Electric vehicle fast charging relay adhesion detection method, system and device and storage medium

Abstract

The invention discloses an electric vehicle fast charging relay adhesion detection method, system and device and a storage medium, adhesion detection of a fast charging positive relay and a fast charging negative relay can be completed in real time at the charging end stage, and a user does not need to wait for high-voltage power-on operation. Only one-time adhesion detection is ensured in one charging cycle through detection implementation resumes, excessive loss of hardware caused by repeated detection is avoided, and high-voltage power-off and serious risk prompting are carried out when adhesion is detected by positive and negative relays at the same time. Through the design of the relay adhesion detection circuit, the influence of the residual voltage of the charging pile on the detection accuracy can be eliminated, the adhesion false alarm is avoided, the timeliness, comprehensiveness and reliability of the adhesion detection of the fast charging relay are improved, and the method can be applied to the technical field of vehicle detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle detection, and in particular to a method, system and device for detecting adhesion of a fast-charging relay of an electric vehicle, and a storage medium. BACKGROUND

[0002] The DC charging process of an electric vehicle includes inserting a DC charging gun into a DC input socket of the electric vehicle and controlling a fast-charging relay of a power battery to be closed by a vehicle controller, so as to form a charging loop. After the charging is completed, the fast-charging relay needs to be controlled to be opened by the vehicle controller. However, the fast-charging relay may be stuck during use, causing the vehicle controller to be unable to control the fast-charging relay to be opened after the charging is completed. This makes the charging port of the electric vehicle be electrified after the vehicle is powered on, which poses a high-voltage safety risk. Therefore, the adhesion detection of the fast-charging relay is crucial for the electric vehicle.

[0003] In related technologies, only the adhesion state of the positive fast-charging relay can be detected in CN115267519A-A method for detecting adhesion of a fast-charging relay of an electric vehicle, and the adhesion state of the negative fast-charging relay cannot be detected simultaneously. Although CN117590214A-A method and system for detecting adhesion of a fast-charging relay of an electric vehicle can detect the adhesion states of the positive / negative fast-charging relays simultaneously, it cannot detect in time at the end of the charging stage, and the adhesion of the positive / negative fast-charging relays can only be detected when the vehicle is powered on again at high voltage after the charging stage ends. In addition, after the adhesion of the positive / negative fast-charging relays is detected simultaneously, there is a lack of high-voltage power-off safety protection. Furthermore, the system can only detect the voltage difference between the positive end of the fast-charging port and the negative end of the battery, and cannot detect the real voltage of the fast-charging pile. CN113533948A-A method, device, equipment and automobile for detecting faults of a fast-charging relay and CN113884871A-A method, device, equipment and storage medium for detecting states of a relay focus on the overall process of detecting the state of the fast-charging relay, and do not explicitly show the specific process of judging the adhesion of the relay.

[0004] In summary, the existing adhesion detection schemes for the fast-charging relay of the electric vehicle have the following shortcomings:

[0005] 1) Only the adhesion state of the positive fast-charging relay can be detected, and the adhesion state of the negative fast-charging relay cannot be detected simultaneously. If the positive and negative fast-charging relays are stuck simultaneously, there is a safety risk.

[0006] 2) The adhesion cannot be detected at the end of the charging stage, and can only be detected when the vehicle is powered on again at high voltage. If the vehicle is still in a high-voltage state after the fast-charging is completed, the adhesion cannot be detected because it is not the detection time, which poses a safety risk.

[0007] 3) After the adhesion of the positive / negative fast-charging relays is detected simultaneously, there is a lack of prompt of major safety risks and a mechanism for emergency high-voltage power-off, which cannot provide physical safety protection for the user.

[0008] 4) Relay adhesion detection is required every time high voltage is powered on. Repeated and excessive detection will affect the operating life of the relay;

[0009] 5) The adhesion detection of the fast charging positive / negative relay is easily affected by the residual voltage of the charging pile, causing false adhesion alarms and causing trouble for users. Summary of the Invention

[0010] The purpose of the present invention is to solve one of the technical problems existing in the prior art to at least a certain extent.

[0011] To this end, an object of an embodiment of the present invention is to provide a method for detecting adhesion of fast-charging relays of electric vehicles. This method can complete the adhesion detection of fast-charging positive relays and negative relays in real time at the end of charging, without waiting for the user to perform high-voltage power-on operation, and only performs one adhesion detection in a charging cycle to avoid excessive damage to hardware due to repeated detection. When the positive and negative relays detect adhesion at the same time, high-voltage power is cut off and serious risk prompts are issued. In addition, the influence of the residual voltage of the charging pile on the detection accuracy can be eliminated, false adhesion alarms can be avoided, and the timeliness, comprehensiveness and reliability of fast-charging relay adhesion detection are improved.

[0012] Another object of an embodiment of the present invention is to provide an electric vehicle fast charging relay adhesion detection system.

[0013] In order to achieve the above technical objectives, the technical solutions adopted by the embodiments of the present invention include:

[0014] In a first aspect, an embodiment of the present invention provides a method for detecting adhesion of an electric vehicle fast charging relay, comprising the following steps:

[0015] In response to the fast charge relay disconnection instruction, the battery management system drives the fast charge positive relay and the fast charge negative relay to disconnect;

[0016] Control the first switch of the relay adhesion detection circuit to be closed and the second switch to be open, obtain a first sampling voltage at a first sampling point and a second sampling voltage at a second sampling point, and determine whether the fast charging positive relay is adhered based on the first sampling voltage and the second sampling voltage;

[0017] Controlling the first switch of the relay adhesion detection circuit to be open and the second switch to be closed, obtaining a third sampling voltage at a third sampling point, and determining whether the fast charging negative relay is adhered according to the third sampling voltage;

[0018] When the fast charging positive relay or the fast charging negative relay is stuck, a general risk warning message is generated;

[0019] When the fast charging positive relay and the fast charging negative relay are both stuck, the battery management system is used to perform high-voltage power-off, and a serious risk prompt information is generated;

[0020] The relay sticking detection circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first switch, a second switch, a first diode, a first voltage source, a first sampling point, a second sampling point, and a third sampling point. One end of the first resistor is connected between the fast charging port positive end and the fast charging positive relay. One end of the third resistor is connected between the high-voltage battery positive end and the fast charging positive relay. One end of the second resistor, one end of the fourth resistor, and one end of the sixth resistor are all connected between the high-voltage battery negative end and the fast charging negative relay. One end of the seventh resistor is connected between the fast charging port negative end and the fast charging negative relay. One end of the fifth resistor and the negative electrode of the first diode are connected to the first voltage source. The other end of the first resistor is connected to the other end of the second resistor through the first switch. The other end of the third resistor is connected to the other end of the fourth resistor. The other end of the fifth resistor, the other end of the sixth resistor, and the positive electrode of the first diode are all connected to the other end of the seventh resistor through the second switch. The first sampling point is located between the third resistor and the fourth resistor. The second sampling point is located between the first resistor and the second resistor. The third sampling point is located between the sixth resistor and the second switch.

[0021] Further, in an embodiment of the present application, the resistance ratio of the first resistor and the second resistor is equal to the resistance ratio of the third resistor and the fourth resistor. The determination of whether the fast charging positive relay is stuck according to the first sampling voltage and the second sampling voltage specifically comprises:

[0022] calculating the absolute value of the voltage difference between the first sampling voltage and the second sampling voltage;

[0023] when the absolute value of the voltage difference is greater than a preset positive sticking threshold, determining that the fast charging positive relay is not stuck;

[0024] when the absolute value of the voltage difference is less than or equal to the positive sticking threshold, determining that the fast charging positive relay is stuck.

[0025] Further, in an embodiment of the present application, the first sampling voltage is obtained by a first voltage sensor, and the second sampling voltage is obtained by a second voltage sensor. The positive sticking threshold is determined by the following steps:

[0026] determining a first positive error and a first negative error of the first voltage sensor;

[0027] determining a second positive error and a second negative error of the second voltage sensor;

[0028] determining a first error threshold according to a difference between the first positive error and the second negative error, and determining a second error threshold according to a difference between the second positive error and the second negative error;

[0029] selecting a maximum value between the first error threshold and the second error threshold as the positive adhesion threshold.

[0030] Further, in an embodiment of the present application, the determining whether the fast charging negative relay adheres according to the third sampling voltage specifically comprises:

[0031] when the third sampling voltage is greater than or equal to a preset negative adhesion threshold, determining that the fast charging negative relay does not adhere;

[0032] when the third sampling voltage is less than the negative adhesion threshold, determining that the fast charging negative relay adheres.

[0033] Further, in an embodiment of the present application, the third sampling voltage is obtained by a third voltage sensor, and the negative adhesion threshold is determined by the following formula:

[0034]

[0035] wherein, V 负 represents the negative adhesion threshold, R5 represents a resistance value of the fifth resistor, R6 represents a resistance value of the sixth resistor, R7 represents a resistance value of the seventh resistor, U represents a voltage value of the first voltage source, represents a third positive error of the third voltage sensor, represents a third negative error of the third voltage sensor.

[0036] Further, in an embodiment of the present application, the executing high-voltage power-off by the battery management system and generating a serious risk prompt information specifically comprises:

[0037] determining whether the vehicle speed is 0 and whether the vehicle is in P gear;

[0038] when the vehicle speed is 0 and the vehicle is in P gear, executing high-voltage power-off by the battery management system, generating a serious risk prompt information and pushing to the user;

[0039] when the vehicle speed is not 0 and / or the vehicle is not in P gear, generating a serious risk prompt information and playing in the vehicle, and then executing high-voltage power-off by the battery management system after the vehicle speed is reduced to 0 and / or the vehicle is shifted to P gear.

[0040] Further, in one embodiment of the present application, the electric vehicle fast charging relay sticking detection method further comprises the following steps:

[0041] After judging whether the fast charging positive relay and the fast charging negative relay stick, setting the relay sticking detection implementation history of the vehicle to a detected state;

[0042] When the vehicle enters the next charging cycle and the battery management system drives the fast charging positive relay and the fast charging negative relay to close, setting the relay sticking detection implementation history to an undetected state;

[0043] The relay sticking detection implementation history is used to determine whether to perform the sticking detection of the fast charging positive relay and the fast charging negative relay. When the relay sticking detection implementation history is in the detected state, the sticking detection of the fast charging positive relay and the fast charging negative relay is no longer repeated. When the relay sticking detection implementation history is in the undetected state, the sticking detection of the fast charging positive relay and the fast charging negative relay is performed after the fast charging positive relay and the fast charging negative relay are driven to open by the battery management system.

[0044] In a second aspect, an embodiment of the present application provides an electric vehicle fast charging relay sticking detection system, comprising:

[0045] A relay driving module is configured to drive the fast charging positive relay and the fast charging negative relay to open by the battery management system in response to a fast charging relay opening instruction;

[0046] A positive relay sticking detection module is configured to control the first switch of the relay sticking detection circuit to close and the second switch to open, acquire the first sampling voltage of the first sampling point and the second sampling voltage of the second sampling point, and determine whether the fast charging positive relay sticks according to the first sampling voltage and the second sampling voltage;

[0047] A negative relay sticking detection module is configured to control the first switch of the relay sticking detection circuit to open and the second switch to close, acquire the third sampling voltage of the third sampling point, and determine whether the fast charging negative relay sticks according to the third sampling voltage;

[0048] A general risk prompt module is configured to generate a general risk prompt information when the fast charging positive relay or the fast charging negative relay sticks;

[0049] A high-voltage power-off control module is configured to perform high-voltage power-off by the battery management system and generate a serious risk prompt information when the fast charging positive relay and the fast charging negative relay both stick;

[0050] The relay sticking detection circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first switch, a second switch, a first diode, a first voltage source, a first sampling point, a second sampling point and a third sampling point.

[0051] In a third aspect, an electric vehicle fast charging relay sticking detection device is provided, comprising:

[0052] at least one processor;

[0053] at least one memory for storing at least one program;

[0054] When the at least one program is executed by the at least one processor, the at least one processor implements the electric vehicle fast charging relay sticking detection method.

[0055] In a fourth aspect, a computer readable storage medium is provided, wherein the computer readable storage medium stores a program executable by a processor, and the program executable by the processor is used to execute the electric vehicle fast charging relay sticking detection method.

[0056] The advantages and beneficial effects of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood by the practice of the present application:

[0057] The embodiment of the present application can detect the sticking of the positive and negative relays in real time at the end of the charging stage, without waiting for the user to perform the high-voltage power-on operation, and only performs the sticking detection once in one charging cycle, avoids repeated detection and excessive wear on the hardware, performs high-voltage power-off and serious risk prompt when the positive and negative relays are detected to be stuck at the same time, in addition, can eliminate the influence of the residual voltage of the charging pile on the detection accuracy, avoid sticking false positives, and improve the timeliness, comprehensiveness and reliability of the fast-charging relay sticking detection. BRIEF DESCRIPTION OF DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following introduces the drawings needed to be used in the embodiments of the present application, and it should be understood that the drawings in the following introduction are only for facilitating the clear description of some embodiments in the technical solutions of the present application, and other drawings can be obtained by those skilled in the art without any creative labor on the basis of these drawings.

[0059] Figure 1 A step flow chart of a fast-charging relay sticking detection method for an electric vehicle provided by the embodiment of the present application is shown in the figure.

[0060] Figure 2 A circuit principle schematic diagram of a relay sticking detection circuit provided by the embodiment of the present application is shown in the figure.

[0061] Figure 3 An instruction diagram of a fast-charging relay sticking detection method for an electric vehicle provided by the embodiment of the present application is shown in the figure.

[0062] Figure 4 A structure block diagram of a fast-charging relay sticking detection system for an electric vehicle provided by the embodiment of the present application is shown in the figure.

[0063] Figure 5 A structure block diagram of a fast-charging relay sticking detection device for an electric vehicle provided by the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0064] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application. For the step numbers in the following embodiments, they are only set for facilitating the description and explanation, and the order between the steps is not limited in any way, and the execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0065] In the description of the present application, the meaning of plurality is two or more than two, if there is a description to the first, the second is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features. In addition, unless otherwise defined, all technical and scientific terms used herein have the same meaning as understood by those skilled in the art.

[0066] Referring to Figure 1 The embodiment of the present application provides a kind of electric vehicle fast charging relay sticking detection method, specifically includes the following steps:

[0067] S101, in response to fast charging relay disconnecting instruction, by battery management system drive fast charging positive relay and fast charging negative relay disconnecting;

[0068] S102, the first switch of relay sticking detection circuit is closed, the second switch is opened, the first sampling voltage of first sampling point and the second sampling voltage of second sampling point are acquired, and whether fast charging positive relay occurs sticking is judged according to first sampling voltage and second sampling voltage;

[0069] S103, the first switch of relay sticking detection circuit is opened, the second switch is closed, the third sampling voltage of third sampling point is acquired, and whether fast charging negative relay occurs sticking is judged according to third sampling voltage;

[0070] S104, when fast charging positive relay or fast charging negative relay occurs sticking, generate ordinary risk prompt information;

[0071] S105, when fast charging positive relay and fast charging negative relay all occur sticking, execute high voltage power down by battery management system, and generate serious risk prompt information;

[0072] Among them, the relay adhesion detection circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first switch, a second switch, a first diode, a first voltage source, a first sampling point, a second sampling point and a third sampling point, one end of the first resistor is connected between the positive end of the fast charging port and the fast charging positive relay, one end of the third resistor is connected between the positive end of the high-voltage battery and the fast charging positive relay, one end of the second resistor, one end of the fourth resistor and one end of the sixth resistor are all connected between the negative end of the high-voltage battery and the fast charging negative relay, one end of the seventh resistor is connected between the negative end of the fast charging port and the fast charging negative relay, one end of the fifth resistor and the negative electrode of the first diode are both connected to the first voltage source, the other end of the first resistor is connected to the other end of the second resistor through the first switch, the other end of the third resistor is connected to the other end of the fourth resistor, the other end of the fifth resistor, the other end of the sixth resistor and the positive electrode of the first diode are all connected to the other end of the seventh resistor through the second switch, the first sampling point is located between the third resistor and the fourth resistor, the second sampling point is located between the first resistor and the second resistor, and the third sampling point is located between the sixth resistor and the second switch.

[0073] like Figure 2 The figure shows a schematic diagram of the circuit principle of the relay adhesion detection circuit provided by an embodiment of the present invention. In the figure, R1 to R7 represent the first to seventh resistors, S1 and S2 represent the first switch and the second switch respectively, D1 represents the first diode, 1 and 2 represent its positive terminal and negative terminal respectively, U represents the first voltage source, A, C and D represent the first sampling point, the second sampling point and the third sampling point respectively, V + Indicates the positive terminal of the fast charging port, V - Indicates the negative terminal of the fast charging port, DC + Indicates the positive terminal of the high-voltage battery, DC - Indicates the negative terminal of the high-voltage battery, S + Indicates fast charge positive relay, S - Indicates fast charge negative relay.

[0074] It should be noted that the first switch S1 and the second switch S2 are controlled by different relays, and the first switch S1 and the second switch S2 will not be closed at the same time during detection to avoid the fast charging port positive terminal V + and the negative terminal of the fast charging port V - A loop is formed to eliminate the influence of factors such as the residual voltage of the fast charging port; one end of the second resistor R2, one end of the fourth resistor R4 and one end of the sixth resistor R6 are connected through the third switch ( Figure 2 Not shown) connected to the negative terminal DC of the high voltage battery - With fast charge negative relay S - When the adhesion test is in progress, the third switch is always closed. When the adhesion test is not in progress, the third switch is always open to avoid the DC+ With the negative terminal of the high voltage battery DC - A closed loop is formed for continuous discharge.

[0075] In the fast charge positive relay S + When performing adhesion detection, the first switch S1 is closed and the second switch S2 is opened to obtain the first sampling voltage V at the first sampling point A. A And the first sampling voltage Vc of the second sampling point C, through the first sampling voltage V A The resistance of the third resistor R3 and the fourth resistor R4 can be used to calculate the DC voltage at the positive terminal of the high-voltage battery. + The voltage at the positive terminal of the fast charging port V can be calculated by the second sampling voltage Vc and the resistance values ​​of the first resistor R1 and the second resistor R2. + When the two voltages are consistent or the difference is within a certain error range, it means that the fast charge positive relay S + Adhesion occurs. When the difference between the two exceeds a certain error range, it means that the fast charging positive relay S + No adhesion occurred.

[0076] In the fast charge negative relay S - When performing adhesion detection, close the first switch S1 and open the second switch S2. It can be seen that when the fast charge negative relay S - When disconnected, due to the negative terminal V - Ungrounded, high voltage battery negative terminal DC - Grounded, the seventh resistor R7 does not participate in the shunting of the sixth resistor R6, when the fast charging negative relay S - When the 1st resistor R7 is closed, the seventh resistor R7 will participate in the shunting of the sixth resistor R6. At this time, the third sampling voltage V D , according to the third sampling voltage V D The size of the fast charge negative relay S can be used to determine - Check whether adhesion occurs.

[0077] It can be recognized that there is no mandatory requirement for the adhesion detection of the fast charging positive relay and the fast charging negative relay. The positive relay can be fast charged first and then the negative relay, or the positive and negative appliances can be fast charged first and then the positive relay. The embodiment of the present invention does not limit this.

[0078] like Figure 3 The following is an instruction diagram of a method for detecting adhesion of an electric vehicle fast charging relay provided by an embodiment of the present invention. Figure 2 and Figure 3 The electric vehicle fast charging relay adhesion detection method according to an embodiment of the present invention is further described.

[0079] Further as the optional implementation, the resistance ratio of the first resistance and the second resistance is equal to the resistance ratio of the third resistance and the fourth resistance, and the fast charging positive relay whether to be stuck is judged according to the first sampling voltage and the second sampling voltage, and the specific steps include:

[0080] S1021, the voltage difference absolute value of the first sampling voltage and the second sampling voltage is calculated;

[0081] S1022, when the voltage difference absolute value is greater than the preset positive sticking threshold, it is determined that the fast charging positive relay is not stuck;

[0082] S1023, when the voltage difference absolute value is less than or equal to the positive sticking threshold, it is determined that the fast charging positive relay is stuck.

[0083] In the embodiment of the application, the resistance ratio of the first resistance R1 and the second resistance R2 is equal to the resistance ratio of the third resistance R3 and the fourth resistance R4, so that when the fast charging positive relay is stuck, theoretically, the first sampling voltage V A and the second sampling voltage Vc should be equal, but considering the positive and negative limit errors of the voltage sensor, there may be a case that the fast charging positive relay is stuck but the first sampling voltage V A and the second sampling voltage Vc are not equal in the actual detection process.

[0084] Based on this, the embodiment of the application sets a positive sticking threshold according to the positive and negative limit errors of the voltage sensor in advance, when the voltage difference absolute value of the first sampling voltage V A and the second sampling voltage Vc is greater than or equal to the positive sticking threshold, it indicates that the voltage difference between the positive end of the high-voltage battery and the positive end of the fast charging port is large, and the fast charging positive relay is not stuck, when the voltage difference absolute value of the first sampling voltage V A and the second sampling voltage Vc is less than or equal to the positive sticking threshold, it indicates that the voltage difference between the positive end of the high-voltage battery and the positive end of the fast charging port is small, and the fast charging positive relay is stuck.

[0085] Further as the optional implementation, the first sampling voltage is obtained by the first voltage sensor, the second sampling voltage is obtained by the second voltage sensor, and the positive sticking threshold is determined by the following steps:

[0086] S201, the first positive error and the first negative error of the first voltage sensor are determined;

[0087] S202, the second positive error and the second negative error of the second voltage sensor are determined;

[0088] S203, the first error threshold is determined according to the difference value of the first positive error and the second negative error, and the second error threshold is determined according to the difference value of the second positive error and the second negative error;

[0089] S204, select the maximum value between the first error threshold and the second error threshold as the positive sticking threshold.

[0090] Specifically, the value of the positive sticking threshold needs to be determined according to the positive and negative limit errors of the first voltage sensor and the second voltage sensor.

[0091] Suppose the first positive error of the first voltage sensor is The first negative error is The second positive error of the second voltage sensor is The second negative error is When the actual voltage values of the first sampling point and the second sampling point are both U0, the first sampling voltage sampled by the first voltage sensor is The second sampling voltage sampled by the second voltage sensor is Therefore, when the first sampling voltage V A takes the maximum value The second sampling voltage Vc takes the minimum value , the absolute value of the voltage difference between the two is (namely, the first error threshold), when the first sampling voltage V A takes the minimum value The second sampling voltage Vc takes the maximum value , the absolute value of the voltage difference between the two is (namely, the second error threshold).

[0092] From the above analysis, when the actual voltage values of the first sampling point and the second sampling point are both U0, the absolute value of the voltage value of the first sampling voltage and the second sampling voltage will not exceed the larger one of the first error threshold and the second error threshold, that is, the maximum value between the first error threshold and the second error threshold can be selected as the positive sticking threshold, when the absolute value of the voltage difference between the two is greater than the positive sticking threshold, it is determined that the fast charging positive relay does not stick, and when the absolute value of the voltage difference between the two is less than or equal to the positive sticking threshold, it is determined that the fast charging positive relay sticks.

[0093] It should be noted that in the embodiment of the application, the charging pile side does not supply power after the charging is completed, so if the fast charging positive relay is normally disconnected, the voltage at the positive end of the fast charging port will be greatly different from the voltage at the positive end of the high-voltage battery. Therefore, as long as the errors of the first voltage sensor and the second voltage sensor meet the factory standard of normal voltage sensors, even if the limit error occurs during sampling, it will not affect the determination of whether the fast charging positive relay sticks.

[0094] Further as an optional implementation manner, the fast charging negative relay is determined whether to stick according to the third sampling voltage, which specifically includes:

[0095] S1021, when the third sampling voltage is greater than or equal to a preset negative adhesion threshold value, it is determined that the fast charging negative relay does not occur adhesion;

[0096] S1022, when the third sampling voltage is less than the negative adhesion threshold value, it is determined that the fast charging negative relay occurs adhesion.

[0097] Further as an optional implementation, the third sampling voltage is obtained by sampling through a third voltage sensor, and the negative adhesion threshold value is determined by the following formula:

[0098]

[0099] Wherein, V 负 represents the negative adhesion threshold value, R5 represents the resistance value of the fifth resistor, R6 represents the resistance value of the sixth resistor, R7 represents the resistance value of the seventh resistor, U represents the voltage value of the first voltage source (5-12V can be taken), represents the third positive error of the third voltage sensor, represents the third negative error of the third voltage sensor.

[0100] In the embodiment of the application, when the fast charging negative relay occurs adhesion, the seventh resistor R7 will participate in the shunt of the sixth resistor R6, and theoretically the actual voltage value of the third sampling point D should be When the fast charging negative relay does not occur adhesion, the seventh resistor R7 does not participate in the shunt of the sixth resistor R6, and theoretically the actual voltage value of the third sampling point D should be Therefore, in theory, as long as the selected negative adhesion threshold value satisfies When the third sampling voltage is greater than or equal to the negative adhesion threshold value, it is determined that the fast charging negative relay does not occur adhesion, and when the third sampling voltage is less than the negative adhesion threshold value, it is determined that the fast charging negative relay occurs adhesion.

[0101] But in the actual detection process, considering the positive and negative limit errors of the voltage sensor, the third sampling voltage obtained by sampling when the fast charging negative relay occurs adhesion may be less than The third sampling voltage obtained by sampling when the fast charging negative relay does not occur adhesion may also be greater than Therefore, if the negative adhesion threshold value is limited only in the range of U, it is likely to produce false judgment.

[0102] Based on this, the embodiment of the application limits the selection of the negative adhesion threshold value in combination with the positive and negative limit errors of the third voltage sensor, specifically, assuming that the third positive error of the third voltage sensor is The third negative error of the third voltage sensor is The third sampling voltage obtained by sampling when the fast charging negative relay occurs adhesion is The third sampling voltage obtained by sampling when the fast charging negative relay does not occur adhesion Therefore, the negative adhesion threshold value can be defined as That is, it can be ensured that when the third sampling voltage is greater than or equal to the negative adhesion threshold value, the fast-charging negative relay does not occur adhesion, and when the third sampling voltage is less than the negative adhesion threshold value, the fast-charging negative relay occurs adhesion.

[0103] It should be noted that when selecting the fifth resistor, the sixth resistor, the seventh resistor, the first voltage source, and the third voltage sensor, it needs to meet Avoid the actual interval of the third sampling voltage under different situations from crossing to cause misjudgment.

[0104] Further, as an optional implementation, the battery management system performs high-voltage power down, and generates a serious risk prompt information, which specifically includes:

[0105] S1051, judge whether the vehicle speed is 0, and judge whether the vehicle is in P gear;

[0106] S1052, when the vehicle speed is 0 and the vehicle is in P gear, the battery management system performs high-voltage power down, generates a serious risk prompt information and pushes it to the user;

[0107] S1053, when the vehicle speed is not 0 and / or the vehicle is not in P gear, a serious risk prompt information is generated and broadcasted in the vehicle, and then the battery management system performs high-voltage power down when the vehicle speed drops to 0 and / or the vehicle gear is shifted to P gear.

[0108] Specifically, when only one of the fast-charging positive relay and the fast-charging negative relay occurs adhesion, a general risk prompt information (such as MID text prompt) is generated and pushed to the user; when both the fast-charging positive relay and the fast-charging negative relay occur adhesion, there is a high risk of the charging port at this time, and the vehicle needs to be in a power down state while sending a serious risk prompt information.

[0109] Specifically, when both the fast-charging positive relay and the fast-charging negative relay occur adhesion, it is judged whether the vehicle speed is 0 and whether the vehicle is in P gear, when the vehicle speed is 0 and the vehicle is in P gear, the battery management system performs high-voltage power down, and generates a serious risk prompt information and pushes it to the user; when the vehicle speed is not 0 and / or the vehicle is not in P gear, it means that the vehicle is running at this time, and a serious risk prompt information needs to be generated and broadcasted in the vehicle, reminding the user to park, and then the battery management system performs high-voltage power down when the vehicle speed drops to 0 and / or the vehicle gear is shifted to P gear.

[0110] Further, as an optional implementation, the electric vehicle fast-charging relay adhesion detection method further includes the following steps:

[0111] S106, after judging whether the fast charging positive relay and the fast charging negative relay are stuck, setting the relay sticking detection implementation history of the vehicle to a detected state;

[0112] S107, when the vehicle enters the next charging cycle and the battery management system drives the fast charging positive relay and the fast charging negative relay to close, setting the relay sticking detection implementation history to an undetected state;

[0113] The relay sticking detection implementation history is used to judge whether to perform the sticking detection of the fast charging positive relay and the fast charging negative relay. When the relay sticking detection implementation history is in the detected state, the sticking detection of the fast charging positive relay and the fast charging negative relay is no longer repeatedly performed. When the relay sticking detection implementation history is in the undetected state, the sticking detection of the fast charging positive relay and the fast charging negative relay is performed after the fast charging positive relay and the fast charging negative relay are driven to open by the battery management system.

[0114] Specifically, the embodiment of the present application sets the relay sticking detection implementation history in the battery management system. Before the sticking detection of the fast charging positive relay and the fast charging negative relay is performed, it is judged whether the relay sticking detection implementation history is in the undetected state (0). If yes, the subsequent detection is performed. After judging whether the fast charging positive relay and the fast charging negative relay are stuck, the relay sticking detection implementation history is set to the detected state (1). Thus, the sticking detection of the fast charging positive relay and the fast charging negative relay is no longer repeatedly performed before the next charging cycle. After the vehicle enters the next charging cycle and the battery management system drives the fast charging positive relay and the fast charging negative relay to close, the relay sticking detection implementation history is reset to the undetected state (0).

[0115] The method steps of the embodiment of the present application are described above. The embodiment of the present application realizes the sticking detection of the fast charging positive relay and the fast charging negative relay through circuit design and software strategy. After the relay opening instruction is issued at the end of charging, the sticking detection of the fast charging positive / negative relay is started. After the sticking of the positive / negative relay is detected, the high-voltage power-off safety protection is performed while the major safety risk is prompted. After the sticking detection is performed once, the implementation history is stored in the battery management system until the implementation history is reset in the next charging cycle, so as to avoid repeated excessive detection. Through the independent control mode of the circuit switch, the influence of the charging pile side is eliminated, and the sticking false alarm is avoided.

[0116] It can be recognized that the embodiment of the application can complete the adhesion detection of the fast charging positive and negative relays in real time at the end of the charging stage, without waiting for the user to perform the high-voltage power-on operation, and the adhesion detection is performed only once in one charging cycle, avoiding excessive wear on the hardware caused by repeated detection, and when the positive and negative relays are detected to be adhered at the same time, the high-voltage power-off and serious risk prompt are performed, in addition, the influence of the residual voltage of the charging pile on the detection accuracy can be eliminated, the adhesion false alarm is avoided, and the timeliness, comprehensiveness and reliability of the fast charging relay adhesion detection are improved.

[0117] With reference to Figure 4 The embodiment of the application provides a fast charging relay adhesion detection system for an electric vehicle, which comprises:

[0118] A relay driving module is configured to drive the fast charging positive relay and the fast charging negative relay to be disconnected through the battery management system in response to a fast charging relay disconnection instruction.

[0119] A positive relay adhesion detection module is configured to control the first switch of the relay adhesion detection circuit to be closed and the second switch to be opened, acquire a first sampling voltage at a first sampling point and a second sampling voltage at a second sampling point, and determine whether the fast charging positive relay is adhered according to the first sampling voltage and the second sampling voltage.

[0120] A negative relay adhesion detection module is configured to control the first switch of the relay adhesion detection circuit to be opened and the second switch to be closed, acquire a third sampling voltage at a third sampling point, and determine whether the fast charging negative relay is adhered according to the third sampling voltage.

[0121] A common risk prompt module is configured to generate a common risk prompt information when the fast charging positive relay or the fast charging negative relay is adhered.

[0122] A high-voltage power-off control module is configured to perform the high-voltage power-off through the battery management system and generate a serious risk prompt information when the fast charging positive relay and the fast charging negative relay are adhered.

[0123] The relay sticking detection circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first switch, a second switch, a first diode, a first voltage source, a first sampling point, a second sampling point and a third sampling point.

[0124] The content in the method embodiments is applicable to the system embodiments, the system embodiments specifically implement the functions of the method embodiments, and achieve the same beneficial effects as the method embodiments.

[0125] Referring to Figure 5 The system embodiment of the application provides an electric vehicle fast-charging relay sticking detection device, which comprises:

[0126] at least one processor;

[0127] at least one memory for storing at least one program;

[0128] When the at least one program is executed by the at least one processor, the at least one processor implements the electric vehicle fast-charging relay sticking detection method.

[0129] The content in the method embodiments is applicable to the device embodiments, the device embodiments specifically implement the functions of the method embodiments, and achieve the same beneficial effects as the method embodiments.

[0130] The embodiment of the application further provides a computer readable storage medium, wherein the computer readable storage medium stores a program executable by a processor, and the program executable by the processor is used for executing the electric vehicle fast-charging relay sticking detection method when the program executable by the processor is executed by the processor.

[0131] The computer readable storage medium of the embodiment of the present application can execute the electric vehicle fast charging relay sticking detection method provided by the method embodiment of the present application, and can execute the step of any combination of the method embodiment, has the corresponding function and beneficial effect of the method.

[0132] The embodiment of the present application also discloses a computer program product or computer program, the computer program product or computer program comprises computer instructions, the computer instructions are stored in the computer readable storage medium. The processor of the computer equipment can read the computer instructions from the computer readable storage medium, and the processor executes the computer instructions, so that the computer equipment executes the method shown in the figure. Figure 1 The method shown in the figure.

[0133] In some alternative embodiments, the functions / operations mentioned in the block diagram can not occur in the order mentioned in the operation diagram. For example, depending on the functions / operations involved, two blocks shown in succession can actually be executed substantially simultaneously or the above blocks can be executed in reverse order at times. In addition, the embodiments presented and described in the flowcharts of the present application are provided by way of example, with the purpose of providing a more comprehensive understanding of the technology. The disclosed method is not limited to the operations and logical flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and in which sub-operations described as part of larger operations are independently executed.

[0134] In addition, although the present application is described in the context of functional modules, it should be understood that, unless otherwise stated to the contrary, one or more of the above-mentioned functions and / or features can be integrated in a single physical device and / or software module, or one or more functions and / or features can be implemented in separate physical devices or software modules. It can also be understood that detailed discussion of the actual implementation of each module is unnecessary for understanding the present application. Rather, given the properties, functions and internal relationships of the various functional modules in the devices disclosed herein, the actual implementation of the module will be understood within the routine skill of an engineer. Therefore, those skilled in the art can implement the present application as set forth in the claims without undue experimentation using ordinary skill. It can also be understood that the disclosed specific concepts are merely illustrative and are not intended to limit the scope of the present application, the scope of the present application being determined by the full scope of the appended claims and their equivalents.

[0135] If the above functions are realized in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application or parts of the technical solutions that essentially contribute to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described above in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0136] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a list of executable instructions for implementing logic functions, which can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus or device, such as a computer-based system, a system including a processor or other system that can fetch the instructions from the instruction execution system, apparatus or device and execute the instructions, or in conjunction with these instructions execution systems, apparatus or devices. For the purpose of this specification, the "computer-readable medium" can be any device that can contain, store, communicate, propagate or transport programs for use by or in connection with an instruction execution system, apparatus or device, or in conjunction with these instruction execution systems, apparatus or devices.

[0137] More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection having one or more wires (electrical devices), a portable computer diskette (magnetic devices), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium can even be paper or other suitable medium on which the aforementioned programs can be printed, because the aforementioned programs can be obtained electronically, for example, by optical scanning of the paper or other medium, followed by editing, interpreting or otherwise processing, if necessary, in other suitable ways, to be stored in the computer memory.

[0138] It should be understood that various parts of the present application can be implemented in hardware, software, firmware or a combination thereof. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following technologies, known in the art, or their equivalents, can be employed for implementation: discrete logic circuitry having logic gates for implementing logic functions upon data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and the like.

[0139] In the above description of the present specification, the description of the terms "one embodiment / one example", "another embodiment / another example", or "certain embodiments / certain examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0140] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made thereto without departing from the principles and spirit of the present application, the scope of which is defined by the claims and their equivalents.

[0141] The above is a specific description of the preferred embodiments of the present application, but the present application is not limited to the above-described embodiments, and those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present application, and these equivalent modifications or substitutions are included in the scope defined by the claims of the present application.

Claims

1. A method for detecting adhesion of an electric vehicle fast charging relay, characterized in that: The following steps are involved: In response to the fast charge relay disconnection instruction, the battery management system drives the fast charge positive relay and the fast charge negative relay to disconnect; Control the first switch of the relay adhesion detection circuit to be closed and the second switch to be open, obtain a first sampling voltage at a first sampling point and a second sampling voltage at a second sampling point, and determine whether the fast charging positive relay is adhered based on the first sampling voltage and the second sampling voltage; Controlling the first switch of the relay adhesion detection circuit to be open and the second switch to be closed, obtaining a third sampling voltage at a third sampling point, and determining whether the fast charging negative relay is adhered according to the third sampling voltage; When the fast charging positive relay or the fast charging negative relay is stuck, a general risk warning message is generated; When both the fast charge positive relay and the fast charge negative relay are stuck, the battery management system executes high voltage power-off and generates a serious risk warning message; Wherein, the relay adhesion detection circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first switch, a second switch, a first diode, a first voltage source, a first sampling point, a second sampling point and a third sampling point, one end of the first resistor is connected between the positive end of the fast charging port and the fast charging positive relay, one end of the third resistor is connected between the positive end of the high-voltage battery and the fast charging positive relay, one end of the second resistor, one end of the fourth resistor and one end of the sixth resistor are all connected between the negative end of the high-voltage battery and the fast charging negative relay, one end of the seventh resistor is connected between the negative end of the fast charging port and the fast charging positive relay. a first terminal of the first resistor and a second terminal of the first diode are connected to each other via the second switch; a first terminal of the first resistor and a second terminal of the sixth resistor are connected to each other via the second switch; a first sampling point is located between the third resistor and the fourth resistor; a second sampling point is located between the first resistor and the second resistor; and a third sampling point is located between the sixth resistor and the second switch.

2. The method for detecting adhesion of an electric vehicle fast charging relay according to claim 1, wherein: The resistance ratio of the first resistor to the second resistor is equal to the resistance ratio of the third resistor to the fourth resistor, and the determining whether the fast charging positive relay is stuck according to the first sampling voltage and the second sampling voltage specifically includes: calculating an absolute value of a voltage difference between the first sampling voltage and the second sampling voltage; When the absolute value of the voltage difference is greater than a preset positive sticking threshold, it is determined that the fast charge positive relay is not stuck; When the absolute value of the voltage difference is less than or equal to the positive sticking threshold, it is determined that the fast charging positive relay is stuck.

3. The method for detecting adhesion of an electric vehicle fast charging relay according to claim 2, wherein: The first sampling voltage is obtained by sampling a first voltage sensor, the second sampling voltage is obtained by sampling a second voltage sensor, and the positive adhesion threshold is determined by the following steps: determining a first positive error and a first negative error of the first voltage sensor; determining a second positive error and a second negative error of the second voltage sensor; determining a first error threshold according to a difference between the first positive error and the second negative error, and determining a second error threshold according to a difference between the second positive error and the second negative error; The maximum value between the first error threshold and the second error threshold is selected as the positive adhesion threshold.

4. The method for detecting adhesion of an electric vehicle fast charging relay according to claim 1, wherein: The determining whether the fast charging negative relay is stuck according to the third sampling voltage specifically includes: When the third sampling voltage is greater than or equal to a preset negative adhesion threshold, it is determined that the fast charging negative relay is not stuck; When the third sampling voltage is less than the negative sticking threshold, it is determined that the fast charging negative device is stuck.

5. The method for detecting adhesion of an electric vehicle fast charging relay according to claim 4, wherein: The third sampling voltage is obtained by sampling the third voltage sensor, and the negative adhesion threshold is determined by the following formula: Among them, V 负 represents the negative sticking threshold, R5 represents the resistance value of the fifth resistor, R6 represents the resistance value of the sixth resistor, R7 represents the resistance value of the seventh resistor, U represents the voltage value of the first voltage source, represents a third positive error of the third voltage sensor, represents a third negative error of the third voltage sensor.

6. The method for detecting adhesion of an electric vehicle fast charging relay according to claim 1, wherein: The battery management system is used to execute high voltage power-off and generate serious risk warning information, which specifically includes: Determine whether the vehicle speed is 0 and whether the vehicle is in P gear; When the vehicle speed is 0 and the vehicle is in P gear, the battery management system executes high-voltage power-down, generates a serious risk warning message and pushes it to the user; When the vehicle speed is not 0 and / or the vehicle is not in P gear, a serious risk warning message is generated and broadcast in the vehicle, and then after the vehicle speed drops to 0 and / or the vehicle is shifted to P gear, the battery management system executes high-voltage power-down.

7. A method for detecting adhesion of an electric vehicle fast charging relay according to any one of claims 1 to 6, characterized in that: The electric vehicle fast charging relay adhesion detection method further includes the following steps: After determining whether the fast charge positive relay and the fast charge negative relay are stuck, setting the relay sticking detection implementation history of the vehicle to a detected state; When the vehicle enters the next charging cycle and the battery management system drives the fast charging positive relay and the fast charging negative relay to close, the relay adhesion detection implementation history is set to an undetected state; Among them, the relay adhesion detection implementation history is used to determine whether to perform the adhesion detection of the fast charging positive relay and the fast charging negative relay. When the relay adhesion detection implementation history is in a detected state, the adhesion detection of the fast charging positive relay and the fast charging negative relay will no longer be repeatedly executed. When the relay adhesion detection implementation history is in an undetected state, the adhesion detection of the fast charging positive relay and the fast charging negative relay will be executed after the fast charging positive relay and the fast charging negative relay are driven to disconnect by the battery management system.

8. An electric vehicle fast charging relay adhesion detection system, characterized in that: include: A relay driver module is used to drive the fast charge positive relay and the fast charge negative relay to disconnect via the battery management system in response to a fast charge relay disconnect instruction; A positive relay adhesion detection module is used to control the first switch of the relay adhesion detection circuit to close and the second switch to open, obtain a first sampling voltage at a first sampling point and a second sampling voltage at a second sampling point, and determine whether the fast charging positive relay is adhered based on the first sampling voltage and the second sampling voltage; A negative relay adhesion detection module is used to control the first switch of the relay adhesion detection circuit to be open and the second switch to be closed, obtain a third sampling voltage of a third sampling point, and determine whether the fast charging negative relay is adhered according to the third sampling voltage; A general risk warning module is used to generate general risk warning information when the fast charging positive relay or the fast charging negative relay is stuck; A high-voltage power-off control module, configured to execute high-voltage power-off through the battery management system and generate a serious risk warning message when both the fast-charge positive relay and the fast-charge negative relay are stuck; Wherein, the relay adhesion detection circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first switch, a second switch, a first diode, a first voltage source, a first sampling point, a second sampling point and a third sampling point, one end of the first resistor is connected between the positive end of the fast charging port and the fast charging positive relay, one end of the third resistor is connected between the positive end of the high-voltage battery and the fast charging positive relay, one end of the second resistor, one end of the fourth resistor and one end of the sixth resistor are all connected between the negative end of the high-voltage battery and the fast charging negative relay, one end of the seventh resistor is connected between the negative end of the fast charging port and the fast charging positive relay. a first terminal of the first resistor and a second terminal of the first diode are connected to each other via the second switch; a first terminal of the first resistor and a second terminal of the sixth resistor are connected to each other via the second switch; a first sampling point is located between the third resistor and the fourth resistor; a second sampling point is located between the first resistor and the second resistor; and a third sampling point is located between the sixth resistor and the second switch.

9. An electric vehicle fast charging relay adhesion detection device, characterized in that: include: at least one processor; at least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the electric vehicle fast charging relay adhesion detection method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a program executable by a processor, characterized in that: The program executable by the processor is used to execute the electric vehicle fast charging relay adhesion detection method as described in any one of claims 1 to 7 when executed by the processor.

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