timing when the voltage difference changes again. The duration between the two timing points is the duration of the voltage difference.

[0061] In the specific implementation, it is necessary to detect the voltage difference on both sides of the relay and record the duration of each voltage difference. In the specific detection, the sampling points at both ends of the relay can be set, and then the data can be collected in real time or by control signal driven collection. Figure 3 , Figure 3 This is a circuit diagram of a signal acquisition circuit proposed in this application. Figure 3 In the structure of optocoupler OC, voltage-dividing resistor and transistor Q, the voltage value of the sampling point is collected. The controller inputs the sampling control signal to the base of the transistor to turn on the transistor Q. At this time, the low-voltage power supply can form a complete conduction branch through the transistor Q and the first resistor R1. The primary side of the optocoupler OC is turned on, generating a light source to control the secondary side of the optocoupler OC to turn on. When the secondary side of the optocoupler OC is turned on, the voltage values ​​on both sides of the relay can be input to the controller through the isolated analog-to-digital converter through the voltage divider of the second resistor R2 and the third resistor R3. Figure 3In the process, the first end of the optical coupler OC is connected to a low-voltage power supply, the second end of the optical coupler OC is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the collector of the transistor Q, the emitter of the transistor Q is connected to the low-voltage ground terminal GND, and the base of the transistor Q is connected to the port for inputting the sampling control signal; the third end of the optical coupler OC is connected to the sampling point of the relay, the fourth end of the optical coupler OC is connected to the first end of the second resistor R2, the second end of the second resistor R2 is respectively connected to the first end of the third resistor R3 and the isolation analog-to-digital converter, and the second end of the third resistor R3 is connected to the negative electrode ISO_GND of the battery pack. Of course, during the acquisition process, the duration of the voltage value input to the controller can be determined when the sampling control signal is continuously output. Finally, the voltage difference between the two sides of the relay is determined according to the difference in the voltage values ​​collected on both sides of the relay, and then the duration of the voltage difference is recorded while the voltage difference between the two sides of the relay remains unchanged. Taking the 400V battery pack system as an example, the second resistor R2 is generally composed of 6 510K sampling resistors in series, and the third resistor R3 takes a value of 30K; when the voltage value V_HV1 of the first sampling point is 400V, the sampling voltage sent to the vehicle controller is 400÷(R2+R3)*R3=3.883V; when the voltage value of the first sampling point is 360V, the sampling voltage sent to the vehicle controller is 360÷(R2+R3)*R3=3.495V; when the interference point 1, the high-voltage source has electromagnetic interference of more than 40V, and it is detected 10 times continuously (once every 10ms), it is determined that the relay is melted; or when the interference point 2, the sampling point voltage divider circuit has a voltage fluctuation of 0.388V=(3.883V-3.495V), it is detected 10 times continuously (once every 10ms), it is determined that the relay is melted.

[0062] Step S20: When the voltage difference is greater than a preset voltage difference threshold and the duration reaches a preset duration threshold, control the battery pack to enter a low-power cooling charging state.

[0063] It should be noted that the low-power cooling charging state is a charging state in which the charging power is less than the rated charging power and the battery pack cooling system is turned on. Compared with the normal charging mode of fast charging, the low-power cooling charging state has a certain decrease in charging power, and the battery pack cooling system in the vehicle is turned on. In the presence of electromagnetic interference, by reducing the charging power and turning on the cooling system, the overvoltage or overtemperature of the battery pack caused by electromagnetic interference during the charging process can be effectively avoided. The preset voltage difference threshold is a voltage difference threshold preset for determining whether the relay is melted. The duration is a duration threshold preset for determining whether the relay is melted. When the voltage difference is greater than the preset voltage difference threshold and the duration of the voltage difference reaches the preset duration threshold, it can usually be determined that the relay is melted. However, in the actual determination process, it is also necessary to consider the external electromagnetic interference. In the case where the relay is not melted, the electromagnetic interference may also cause the voltage difference across the relay to be greater than the preset voltage difference threshold, and the duration reaches the preset duration threshold.

[0064] It is understandable that, in the case of a relay melting, even if the charging power is reduced and the cooling system is turned on, the battery pack charging process will still be abnormal, such as the battery pack charging voltage being overvoltage or the battery pack being overheated. However, in the case of a relay not melting, the voltage difference between the two ends of the relay caused by electromagnetic interference is greater than the preset voltage difference threshold, and the duration reaches the preset duration threshold, and the battery pack will not be overvoltage and / or overheated due to the decrease in charging power and the activation of the cooling system.

[0065] In a specific implementation, when it is determined that the voltage difference on both sides of the relay is greater than a preset voltage difference threshold and the duration reaches a preset duration threshold, the battery pack can be controlled to enter a low-power cooling charging state by reducing the charging power and turning on the cooling system of the battery pack.

[0066] Step S30: In the low-power cooling charging state, detecting whether the battery pack has overvoltage and / or overtemperature.

[0067] It should be understood that when the battery pack is in a low-power cooling charging state, by detecting whether the battery pack has overvoltage and / or overtemperature during the process, it can be determined that the voltage difference is greater than the preset voltage difference threshold, and whether the duration reaches the preset duration threshold due to electromagnetic interference or due to an abnormality of the charging pile.

[0068] Therefore, in the low-power cooling charging state, by detecting whether the battery pack is over-voltage and over-temperature, the specific reasons why the voltage difference on both sides of the relay is greater than the preset voltage difference threshold and the duration reaches the preset duration threshold are determined.

[0069] In the specific detection process, the charging voltage of the battery pack can be detected in a low-power cooling charging state, and the temperature of the battery pack can be detected. The charging voltage is then compared with the maximum acceptable charging voltage of the battery pack under normal charging conditions, and the temperature of the battery pack during the charging process is compared with the maximum acceptable temperature of the battery pack under normal charging conditions, so as to determine whether the battery pack will send overvoltage and / or overtemperature conditions in the low-power cooling charging state.

[0070] Step S40: If not, the parameter information of the charging pile is sent to the cloud, and the status of the charging pile is determined through the cloud.

[0071] It is understandable that when the battery pack is charged in a low-power cooling charging state, if the battery pack has at least one of overvoltage or overtemperature, it can be determined that the relay is melted due to a fault in the charging pile, and the battery pack needs to be stopped from charging. Of course, when the battery pack is charged in a low-power cooling charging state, if the battery pack does not have any of overvoltage or overtemperature, it can be preliminarily determined that the cause of the abnormal detection relay is electromagnetic interference.

[0072] In order to more accurately determine whether the charging pile has a fault, the status of the charging pile can also be determined through the cloud. The charging pile status includes a fault state and a non-fault state. In the fault state, the charging pile charges the battery pack, which may cause abnormalities such as melting of the relay.

[0073] It should be noted that the parameter information of the charging pile includes the unique identification information of the charging status, through which the cloud can directly query the charging pile. Of course, the parameter information may also include other information, such as the historical charging information of the charging pile, charging voltage, charging power, etc.

[0074] When it is preliminarily determined that the voltage difference between the two ends of the relay is too large and lasts for a long time due to electromagnetic interference, the parameter information of the charging pile can also be sent to the cloud. The cloud can determine whether the charging pile has a fault based on the parameter information of the charging pile. For example, the cloud can determine whether the charging pile has a fault based on the historical charging information of the charging pile. The cloud records that the charging pile had a fault during the previous charging. For example, the status of the charging pile can be determined by measures such as whether the charging voltage and charging power output by the charging pile match the charging voltage and charging power actually required by the charging pile.

[0075] Step S50: When the charging pile is in a non-fault state, control the charging pile to charge the battery pack.

[0076] It should be understood that after the cloud determines the status of the charging pile, it can feed back the determined status of the charging pile to the vehicle side. When the vehicle side determines that the status of the charging pile is in a non-fault state, it can be determined that the charging pile has not failed and the relay has not melted, and the charging pile can be directly controlled to charge the battery pack. Of course, when the status of the charging pile fed back by the cloud is a faulty state, the relay may melt and it is necessary to stop charging the battery pack. In the process of controlling the charging pile to charge the battery pack, the current low-power cooling charging state can be maintained, or the low-power cooling charging state can be switched to a normal charging state.

[0077] This embodiment provides a charging control method, which detects the voltage difference between the two ends of the relay and the duration of the voltage difference when the battery pack is charged; when the voltage difference is greater than a preset voltage difference threshold and the duration reaches a preset duration threshold, the battery pack is controlled to enter a low-power cooling charging state, wherein the low-power cooling charging state is a charging state in which the charging power is less than the rated charging power and the battery pack cooling system is turned on; in the low-power cooling charging state, the battery pack is detected to be over-voltage and / or over-temperature; if not, the parameter information of the charging pile is sent to the cloud, and the charging pile status is determined through the cloud; when the charging pile status is a non-fault state, the charging pile is controlled to charge the battery pack. In this embodiment, when the voltage difference between the two ends of the relay and the duration threshold exceed the standard, the battery pack is controlled to enter a low-power cooling charging state to detect whether the battery pack is over-voltage or over-temperature, and the charging pile status is determined by using the cloud to determine whether the threshold exceeds the standard due to electromagnetic interference or charging pile failure, and then when the charging pile is in a non-fault state, the charging pile is controlled to charge the battery pack.

[0078] Based on the first embodiment of the charging control method described above, a second embodiment of the charging control method of the present invention is proposed. Figure 4 , Figure 4 This is a schematic diagram of a first flow chart of a second embodiment of a charging control method provided by the present invention.

[0079] In this embodiment, before step S10, the following steps are also included:

[0080] Step S11: Obtain parameter information of the charging pile.

[0081] It should be understood that the parameter information of the charging pile may include the unique identification information of the charging pile, the operation information of the charging pile, and the historical information of the charging pile, etc. The parameter information set for different charging piles is not the same. For example, in order to determine a specific charging pile, the unique identification information in the charging pile parameter information may be used. The unique identification information may be the hardware serial number of the charging pile, the location coordinate information of the charging pile, etc.

[0082] In a specific implementation, the vehicle can directly interact with the charging pile to extract parameter information in the charging pile when establishing a connection with the charging pile. Of course, before the charging pile charges the vehicle, when there is interaction between the vehicle and the charging pile, the charging pile can also directly output the collected parameter information to the vehicle.

[0083] Step S12: extracting a preset voltage difference threshold and a preset duration threshold corresponding to the charging pile according to the parameter information.

[0084] It is understandable that in the parameter information of the charging pile, the voltage difference range on both sides of the relay when the charging pile is charging the battery pack can be directly extracted, and the maximum value in the voltage difference range can be used as the preset voltage threshold. In order to avoid errors, it is also necessary to determine the preset duration threshold corresponding to the preset voltage difference threshold. In addition, the charging voltage threshold output by the charging pile can be extracted through parameter information, and then the preset voltage difference threshold that may be formed by the charging voltage threshold on both sides of the relay can be determined according to the specific charging system.

[0085] Reference Figure 5 , Figure 5 This is a second flow chart of the second embodiment of the charging control method proposed by the present invention. In this embodiment, after step S50, the method further includes:

[0086] Step S51: When the battery pack is being charged, a voltage difference set at both sides of the relay and a duration corresponding to each voltage difference in the voltage difference set are detected.

[0087] It should be understood that during the charging process of the battery pack, it is subject to external electromagnetic interference. Considering that electromagnetic interference with high interference intensity and long interference time is usually interference sources such as TV towers, radar stations, and substations near the charging pile. The location of this part of the interference source is relatively fixed to the location of the charging pile, and the electromagnetic interference intensity is relatively large. In the subsequent charging process, the previously set preset voltage difference threshold and preset duration threshold are used to repeatedly diagnose whether the relay is abnormal. In order to avoid the situation that the vehicle end needs to repeatedly detect the voltage difference between the two sides of the relay is greater than the preset voltage difference threshold each time the charging pile charges the battery pack in the vehicle, and the duration reaches the preset duration threshold, during the charging process of the battery pack, the voltage difference between the two sides of the relay can be continuously collected, and the duration of each voltage difference can be recorded, so that the next time the charging pile charges the battery pack, the actual voltage difference and the corresponding duration can be used to detect whether the relay is melted during the charging process.

[0088] It should be noted that the voltage difference set on both sides of the relay refers to the set of all voltage differences on both sides of the collector when the charging pile is charging the battery pack. The duration corresponding to each voltage difference is the maximum duration of each voltage difference on both sides of the relay during the time when it does not change. For example, during the charging process, the voltage difference on both sides of the relay can fluctuate within 40V. When the voltage difference reaches 30V twice, the duration of the two voltage differences of 30V can be recorded, and the longer duration can be selected as the maximum duration.

[0089] In a specific implementation, when the charging pile is charging the battery pack, the voltage difference on both sides of the relay can be monitored in real time, and the duration corresponding to different voltage differences can be recorded.

[0090] Step S52: updating the preset voltage difference threshold and the preset duration threshold in the parameter information according to the maximum voltage difference in the voltage difference set and the maximum duration corresponding to the maximum voltage difference.

[0091] It is understandable that during the battery pack charging process, the voltage difference between the two sides of the relay is an acceptable voltage difference during normal charging. By recording the voltage difference set, the voltage difference and the corresponding duration can be selected from the set as a new preset voltage difference threshold and a corresponding preset duration threshold.

[0092] When determining specifically, the maximum voltage difference in the voltage difference set collected in the battery pack can be used as the latest preset voltage difference threshold, and then the maximum duration corresponding to the maximum voltage difference can be used as the preset duration threshold of the information. The next time the charging pile charges the battery pack, the preset voltage difference threshold and the preset duration threshold in the updated parameter information can be directly used as the threshold for determining whether the relay is melted.

[0093] Step S53: sending the new preset voltage difference threshold and the preset time threshold to the cloud for storage.

[0094] It should be understood that the cloud can control the charging process of multiple charging piles and interact with information between multiple vehicle terminals. The voltage difference and duration on both sides of the relay during the relay detection process can be stored in the cloud. When different parameter information is provided on the vehicle side, the cloud can determine the charging pile status corresponding to the parameter information. Of course, when the vehicle needs to be charged, the vehicle side can be provided with information such as the status of the charging piles near the vehicle and the differences in electromagnetic interference between different charging piles.

[0095] In a specific implementation, the vehicle side can upload updated parameter information to the cloud, and the parameter information includes a new preset voltage difference threshold and a preset time threshold. The cloud can receive parameter information of charging piles in a certain area or a certain number of charging piles.

[0096] Step S54: sorting the interference levels of the charging piles according to the new preset voltage difference threshold and the preset time threshold through the cloud to obtain the interference level of the charging piles.

[0097] It is understandable that, considering that the locations of different charging piles are not the same, the electromagnetic interference received by the charging piles may be different. The cloud can determine the interference received by each charging pile based on the parameter information of different charging piles uploaded by the vehicle.

[0098] It should be noted that the interference level refers to the specific interference situation of different charging piles subjected to external electromagnetic interference. The electromagnetic interference corresponding to different interference levels is not the same. For example, for charging piles near the same electronic factory, the closer the charging pile is to the electronic factory, the greater the electromagnetic interference it is subjected to, and the stronger the corresponding interference level. The voltage difference generated by electromagnetic interference can be used as the basis for determining the specific interference level; for example, when the voltage difference generated by electromagnetic interference reaches 5% of the preset voltage difference threshold, it can be identified as first-level interference; when the voltage difference generated by electromagnetic interference reaches 10% of the preset voltage difference threshold, it can be identified as second-level interference; when the voltage difference generated by electromagnetic interference reaches 15% of the preset voltage difference threshold, it can be identified as third-level interference, and so on. In addition, the duration corresponding to the voltage difference can also be used as the basis for determining the specific interference level; for example, when the duration of electromagnetic interference reaches 5% of the preset duration threshold, it can be identified as first-level interference; when the duration of electromagnetic interference reaches 10% of the preset duration threshold, it can be identified as second-level interference; when the duration of electromagnetic interference reaches 15% of the preset duration threshold, it can be identified as third-level interference, and so on.

[0099] In a specific implementation, the interference conditions of different charging piles can be sorted according to the preset voltage difference threshold and the preset time threshold in the parameter information of different charging piles, and then the interference levels of different charging states can be sorted to obtain the interference levels of different charging piles.

[0100] Step S55: When a charging demand is detected, the interference level of each charging pile is output through the cloud.

[0101] It is understandable that when the vehicle's battery pack has a charging demand, the cloud can output the interference level of all charging piles near the vehicle. The charging demand can be input by the user to the vehicle side; or the vehicle side can directly detect the remaining power of the battery pack and directly generate a charging demand when the remaining power of the battery pack is low.

[0102] It should be noted that when there is a demand for charging, the cloud can output the interference level of the charging piles near the vehicle. When the vehicle or the user's terminal receives the interference level, the user can select a charging pile with a lower interference level based on the interference level of the charging pile received.

[0103] Step S56: Detect whether the user has replaced the charging pile.

[0104] It is understandable that when the cloud outputs the interference level, the vehicle side can select a different charging pile for the vehicle battery pack according to the interference level prompt received by the user. If the battery pack on the vehicle side is in the charging process, when the user receives the prompt corresponding to the interference level, he can select the charging pile with a lower interference level. Of course, if the charging pile can be used for normal charging, the charging pile does not need to be changed.

[0105] In a specific implementation, the vehicle side can output a prompt corresponding to the interference level in the cloud, and then ask the user whether to change the charging pile when selecting the charging pile or during the charging process. Whether the user changes the charging pile can be determined by whether the charging pile selected by the user changes; whether the connection between the charging interface and the discharge gun is disconnected during the battery pack charging process to determine whether the user changes the charging pile; and whether the user changes the charging pile according to whether the parameter information of the charging pile connected to the vehicle side changes.

[0106] Step S57: If not, return to the step of controlling the battery pack to enter a low-power cooling charging state.

[0107] It is understandable that when it is determined that the user has not replaced the charging pile, in order to ensure the safety of charging, the relay is tested for melting. However, since it is still impossible to determine whether the charging pile itself is abnormal when it is determined that there is electromagnetic interference in the charging pile, it is still necessary to control the battery pack to enter a low-power cooling charging state to further determine whether the charging pile is abnormal. Of course, if the user chooses to change the charging state, the voltage difference on both sides of the relay and the duration of the voltage difference can be detected according to the specific interference level of the charging pile.

[0108] Reference Figure 6 , Figure 6 The third embodiment of the charging control method of the present invention is a flow chart of the third embodiment of the charging control method of the present invention. The third embodiment of the charging control method of the present invention is proposed based on the first embodiment or the second embodiment of the charging control method.

[0109] In this embodiment, before step S40, the following steps are also included:

[0110] Step S41: determining interference source information according to the parameter information and the vehicle map.

[0111] It should be noted that the car map is a map stored in the car, which can be updated in real time. The interference source information refers to the information of the source of electromagnetic interference to the charging pile near the vehicle, which can be a high-voltage substation, TV tower, radar station, etc.

[0112] Considering the influence of interference sources on the charging voltage output by the charging pile, as well as the strength of the interference source and the distance between the interference source and the charging pile. For example, when there is a high-voltage substation near the charging pile, the specific power intensity of the high-voltage substation output and the distance between the high-voltage substation and the charging pile will affect the charging voltage output by the charging pile. In the process of determining the status of the charging pile, the interference source information can also be combined to more accurately determine the status of the charging pile.

[0113] In a specific implementation, the vehicle side can determine the location of the charging pile based on the parameter information of the charging pile, and then use the vehicle map and the location of the charging pile to determine the interference source information near the charging pile. For example, the vehicle side can record the specific location of each interference source such as a high-voltage substation on the vehicle map based on the location information of the charging pile, and determine the electromagnetic interference intensity of each interference source based on the power output of each interference source.

[0114] Accordingly, the step S40 specifically includes:

[0115] Step S401: Send the parameter information and the interference source information to the cloud.

[0116] Step S402: extracting historical fault information of the charging pile according to the parameter information through the cloud, and determining the state of the charging pile according to the historical fault information and the interference source information.

[0117] It should be understood that when the vehicle side determines the parameter information of the charging pile and the interference source information near the charging pile, the parameter information and the interference source information can be directly sent to the remote end. When the cloud receives the parameter information and the interference source information, it can directly extract the unique identification information of the charging pile from the parameter information based on the parameter information, and then extract the historical fault information of the charging pile based on the unique identification information; according to the historical fault information, it can be determined whether the charging pile is in a faulty state. For example, when the previous vehicle is charging, the cloud can record whether the charging pile has a fault; when the previous vehicle is charging, when the cloud determines that the charging pile is in a faulty state, it can be determined that the charging pile is in a faulty state during this charging process. Of course, when there is a record related to the maintenance of the charging pile between the two chargings, the charging pile can be determined to be in a non-faulty state. In addition, the cloud can also determine the possible interference to the charging pile based on the interference source information, which will cause the impact of the charging pile output charging voltage. For example, when the charging pile normally outputs a voltage value of 400V, since the interference source information may cause a voltage change within 40V, if the charging voltage in the parameter information is between 360V and 440V, it can be determined that the charging pile is not in a faulty state; if the charging voltage is greater than 440V, it can be determined that the change in the charging voltage output by the charging pile is not only caused by the interference source, that is, there is a fault in the charging pile.

[0118] It should be noted that the historical fault information is the information stored in the cloud before the current charging whether the charging pile is in a fault state. In a specific implementation, when the cloud receives the parameter information and the interference source information, it can directly determine whether the charging pile is in a fault state based on the historical fault information and the interference source information in the parameter information.

[0119] In this embodiment, the state of the charging pile can be determined more accurately through the interference source information near the charging pile and the parameter information of the charging source.

[0120] Reference Figure 7 , Figure 7 The third embodiment of the charging control method of the present invention is proposed based on any one of the first to third embodiments of the charging control method.

[0121] In this embodiment, step S20 includes:

[0122] Step S201: when the voltage difference is greater than a preset voltage difference threshold and the duration reaches a preset duration threshold, start pre-charging the battery pack.

[0123] It should be noted that battery pack pre-charging is the process of charging the battery pack using a branch with a series pre-charging resistor. During the battery pack pre-charging process, the current of the pre-charging process is low due to the presence of the pre-charging resistor. During the battery pack pre-charging process, the battery pack usually does not have abnormalities such as overvoltage or overtemperature. Therefore, during the battery pack pre-charging process, it is possible to detect whether the battery pack has overvoltage, overtemperature, etc. If any of these occurs, it indicates that the pre-charging process cannot charge the battery pack normally, and the charging pile fails. At this time, the relay needs to be disconnected in time to avoid affecting the components and battery pack in the charging system.

[0124] In a specific implementation, during relay detection, when the voltage difference on both sides of the relay is greater than a preset voltage difference threshold and the duration reaches a preset duration threshold, the charging pile can be started to pre-charge the battery pack. Then, during the pre-charging process of the battery pack, the battery pack can be detected to see whether it will have abnormalities such as overvoltage or overtemperature.

[0125] Step S202: When the pre-charging of the battery pack is completed, control the battery pack to enter a low-power cooling charging state.

[0126] It is understandable that when no abnormal conditions such as overtemperature or overvoltage occur during the pre-charging process of the battery pack, the pre-charging of the battery pack will continue until the pre-charging of the battery pack is completed. The probability of abnormal conditions such as overvoltage or overtemperature occurring during the pre-charging process of the battery pack is very low due to the small pre-charging current, unless the charging pile fails or the electromagnetic interference is too large. When the pre-charging is completed, considering that the voltage difference on both sides of the relay is greater than the preset voltage difference threshold, and the duration reaches the preset duration threshold, it may be due to electromagnetic interference and the charging pile state is in a fault state. The process of further determining whether the charging pile state is in a fault state can be performed by reducing the charging power and turning on the cooling system.

[0127] Wherein, the step S201 specifically includes:

[0128] Step S2011: Detect whether the voltage difference is greater than an upper threshold voltage and whether the duration corresponding to the voltage difference reaches an upper threshold duration.

[0129] It is understandable that in the presence of electromagnetic interference, if the electromagnetic interference is small, although it will cause the voltage difference on both sides of the relay to be greater than the preset voltage difference threshold, and the duration reaches the preset duration threshold, it will not affect the charging process of the battery pack. However, if the electromagnetic interference is too large, it may cause the charging voltage to be greater than the charging voltage that the charging system or battery pack can bear. For example, when the normal charging voltage is 400V, due to the large electromagnetic interference, the charging voltage is disturbed to 500V, and the 500V charging voltage will also cause abnormalities to the charging system of the battery pack.

[0130] It should be noted that the upper threshold voltage is the maximum charging voltage value that the charging system and the battery pack can bear. The upper threshold duration is the maximum duration that the charging system and the battery pack can bear. If the voltage difference across the relay is greater than the upper threshold voltage or the duration reaches the upper threshold duration, whether it is a charging pile failure or electromagnetic interference, the relay needs to be disconnected to avoid causing abnormalities in the device or battery pack.

[0131] In this embodiment, the voltage difference between the two sides of the relay may be compared with the upper threshold voltage, and then the duration of the voltage difference between the two sides of the relay may be compared with the upper threshold duration.

[0132] Step S2012: when the voltage difference is not greater than the upper threshold voltage, or when the voltage difference is greater than the upper threshold voltage but the duration of the voltage difference does not reach the upper threshold duration, start pre-charging the battery pack.

[0133] It is understandable that when the voltage difference on both sides of the relay is not greater than the upper threshold voltage, although there is electromagnetic interference, this part of the electromagnetic interference will not have a significant impact on the charging of the battery pack, and the battery pack can still be charged normally. The voltage difference is greater than the upper threshold voltage but the threshold duration does not reach the upper threshold duration. This process is only a short-term excessive voltage difference, and it will not have a significant impact on the charging of the battery pack. At this time, the battery pack can still be charged. However, when the voltage difference on both sides of the relay is greater than the upper threshold voltage, and the threshold duration reaches the upper threshold duration, it can be determined that the electromagnetic interference is too large and the duration of the interference is too long, which will affect the charging of the battery pack. At this time, the relay needs to be disconnected in time.

[0134] In this embodiment, by checking whether the voltage difference between the two sides of the relay is greater than the upper threshold voltage and whether the duration of the voltage difference is greater than the upper threshold duration, it is determined whether the battery pack can be charged before starting charging. In addition, during the pre-charging process, by checking whether the battery pack will have overvoltage or overtemperature abnormalities, the charging process of the battery pack can be controlled more accurately.

[0135] In addition, to achieve the above-mentioned purpose, the present invention also provides a vehicle, in which the above-mentioned converter is arranged, and the heating controller arranged in the converter is used to execute the charging control method in any of the above-mentioned embodiments.

[0136] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A charging control method, characterized in that: The charging control method comprises: When the battery pack is charged, detecting a voltage difference across the relay and a duration of the voltage difference; When the voltage difference is greater than a preset voltage difference threshold and the duration reaches a preset duration threshold, the battery pack is controlled to enter a low-power cooling charging state, where the low-power cooling charging state is a charging state in which the charging power is less than the rated charging power and the battery pack cooling system is turned on; In the low-power cooling charging state, detecting whether the battery pack has overvoltage and / or overtemperature; If not, the parameter information of the charging pile is sent to the cloud, and the charging pile status is determined through the cloud; When the charging pile is in a non-fault state, the charging pile is controlled to charge the battery pack.

2. The charging control method according to claim 1, characterized in that: During the battery pack charging process, before detecting the voltage difference across the relay and the duration of the voltage difference, the method further includes: Get the parameter information of the charging pile; The preset voltage difference threshold and the preset time threshold corresponding to the charging pile are extracted according to the parameter information.

3. The charging control method according to claim 2, characterized in that: When the charging pile is in a non-fault state, after controlling the charging pile to charge the battery pack, the method further includes: When the battery pack is charged, detecting a voltage difference set at both sides of the relay and a duration corresponding to each voltage difference in the voltage difference set; The preset voltage difference threshold and the preset duration threshold in the parameter information are updated according to the maximum voltage difference in the voltage difference set and the maximum duration corresponding to the maximum voltage difference.

4. The charging control method according to claim 3, characterized in that: After the preset voltage difference threshold and the preset duration threshold in the parameter information are updated by using the maximum voltage difference in the voltage difference set and the maximum duration corresponding to the maximum voltage difference, the method further includes: Sending the new preset voltage difference threshold and the preset time threshold to the cloud for storage; The interference level of each charging pile is obtained by sorting the interference level of each charging pile according to the new preset voltage difference threshold and the preset time threshold through the cloud; When a charging demand is detected, the interference level of each charging pile is output through the cloud.

5. The charging control method according to claim 4, characterized in that: When the charging demand is detected, after the interference level of each charging pile is output through the cloud, the method further includes: Detect whether the user has changed the charging pile; If not, return to the step of controlling the battery pack to enter a low-power cooling charging state.

6. The charging control method according to claim 1, characterized in that: Before sending the parameter information of the charging pile to the cloud and judging the status of the charging pile through the cloud, the method further includes: Determine interference source information according to the parameter information and the vehicle map; The step of sending the parameter information of the charging pile to the cloud and determining the status of the charging pile through the cloud includes: Sending the parameter information and the interference source information to the cloud; The cloud extracts historical fault information of the charging pile according to the parameter information, and determines the state of the charging pile according to the historical fault information and the interference source information.

7. The charging control method according to claim 1, characterized in that: When the voltage difference is greater than a preset voltage difference threshold and the duration reaches a preset duration threshold, controlling the battery pack to enter a low-power cooling charging state includes: When the voltage difference is greater than a preset voltage difference threshold and the duration reaches a preset duration threshold, starting the pre-charging of the battery pack; When the pre-charging of the battery pack is completed, the battery pack is controlled to enter a low-power cooling charging state.

8. The charging control method according to claim 7, characterized in that: When the voltage difference is greater than a preset voltage difference threshold and the duration reaches a preset duration threshold, starting the pre-charging of the battery pack includes: Detecting whether the voltage difference is greater than an upper threshold voltage and whether a duration corresponding to the voltage difference reaches an upper threshold duration; When the voltage difference is not greater than the upper threshold voltage, or when the voltage difference is greater than the upper threshold voltage but the threshold duration does not reach the upper threshold duration, the battery pack pre-charging is started.

9. A charging system, characterized in that: The charging system includes: a controller, a fast charging branch and a slow charging branch, the fast charging branch is connected to the fast charging interface and the battery pack respectively, and the slow charging branch is connected to the slow charging interface and the battery pack respectively; the controller is connected to the relays in the fast charging branch and the slow charging branch; the controller is used to execute the charging control method described in any one of claims 1-8.

10. A vehicle, characterized in that: The vehicle comprises: the charging system according to claim 9.

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