Relay sticking detection method, system, device, and storage medium

Abstract

The application discloses a relay sticking detection method, system, device and storage medium, and the method comprises the steps of determining a target relay according to vehicle state information under a preset working condition; obtaining a front-stage voltage detection value of the target relay and a rear-end voltage detection value of the target relay; and performing sticking detection on the target relay based on a DC-BOX controller according to the front-stage voltage detection value of the target relay, the rear-end voltage detection value of the target relay and a current battery voltage value. Compared with the prior art, plug-in hybrid electric vehicles only have an alternating current slow charging function, but public charging piles are direct current fast charging piles for operation, so that electric vehicles with the alternating current slow charging function are inconvenient to charge outdoors, and the DC-BOX controller is additionally installed to realize the direct current fast charging function, and then the sticking detection is performed on the target relay, so that the relay state is effectively detected, and the protection effect on the high-voltage safety of the whole vehicle and the high-voltage safety of a fast charging port is achieved.

Description

Technical Field

[0001] This invention relates to the field of relay testing technology, and in particular to a method, system, device, and storage medium for detecting relay adhesion. Background Technology

[0002] Currently, most plug-in hybrid electric vehicles only have AC slow charging capability and lack DC fast charging capability, but this charging method is suitable for home charging. Most public charging stations are commercial DC fast charging stations, making it inconvenient for electric vehicles with only AC slow charging capability to charge outdoors. Therefore, how to accurately control the relay status to facilitate charging function control has become an urgent problem to be solved.

[0003] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The main objective of this invention is to provide a method, system, device, and storage medium for detecting relay adhesion, aiming to solve the technical problem of how to accurately grasp the state of a relay for easy control of the charging function.

[0005] To achieve the above objectives, the present invention provides a method for detecting relay adhesion, the method comprising:

[0006] Under preset operating conditions, the target relay is determined based on the vehicle status information;

[0007] Obtain the front-end voltage detection value and the rear-end voltage detection value of the target relay;

[0008] The DC-BOX controller performs adhesion detection on the target relay based on the front voltage detection value, the back voltage detection value, and the current battery voltage value.

[0009] Optionally, the step of determining the target relay based on vehicle status information under preset operating conditions includes:

[0010] Under preset operating conditions, high-voltage command information sent by the vehicle controller is obtained based on vehicle status information;

[0011] When the high-voltage command information is an up-high-voltage command information, the plug connection status is detected;

[0012] When the insertion gun is in an unconnected state, the target relay is either a main positive relay or a main negative relay.

[0013] Optionally, the step of determining the target relay based on vehicle status information under preset operating conditions further includes:

[0014] Under preset operating conditions, the connector connection information is determined based on the vehicle status information;

[0015] When the plug connection information is in an unconnected state and the battery is under high voltage, or when the plug connection information is in a disconnected state and the battery is not under high voltage, the target relay is a fast charging relay.

[0016] Optionally, the step of detecting adhesion of the target relay based on the DC-BOX controller according to the front-end voltage detection value of the target relay, the rear-end voltage detection value of the target relay, and the current battery voltage value further includes:

[0017] The DC-BOX controller determines the voltage difference of the target relay based on the detected voltage values ​​of the front and rear ends of the target relay.

[0018] Determine the preset voltage threshold based on the current battery voltage value and percentage threshold;

[0019] Determine whether the voltage difference of the target relay is less than or equal to the preset voltage threshold;

[0020] When the voltage difference of the target relay is less than or equal to the preset voltage threshold, the target relay is determined to be in a stuck state, and a stuck fault is reported for the target relay.

[0021] When the voltage difference of the target relay is greater than the preset voltage threshold, the target relay is determined to be in a normal state.

[0022] Optionally, after the step of detecting adhesion of the target relay based on the DC-BOX controller using the front-end voltage detection value of the target relay, the rear-end voltage detection value of the target relay, and the current battery voltage value, the method further includes:

[0023] Determine if the current vehicle speed is less than the preset speed;

[0024] When the current vehicle speed is less than the preset vehicle speed, determine whether the target relay is stuck.

[0025] If so, high voltage should be prevented from being applied to the battery, and a high voltage system fault should be indicated on the instrument panel.

[0026] Optionally, the step of determining the target relay based on vehicle status information under preset operating conditions further includes:

[0027] Under preset operating conditions, high-voltage command information sent by the vehicle controller is obtained based on vehicle status information;

[0028] When the high-voltage command information is a lower high-voltage command information, the relay operation is disconnected, and the target relay is either a main positive relay or a main negative relay.

[0029] Optionally, the step of detecting adhesion of the target relay based on the DC-BOX controller according to the front-end voltage detection value of the target relay, the rear-end voltage detection value of the target relay, and the current battery voltage value further includes:

[0030] The DC-BOX controller determines the voltage difference of the target relay based on the detected voltage values ​​of the front and rear ends of the target relay.

[0031] Determine the preset voltage threshold based on the current battery voltage value and percentage threshold;

[0032] When the bus current is less than the preset current and the voltage difference of the target relay is less than or equal to the preset voltage threshold, the target relay is determined to be in a stuck state, and a stuck fault is reported for the target relay.

[0033] When the voltage difference of the target relay is greater than the preset voltage threshold, the target relay is determined to be in a normal state.

[0034] Furthermore, to achieve the above objectives, the present invention also proposes a relay adhesion detection system, the relay adhesion detection system comprising:

[0035] The determination module is used to determine the target relay based on vehicle status information under preset operating conditions;

[0036] The acquisition module is used to acquire the front-end voltage detection value of the target relay and the rear-end voltage detection value of the target relay;

[0037] The detection module is used to perform adhesion detection on the target relay based on the front voltage detection value of the target relay, the rear voltage detection value of the target relay, and the current battery voltage value by the DC-BOX controller.

[0038] Furthermore, to achieve the above objectives, the present invention also proposes a relay adhesion detection device, the device comprising: a memory, a processor, and a relay adhesion detection program stored in the memory and executable on the processor, the relay adhesion detection program being configured to implement the steps of the relay adhesion detection method described above.

[0039] Furthermore, to achieve the above objectives, the present invention also proposes a storage medium storing a relay adhesion detection program, wherein when the relay adhesion detection program is executed by a processor, it implements the steps of the relay adhesion detection method described above.

[0040] This invention, under preset operating conditions, first determines the target relay based on vehicle status information, then acquires the front-end voltage detection value and the rear-end voltage detection value of the target relay. Subsequently, based on the DC-BOX controller, it performs adhesion detection on the target relay according to the front-end voltage detection value, the rear-end voltage detection value, and the current battery voltage. Compared to existing technologies where plug-in hybrid electric vehicles only have AC slow charging capabilities and lack DC fast charging, this charging method is suitable for home charging. Public charging stations are operational DC fast charging stations, making it inconvenient for electric vehicles with AC slow charging capabilities to charge outdoors. This invention achieves DC fast charging by adding a DC-BOX controller, and then performs adhesion detection on the target relay based on the front-end voltage detection value, the rear-end voltage detection value, and the current battery voltage, thereby effectively detecting the relay status and protecting the high-voltage safety of the entire vehicle and the high-voltage safety of the fast charging port. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the structure of a relay adhesion detection device in the hardware operating environment involved in the embodiments of the present invention;

[0042] Figure 2 This is a flowchart illustrating the first embodiment of the relay adhesion detection method of the present invention;

[0043] Figure 3 This is a schematic diagram of the relay adhesion detection system according to the first embodiment of the relay adhesion detection method of the present invention;

[0044] Figure 4 This is a schematic diagram of the DC-BOX controller in the first embodiment of the relay adhesion detection method of the present invention;

[0045] Figure 5 This is a flowchart illustrating the second embodiment of the relay adhesion detection method of the present invention;

[0046] Figure 6 This is a flowchart illustrating the third embodiment of the relay adhesion detection method of the present invention;

[0047] Figure 7 This is a structural block diagram of the first embodiment of the relay adhesion detection system of the present invention.

[0048] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0049] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0050] Reference Figure 1 , Figure 1 This is a schematic diagram of the relay adhesion detection device in the hardware operating environment involved in the embodiments of the present invention.

[0051] like Figure 1 As shown, the relay adhesion detection device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen or an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wireless-Fidelity (Wi-Fi) interface). The memory 1005 may be high-speed random access memory (RAM) or stable non-volatile memory (NVM), such as a disk storage device. Optionally, the memory 1005 may also be a storage system independent of the aforementioned processor 1001.

[0052] Those skilled in the art will understand that Figure 1 The structure shown does not constitute a limitation on the relay adhesion detection device and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0053] like Figure 1 As shown, the memory 1005, which serves as a storage medium, may include an operating system, a network communication module, a user interface module, and a relay adhesion detection program.

[0054] exist Figure 1 In the relay adhesion detection device shown, the network interface 1004 is mainly used for data communication with the network server; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the relay adhesion detection device of the present invention can be set in the relay adhesion detection device, and the relay adhesion detection device calls the relay adhesion detection program stored in the memory 1005 through the processor 1001 and executes the relay adhesion detection method provided in the embodiment of the present invention.

[0055] This invention provides a method for detecting relay adhesion, referring to... Figure 2 , Figure 2 This is a flowchart illustrating the first embodiment of the relay adhesion detection method of the present invention.

[0056] In this embodiment, the relay adhesion detection method includes the following steps:

[0057] Step S10: Under preset operating conditions, determine the target relay based on the vehicle status information.

[0058] It is easy to understand that the execution subject of this embodiment can be a relay adhesion detection device with functions such as data processing, network communication and program operation, or other computer devices with similar functions. This embodiment does not limit it.

[0059] The preset operating conditions include driving conditions and charging conditions, and the target relays include the main positive relay, the main negative relay, and the fast charging relay.

[0060] In this embodiment, under preset operating conditions, the process of determining the target relay based on vehicle status information involves obtaining high-voltage command information sent by the vehicle controller based on the vehicle status information. When the high-voltage command information is an "on high voltage" command, the connection status of the connector is detected. When the connector connection status is "not connected," the target relay is either a main positive relay or a main negative relay. The preset operating conditions refer to driving conditions, and the vehicle status information includes vehicle power-on, etc.

[0061] refer to Figure 3 and Figure 4 , Figure 3 This is a schematic diagram of the relay adhesion detection system according to the first embodiment of the relay adhesion detection method of the present invention. Figure 4 This is a schematic diagram of the DC-BOX controller in the first embodiment of the relay adhesion detection method of the present invention. Figure 3 The relay adhesion detection system includes AC / DC charging sockets, on-board charger (OBC), motor controller (MCU), vehicle controller (VCU), DC-BOX, battery pack, and battery management system (BMS). Figure 4 The DC-BOX controller schematic includes a fast-charging relay, ECU controller, high-voltage connector, and low-voltage connector. The ECU controller has a fast-charging interface circuit, which collects fast-charging port temperature, CC2 connection status, and A+ status, and connects to the fast-charging CAN line and transfers the fast-charging CAN line to the VCU controller. The ECU has voltage detection and fast-charging relay drive functions. The DC-BOX communicates with the BMS via the vehicle's CAN bus.

[0062] In the specific implementation, when the vehicle is powered on, the relay status is checked for adhesion. When the vehicle is in a wake-up state, when the BMS receives the high voltage command sent by the VCU and no plug connection status is detected from the DC-BOX, the BMS checks the main positive relay or the main negative relay for adhesion. The plug status can be detected and reported through the DC-BOX.

[0063] In this embodiment, under preset operating conditions, the method for determining the target relay based on vehicle status information can be as follows: Under preset operating conditions, determine the plug connection information based on the vehicle status information. If the plug connection information is in an unconnected state and the battery is under high voltage, or if the plug connection information is in a disconnected state and the battery is not under high voltage, the target relay is a fast charging relay. The vehicle status information includes whether the vehicle is powered on or fast charging has ended.

[0064] In practical implementation, when the vehicle is powered on, if the DC-BOX detects that the charging gun is not plugged in and the battery is already under high voltage, the DC-BOX performs a fast charging relay sticking detection. Specifically, if the DC-BOX detects that the relay's internal voltage V6 > 200V, it determines that the battery is under high voltage. During charging, at the end of fast charging, if the charging gun is unplugged and there is no CC2 connection or A+ connection, and the battery has not de-energized (the DC-BOX detects that the relay's internal voltage V6 > 200V), the DC-BOX performs a fast charging relay sticking detection.

[0065] In this embodiment, under preset operating conditions, the processing method for determining the target relay based on vehicle status information can also be as follows: under preset operating conditions, obtain the high-voltage command information sent by the vehicle controller based on the vehicle status information; when the high-voltage command information is a de-energizing command, disconnect the relay operation; the target relay is either a main positive relay or a main negative relay. The vehicle status information indicates that the vehicle has de-energized or fast charging has ended.

[0066] In practice, when the vehicle is powered off (driving condition) or fast charging ends (charging condition), after the BMS receives the high voltage command from the VCU, the BMS performs a relay disconnection action to detect adhesion of the main positive relay or the main negative relay.

[0067] Step S20: Obtain the front voltage detection value and the rear voltage detection value of the target relay.

[0068] In the specific implementation, the target relay includes a main positive relay, a main negative relay, and a fast charging relay. The main positive relay has a front voltage detection value V1 and a rear voltage detection value V2. The main negative relay has a front voltage detection value V3 and a rear voltage detection value V4. The fast charging relay has a front voltage detection value V5 and a rear voltage detection value V6.

[0069] Step S30: Based on the DC-BOX controller, the target relay is subjected to adhesion detection according to the front voltage detection value of the target relay, the back voltage detection value of the target relay, and the current battery voltage value.

[0070] Furthermore, the processing method for detecting sticking of the target relay based on the front-end voltage detection value, the back-end voltage detection value, and the current battery voltage value of the target relay by the DC-BOX controller is as follows: The DC-BOX controller determines the voltage difference of the target relay based on the front-end voltage detection value and the back-end voltage detection value of the target relay; it determines a preset voltage threshold based on the current battery voltage value and a percentage threshold; it then determines whether the voltage difference of the target relay is less than or equal to the preset voltage threshold. If the voltage difference of the target relay is less than or equal to the preset voltage threshold, the target relay is determined to be in a sticking state, and a sticking fault is reported for the target relay; if the voltage difference of the target relay is greater than the preset voltage threshold, the target relay is determined to be in a normal state.

[0071] It should be noted that the percentage threshold is a user-defined setting, which can be 3%, 5%, etc.

[0072] Furthermore, based on the DC-BOX controller's operation of detecting adhesion of the target relay according to the front voltage detection value of the target relay, the back voltage detection value of the target relay, and the current battery voltage value, it determines whether the current vehicle speed is less than the preset vehicle speed. If the current vehicle speed is less than the preset vehicle speed, it determines whether the main positive relay and / or the main negative relay and / or the fast charging positive relay are in a state of adhesion. If so, it prohibits the battery from receiving high voltage and prompts a high voltage system fault through the instrument.

[0073] In practical implementation, when the vehicle is powered on and in a wake-up state, after the BMS receives the high-voltage command from the VCU and does not detect any connection status from the DC-BOX, the BMS performs a sticking detection on the main positive relay. If |the front voltage detection value V1 of the main positive relay - the rear voltage detection value V2 of the main positive relay| <= 5% * the current battery voltage value and lasts for a preset duration of 100ms, the main positive relay is considered to be sticking, the BMS reports a main positive relay sticking fault, and prohibits the main positive relay from closing. If |the front voltage detection value V1 of the main positive relay - the rear voltage detection value V2 of the main positive relay| > 5% * the current battery voltage value and lasts for a preset duration of 100ms, the main positive relay is considered to be in normal condition.

[0074] When the vehicle is powered on, and the vehicle is in a wake-up state, after the BMS receives the high-voltage command from the VCU and does not detect any connection status from the DC-BOX, the BMS performs a sticking detection on the main negative relay. If |the front voltage detection value V3 of the main negative relay - the rear voltage detection value V4 of the main negative relay| <= 3% * current battery voltage value and lasts for a preset duration of 100ms, then the main negative relay is considered to be sticking, the BMS reports a main negative relay sticking fault, and prohibits the main negative relay from closing. If |V3 - V4| > 3% * current battery voltage value and lasts for a preset duration of 100ms, then the main negative relay is considered to be in normal condition.

[0075] When the vehicle is powered on, if the DC-BOX detects that the charging gun is not plugged in and the battery is already under high voltage (the DC-BOX detects that the voltage inside the relay, V6 > 200V), the DC-BOX will perform a fast-charging relay sticking detection. If |the front voltage detection value of the fast-charging relay V5 - the rear voltage detection value of the fast-charging relay V6| <= 5% * the current battery voltage value and lasts for a preset duration of 100ms, then the fast-charging positive relay is considered to be sticking, and the DC-BOX will report a fast-charging positive relay sticking fault to the BMS. If |V5 - V6| > 5% * the current battery voltage value and lasts for a preset duration of 100ms, then the fast-charging positive relay is considered to be in normal condition.

[0076] When the BMS detects no sticking faults in the main positive relay, main negative relay, and fast-charging positive relay, and the VCU sends a high-voltage request command, the BMS first closes the main negative relay, then closes the main positive relay to establish high voltage. If a sticking fault occurs in any of the main positive relay, main negative relay, or fast-charging positive relay at a vehicle speed <3km / h, the BMS will not allow high voltage to be applied and will display a high-voltage system fault warning on the instrument panel. This is because attempting to close the main positive and main negative relays when the fast-charging relay is stuck would result in high voltage at the fast-charging port, posing a safety hazard.

[0077] When the vehicle is in motion and the speed is greater than 5 km / h, the BMS and DC-BOX will not perform relay sticking detection. If the BMS or DC-BOX falsely reports a relay sticking fault, the VCU will not request a high-voltage shutdown and will maintain the current driving state. When the vehicle speed drops below 3 km / h, the VCU will handle the relay sticking fault and request the vehicle to be shut down with high voltage.

[0078] It should also be noted that when fast charging ends, if the DC-BOX detects that the charging gun has been unplugged (no CC2 connection and no A+ connection) and the battery voltage has not been reduced (the DC-BOX detects that the relay internal voltage V6 > 200V), the DC-BOX will perform a fast charging relay sticking detection. If |V5-V6| <= 5% * current battery voltage value for a preset duration of 100ms, the fast charging positive relay is considered sticking, and the DC-BOX reports a fast charging positive relay sticking fault to the BMS. If |V5-V6| > 5% * current battery voltage value for a preset duration of 100ms, the fast charging positive relay is considered to be in normal condition. When the DC-BOX reports a fast charging positive relay sticking fault, the VCU needs to request the BMS to reduce the high voltage and disconnect the main positive and main negative relays to prevent the fast charging port from carrying high voltage.

[0079] Furthermore, the processing method of detecting adhesion of the target relay based on the front-end voltage detection value, the back-end voltage detection value, and the current battery voltage value of the target relay by the DC-BOX controller can also be as follows: the DC-BOX controller determines the voltage difference of the target relay based on the front-end voltage detection value and the back-end voltage detection value of the target relay; a preset voltage threshold is determined based on the current battery voltage value and a percentage threshold; when the bus current is less than the preset current and the voltage difference of the target relay is less than or equal to the preset voltage threshold, the target relay is determined to be in an adhesion state, and an adhesion fault is reported for the target relay; when the voltage difference of the target relay is greater than the preset voltage threshold, the target relay is determined to be in a normal state.

[0080] It should be understood that the preset current can be 5A, and this embodiment is not limited to it.

[0081] In practice, when the vehicle is powered off or fast charging ends, after the BMS receives the high-voltage command from the VCU, it disconnects the relay and then checks the main positive relay for sticking. If |bus current| < 5A and |V1-V2| <= 3% * current battery voltage for a preset duration of 100ms, the main positive relay is considered stuck, and the BMS reports a main positive relay sticking fault. If |V1-V2| > 5% * current battery voltage for a preset duration of 100ms, the main positive relay is considered to be in normal condition.

[0082] When the vehicle is de-energized or fast charging ends, upon receiving the de-energization command from the VCU, the BMS disconnects the relay and then checks the main and negative relays for adhesion. If |bus current| < 5A and |V3-V4| <= 3% * current battery voltage for 100ms, the main positive relay is considered to be stuck, and the BMS reports a main negative relay adhesion fault. If |V3-V4| > 3% * current battery voltage for 100ms, the main negative relay is considered to be in normal condition.

[0083] In this embodiment, under preset operating conditions, the target relay is first determined based on the vehicle status information. Then, the front-end voltage detection value and the rear-end voltage detection value of the target relay are obtained. Subsequently, the DC-BOX controller performs adhesion detection on the target relay based on the front-end voltage detection value, the rear-end voltage detection value, and the current battery voltage value. Compared to existing technologies where plug-in hybrid electric vehicles only have AC slow charging capabilities and lack DC fast charging capabilities, this charging method is suitable for home charging. Public charging stations are operational DC fast charging stations, making it inconvenient for electric vehicles with AC slow charging capabilities to charge outdoors. In this embodiment, DC fast charging functionality is achieved by adding a DC-BOX controller. Then, adhesion detection is performed on the target relay based on the front-end voltage detection value, the rear-end voltage detection value, and the current battery voltage value, thereby effectively detecting the relay status and protecting the high-voltage safety of the entire vehicle and the high-voltage safety of the fast charging port.

[0084] refer to Figure 5 , Figure 5 This is a flowchart illustrating the second embodiment of the relay adhesion detection method of the present invention.

[0085] Based on the first embodiment described above, in this embodiment, step S10 further includes:

[0086] Step S1001: Under preset operating conditions, obtain the high-voltage command information sent by the vehicle controller based on the vehicle status information.

[0087] It should be noted that the preset operating condition is the driving condition, and the vehicle status information is that the vehicle is powered on.

[0088] In the specific implementation, when the vehicle is powered on, the relay status is checked for sticking. When the vehicle is in a wake-up state, the BMS receives the high-voltage command sent by the VCU.

[0089] Step S1002: When the high voltage command information is the high voltage command information, detect the connection status of the plug gun.

[0090] It should be understood that the DC-BOX can detect and report the gun insertion status.

[0091] Step S1003: When the insertion gun connection state is not connected, the target relay is a main positive relay or a main negative relay.

[0092] When the BMS receives the high-voltage command from the VCU and does not detect the plug-in connection status from the DC-BOX, the BMS performs adhesion detection on the main positive relay or the main negative relay.

[0093] In this embodiment, step S30 further includes:

[0094] Step S3001: Based on the DC-BOX controller, determine the voltage difference of the target relay according to the front voltage detection value and the back voltage detection value of the target relay.

[0095] In a specific implementation, the target relay includes a main positive relay or a main negative relay. The voltage difference of the main positive relay is obtained by subtracting the absolute value of the voltage detection value of the main positive relay from the voltage detection value of the front end of the main positive relay. The voltage difference of the main negative relay is obtained by subtracting the absolute value of the voltage detection value of the main negative relay from the voltage detection value of the front end of the main negative relay.

[0096] Step S3002: Determine the preset voltage threshold based on the current battery voltage value and the percentage threshold.

[0097] It should be noted that the percentage threshold is a user-defined setting, which can be 3%, 5%, etc.

[0098] Step S3003: Determine whether the voltage difference of the target relay is less than or equal to the preset voltage threshold.

[0099] Step S3004: When the voltage difference of the target relay is less than or equal to the preset voltage threshold, the target relay is determined to be in a stuck state, and a stuck fault is reported for the target relay.

[0100] In the specific implementation, if |the front voltage detection value V1 of the main positive relay - the back voltage detection value V2 of the main positive relay| <= 5% * the current battery voltage value and continues for a preset duration of 100ms, then the main positive relay is considered to be stuck, the BMS reports the main positive relay stuck fault, and prohibits the closing of the main positive relay.

[0101] Step S3005: When the voltage difference of the target relay is greater than the preset voltage threshold, the target relay is determined to be in a normal state.

[0102] If |the front voltage detection value V1 of the main positive relay - the back voltage detection value V2 of the main positive relay| > 5% * the current battery voltage value and continues for a preset duration of 100ms, then the main positive relay is considered to be in normal condition.

[0103] In this embodiment, under preset operating conditions, firstly, the high-voltage command information sent by the vehicle controller is obtained based on the vehicle status information. When the high-voltage command information is an up-high-voltage command information, the connection status of the plug is detected. When the plug connection status is not connected, the target relay is either a main positive relay or a main negative relay. Then, based on the DC-BOX controller, the voltage difference of the target relay is determined according to the front-end voltage detection value and the back-end voltage detection value of the target relay. A preset voltage threshold is determined based on the current battery voltage value and the percentage threshold. It is then determined whether the voltage difference of the target relay is less than or equal to the preset voltage threshold. If the voltage difference of the target relay is less than or equal to the preset voltage threshold, the voltage difference is determined. When the voltage difference equals the preset voltage threshold, the target relay is determined to be in a stuck state, and a stuck fault is reported for the target relay; when the voltage difference of the target relay is greater than the preset voltage threshold, the target relay is determined to be in a normal state. Compared with the prior art, plug-in hybrid electric vehicles only have AC slow charging function and do not have DC fast charging function, so they do not detect the relay status. However, in this embodiment, DC fast charging function is realized by adding a DC-BOX controller. The target relay needs to be determined in advance based on the vehicle status information, and then the sticking detection of the target relay is performed according to the detection strategy, thereby ensuring the high voltage safety of the whole vehicle and the high voltage safety of the fast charging port during the charging process.

[0104] refer to Figure 6 , Figure 6 This is a flowchart illustrating the third embodiment of the relay adhesion detection method of the present invention.

[0105] Based on the first embodiment described above, in this embodiment, step S10 further includes:

[0106] Step S1101: Under preset operating conditions, obtain the high-voltage command information sent by the vehicle controller based on the vehicle status information.

[0107] It should be noted that the preset operating condition is the driving condition, and the vehicle status information is the vehicle being disconnected from the high voltage or the fast charging has ended.

[0108] In practice, when the vehicle is powered off the high voltage or fast charging ends, the BMS receives the high voltage command from the VCU.

[0109] Step S1102: When the high voltage command information is a low voltage command information, disconnect the relay operation, and the target relay is a main positive relay or a main negative relay.

[0110] In this embodiment, when the vehicle is de-energized or fast charging ends, after the BMS receives the high-voltage de-energization command from the VCU, the BMS performs a relay disconnection action and then performs adhesion detection on the main positive relay; when the vehicle is de-energized or fast charging ends, after the BMS receives the high-voltage de-energization command from the VCU, the BMS performs a relay disconnection action and then performs adhesion detection on the main negative relay.

[0111] In this embodiment, step S30 further includes:

[0112] Step S3101: Based on the DC-BOX controller, determine the voltage difference of the target relay according to the front voltage detection value and the back voltage detection value of the target relay.

[0113] In a specific implementation, the target relay includes a main positive relay or a main negative relay. The voltage difference of the main positive relay is obtained by subtracting the absolute value of the voltage detection value of the main positive relay from the voltage detection value of the front end of the main positive relay. The voltage difference of the main negative relay is obtained by subtracting the absolute value of the voltage detection value of the main negative relay from the voltage detection value of the front end of the main negative relay.

[0114] Step S3102: Determine the preset voltage threshold based on the current battery voltage value and the percentage threshold.

[0115] It should be noted that the percentage threshold is a user-defined setting, which can be 3%, 5%, etc.

[0116] Step S3103: When the bus current is less than the preset current and the voltage difference of the target relay is less than or equal to the preset voltage threshold, the target relay is determined to be in a stuck state, and a stuck fault is reported for the target relay.

[0117] It should also be noted that if the |bus current| < 5A, |V1-V2| <= 3% * current battery voltage value, and this condition persists for a preset duration of 100ms, the main positive relay is considered to be stuck, and the BMS will report a main positive relay sticking fault. If the |bus current| < 5A, |V3-V4| <= 3% * current battery voltage value, and this condition persists for 100ms, the main positive relay is considered to be stuck, and the BMS will report a main negative relay sticking fault.

[0118] Step S3104: When the voltage difference of the target relay is greater than the preset voltage threshold, the target relay is determined to be in a normal state.

[0119] The main positive relay is considered to be in normal condition if |V1-V2| > 5% * current battery voltage value and remains so for a preset duration of 100ms. The main negative relay is considered to be in normal condition if |V3-V4| > 3% * current battery voltage value and remains so for 100ms.

[0120] In this embodiment, under preset operating conditions, the high-voltage command information sent by the vehicle controller is first obtained based on the vehicle status information. When the high-voltage command information is a down-voltage command information, the relay operation is disconnected, and the target relay is either a main positive relay or a main negative relay. Then, based on the DC-BOX controller, the voltage difference of the target relay is determined according to the front-end voltage detection value and the back-end voltage detection value of the target relay. Afterwards, a preset voltage threshold is determined based on the current battery voltage value and a percentage threshold. When the bus current is less than the preset current and the voltage difference of the target relay is less than or equal to the preset voltage threshold, the target relay is determined to be in a stuck state, and a stuck fault is reported for the target relay. When the voltage difference of the target relay is greater than the preset voltage threshold, the target relay is determined to be in a normal state. Compared with the prior art where plug-in hybrid electric vehicles only have AC slow charging function, which may require manual control to detect the relay status, this embodiment realizes DC fast charging function by adding a DC-BOX controller. The target relay needs to be determined in advance based on the vehicle status information. Then, in order to ensure the high-voltage safety of the whole vehicle and the high-voltage safety of the fast charging port. The target relay needs to be tested for adhesion according to the detection strategy in order to monitor the relay status in real time and then control the charging.

[0121] Reference Figure 7 , Figure 7 This is a structural block diagram of the first embodiment of the relay adhesion detection system of the present invention.

[0122] like Figure 7 As shown, the relay adhesion detection system proposed in this embodiment of the invention includes:

[0123] The determination module 7001 is used to determine the target relay based on the vehicle status information under preset operating conditions.

[0124] The preset operating conditions include driving conditions and charging conditions, and the target relays include the main positive relay, the main negative relay, and the fast charging relay.

[0125] In this embodiment, under preset operating conditions, the process of determining the target relay based on vehicle status information involves obtaining high-voltage command information sent by the vehicle controller based on the vehicle status information. When the high-voltage command information is an "on high voltage" command, the connection status of the connector is detected. When the connector connection status is "not connected," the target relay is either a main positive relay or a main negative relay. The preset operating conditions refer to driving conditions, and the vehicle status information includes vehicle power-on, etc.

[0126] refer to Figure 3 and Figure 4 , Figure 3 This is a schematic diagram of the relay adhesion detection system according to the first embodiment of the relay adhesion detection method of the present invention. Figure 4This is a schematic diagram of the DC-BOX controller in the first embodiment of the relay adhesion detection method of the present invention. Figure 3 The relay adhesion detection system includes AC / DC charging sockets, on-board charger (OBC), motor controller (MCU), vehicle controller (VCU), DC-BOX, battery pack, and battery management system (BMS). Figure 4 The DC-BOX controller schematic includes a fast-charging relay, ECU controller, high-voltage connector, and low-voltage connector. The ECU controller has a fast-charging interface circuit, which collects fast-charging port temperature, CC2 connection status, and A+ status, and connects to the fast-charging CAN line and transfers the fast-charging CAN line to the VCU controller. The ECU has voltage detection and fast-charging relay drive functions. The DC-BOX communicates with the BMS via the vehicle's CAN bus.

[0127] In the specific implementation, when the vehicle is powered on, the relay status is checked for adhesion. When the vehicle is in a wake-up state, when the BMS receives the high voltage command sent by the VCU and no plug connection status is detected from the DC-BOX, the BMS checks the main positive relay or the main negative relay for adhesion. The plug status can be detected and reported through the DC-BOX.

[0128] In this embodiment, under preset operating conditions, the method for determining the target relay based on vehicle status information can be as follows: Under preset operating conditions, determine the plug connection information based on the vehicle status information. If the plug connection information is in an unconnected state and the battery is under high voltage, or if the plug connection information is in a disconnected state and the battery is not under high voltage, the target relay is a fast charging relay. The vehicle status information includes whether the vehicle is powered on or fast charging has ended.

[0129] In practical implementation, when the vehicle is powered on, if the DC-BOX detects that the charging gun is not plugged in and the battery is already under high voltage, the DC-BOX performs a fast charging relay sticking detection. Specifically, if the DC-BOX detects that the relay's internal voltage V6 > 200V, it determines that the battery is under high voltage. During charging, at the end of fast charging, if the charging gun is unplugged and there is no CC2 connection or A+ connection, and the battery has not de-energized (the DC-BOX detects that the relay's internal voltage V6 > 200V), the DC-BOX performs a fast charging relay sticking detection.

[0130] In this embodiment, under preset operating conditions, the processing method for determining the target relay based on vehicle status information can also be as follows: under preset operating conditions, obtain the high-voltage command information sent by the vehicle controller based on the vehicle status information; when the high-voltage command information is a de-energizing command, disconnect the relay operation; the target relay is either a main positive relay or a main negative relay. The vehicle status information indicates that the vehicle has de-energized or fast charging has ended.

[0131] In practice, when the vehicle is powered off (driving condition) or fast charging ends (charging condition), after the BMS receives the high voltage command from the VCU, the BMS performs a relay disconnection action to detect adhesion of the main positive relay or the main negative relay.

[0132] The acquisition module 7002 is used to acquire the front voltage detection value of the target relay and the back voltage detection value of the target relay.

[0133] In the specific implementation, the target relay includes a main positive relay, a main negative relay, and a fast charging relay. The main positive relay has a front voltage detection value V1 and a rear voltage detection value V2. The main negative relay has a front voltage detection value V3 and a rear voltage detection value V4. The fast charging relay has a front voltage detection value V5 and a rear voltage detection value V6.

[0134] The detection module 7003 is used to perform adhesion detection on the target relay based on the front voltage detection value of the target relay, the rear voltage detection value of the target relay, and the current battery voltage value by the DC-BOX controller.

[0135] Furthermore, the processing method for detecting sticking of the target relay based on the front-end voltage detection value, the back-end voltage detection value, and the current battery voltage value of the target relay by the DC-BOX controller is as follows: The DC-BOX controller determines the voltage difference of the target relay based on the front-end voltage detection value and the back-end voltage detection value of the target relay; it determines a preset voltage threshold based on the current battery voltage value and a percentage threshold; it then determines whether the voltage difference of the target relay is less than or equal to the preset voltage threshold. If the voltage difference of the target relay is less than or equal to the preset voltage threshold, the target relay is determined to be in a sticking state, and a sticking fault is reported for the target relay; if the voltage difference of the target relay is greater than the preset voltage threshold, the target relay is determined to be in a normal state.

[0136] It should be noted that the percentage threshold is a user-defined setting, which can be 3%, 5%, etc.

[0137] Furthermore, based on the DC-BOX controller's operation of detecting adhesion of the target relay according to the front voltage detection value of the target relay, the back voltage detection value of the target relay, and the current battery voltage value, it determines whether the current vehicle speed is less than the preset vehicle speed. If the current vehicle speed is less than the preset vehicle speed, it determines whether the main positive relay and / or the main negative relay and / or the fast charging positive relay are in a state of adhesion. If so, it prohibits the battery from receiving high voltage and prompts a high voltage system fault through the instrument.

[0138] In practical implementation, when the vehicle is powered on and in a wake-up state, after the BMS receives the high-voltage command from the VCU and does not detect any connection status from the DC-BOX, the BMS performs a sticking detection on the main positive relay. If |the front voltage detection value V1 of the main positive relay - the rear voltage detection value V2 of the main positive relay| <= 5% * the current battery voltage value and lasts for a preset duration of 100ms, the main positive relay is considered to be sticking, the BMS reports a main positive relay sticking fault, and prohibits the main positive relay from closing. If |the front voltage detection value V1 of the main positive relay - the rear voltage detection value V2 of the main positive relay| > 5% * the current battery voltage value and lasts for a preset duration of 100ms, the main positive relay is considered to be in normal condition.

[0139] When the vehicle is powered on, and the vehicle is in a wake-up state, after the BMS receives the high-voltage command from the VCU and does not detect any connection status from the DC-BOX, the BMS performs a sticking detection on the main negative relay. If |the front voltage detection value V3 of the main negative relay - the rear voltage detection value V4 of the main negative relay| <= 3% * current battery voltage value and lasts for a preset duration of 100ms, then the main negative relay is considered to be sticking, the BMS reports a main negative relay sticking fault, and prohibits the main negative relay from closing. If |V3 - V4| > 3% * current battery voltage value and lasts for a preset duration of 100ms, then the main negative relay is considered to be in normal condition.

[0140] When the vehicle is powered on, if the DC-BOX detects that the charging gun is not plugged in and the battery is already under high voltage (the DC-BOX detects that the voltage inside the relay, V6 > 200V), the DC-BOX will perform a fast-charging relay sticking detection. If |the front voltage detection value of the fast-charging relay V5 - the rear voltage detection value of the fast-charging relay V6| <= 5% * the current battery voltage value and lasts for a preset duration of 100ms, then the fast-charging positive relay is considered to be sticking, and the DC-BOX will report a fast-charging positive relay sticking fault to the BMS. If |V5 - V6| > 5% * the current battery voltage value and lasts for a preset duration of 100ms, then the fast-charging positive relay is considered to be in normal condition.

[0141] When the BMS detects no sticking faults in the main positive relay, main negative relay, and fast-charging positive relay, and the VCU sends a high-voltage request command, the BMS first closes the main negative relay, then closes the main positive relay to establish high voltage. If a sticking fault occurs in any of the main positive relay, main negative relay, or fast-charging positive relay at a vehicle speed <3km / h, the BMS will not allow high voltage to be applied and will display a high-voltage system fault warning on the instrument panel. This is because attempting to close the main positive and main negative relays when the fast-charging relay is stuck would result in high voltage at the fast-charging port, posing a safety hazard.

[0142] When the vehicle is in motion and the speed is greater than 5 km / h, the BMS and DC-BOX will not perform relay sticking detection. If the BMS or DC-BOX falsely reports a relay sticking fault, the VCU will not request a high-voltage shutdown and will maintain the current driving state. When the vehicle speed drops below 3 km / h, the VCU will handle the relay sticking fault and request the vehicle to be shut down with high voltage.

[0143] It should also be noted that when fast charging ends, if the DC-BOX detects that the charging gun has been unplugged (no CC2 connection and no A+ connection) and the battery voltage has not been reduced (the DC-BOX detects that the relay internal voltage V6 > 200V), the DC-BOX will perform a fast charging relay sticking detection. If |V5-V6| <= 5% * current battery voltage value for a preset duration of 100ms, the fast charging positive relay is considered sticking, and the DC-BOX reports a fast charging positive relay sticking fault to the BMS. If |V5-V6| > 5% * current battery voltage value for a preset duration of 100ms, the fast charging positive relay is considered to be in normal condition. When the DC-BOX reports a fast charging positive relay sticking fault, the VCU needs to request the BMS to reduce the high voltage and disconnect the main positive and main negative relays to prevent the fast charging port from carrying high voltage.

[0144] Furthermore, the processing method of detecting adhesion of the target relay based on the front-end voltage detection value, the back-end voltage detection value, and the current battery voltage value of the target relay by the DC-BOX controller can also be as follows: the DC-BOX controller determines the voltage difference of the target relay based on the front-end voltage detection value and the back-end voltage detection value of the target relay; a preset voltage threshold is determined based on the current battery voltage value and a percentage threshold; when the bus current is less than the preset current and the voltage difference of the target relay is less than or equal to the preset voltage threshold, the target relay is determined to be in an adhesion state, and an adhesion fault is reported for the target relay; when the voltage difference of the target relay is greater than the preset voltage threshold, the target relay is determined to be in a normal state.

[0145] It should be understood that the preset current can be 5A, and this embodiment is not limited to it.

[0146] In practice, when the vehicle is powered off or fast charging ends, after the BMS receives the high-voltage command from the VCU, it disconnects the relay and then checks the main positive relay for sticking. If |bus current| < 5A and |V1-V2| <= 3% * current battery voltage for a preset duration of 100ms, the main positive relay is considered stuck, and the BMS reports a main positive relay sticking fault. If |V1-V2| > 5% * current battery voltage for a preset duration of 100ms, the main positive relay is considered to be in normal condition.

[0147] When the vehicle is de-energized or fast charging ends, upon receiving the de-energization command from the VCU, the BMS disconnects the relay and then checks the main and negative relays for adhesion. If |bus current| < 5A and |V3-V4| <= 3% * current battery voltage for 100ms, the main positive relay is considered to be stuck, and the BMS reports a main negative relay adhesion fault. If |V3-V4| > 3% * current battery voltage for 100ms, the main negative relay is considered to be in normal condition.

[0148] In this embodiment, under preset operating conditions, the target relay is first determined based on the vehicle status information. Then, the front-end voltage detection value and the rear-end voltage detection value of the target relay are obtained. Subsequently, the DC-BOX controller performs adhesion detection on the target relay based on the front-end voltage detection value, the rear-end voltage detection value, and the current battery voltage value. Compared to existing technologies where plug-in hybrid electric vehicles only have AC slow charging capabilities and lack DC fast charging capabilities, this charging method is suitable for home charging. Public charging stations are operational DC fast charging stations, making it inconvenient for electric vehicles with AC slow charging capabilities to charge outdoors. In this embodiment, DC fast charging functionality is achieved by adding a DC-BOX controller. Then, adhesion detection is performed on the target relay based on the front-end voltage detection value, the rear-end voltage detection value, and the current battery voltage value, thereby effectively detecting the relay status and protecting the high-voltage safety of the entire vehicle and the high-voltage safety of the fast charging port.

[0149] Other embodiments or specific implementations of the relay adhesion detection system of the present invention can be referred to the above-described method embodiments, and will not be repeated here.

[0150] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0151] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0152] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as read-only memory / random access memory, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0153] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A method for detecting relay adhesion, characterized in that, The relay adhesion detection method includes the following steps: Under preset operating conditions, a target relay is determined based on vehicle status information. The target relay is a main positive relay, a main negative relay, or a fast charging relay. Obtain the front-end voltage detection value and the rear-end voltage detection value of the target relay; The voltage difference of the target relay is determined based on the front-end voltage detection value and the rear-end voltage detection value of the target relay; a preset voltage threshold is determined based on the current battery voltage value and a percentage threshold; the voltage difference of the target relay and the preset voltage threshold are compared, and adhesion detection is performed based on the comparison result, wherein the BMS performs adhesion detection on the main positive relay or the main negative relay, and the DC-BOX performs adhesion detection on the fast charging relay; The step of determining the target relay based on vehicle status information under preset operating conditions includes: When the vehicle is powered on and the vehicle is in a wake-up state, the BMS receives a high-voltage command from the VCU and checks the connection status of the connector. If the connector is not connected, the BMS determines whether the target relay is a main positive relay or a main negative relay and performs adhesion detection. When the vehicle is powered on, if the DC-BOX detects that the charging gun is not plugged in and the battery is under high voltage, the DC-BOX will perform a fast charging relay sticking detection. When fast charging ends, if the DC-BOX detects that the charging gun is unplugged and the battery is not under high voltage, the DC-BOX will perform a fast charging relay sticking detection.

2. The method as described in claim 1, characterized in that, The step of comparing the voltage difference of the target relay with the preset voltage threshold and performing adhesion detection based on the comparison result further includes: Determine whether the voltage difference of the target relay is less than or equal to the preset voltage threshold; When the voltage difference of the target relay is less than or equal to the preset voltage threshold, the target relay is determined to be in a stuck state, and a stuck fault is reported for the target relay. When the voltage difference of the target relay is greater than the preset voltage threshold, the target relay is determined to be in a normal state.

3. The method as described in claim 2, characterized in that, After the step of performing adhesion detection on the target relay using a BMS or DC-BOX based on the front-end voltage detection value, the rear-end voltage detection value, and the current battery voltage value, the method further includes: Determine if the current vehicle speed is less than the preset speed; When the current vehicle speed is less than the preset vehicle speed, determine whether the target relay is stuck. If so, high voltage should be prevented from being applied to the battery, and a high voltage system fault should be indicated on the instrument panel.

4. The method as described in claim 1, characterized in that, The step of determining the target relay based on vehicle status information under preset operating conditions further includes: Under preset operating conditions, the high-voltage command information sent by the vehicle controller is obtained based on the vehicle status information. The preset operating conditions are high voltage or fast charging ending while driving. When the high-voltage command information is a low-voltage command information, the target relay operation is disconnected, and the target relay is either a main positive relay or a main negative relay.

5. The method as described in claim 4, characterized in that, The step of detecting adhesion of the target relay using the BMS based on the front-end voltage detection value of the target relay, the rear-end voltage detection value of the target relay, and the current battery voltage value further includes: The voltage difference between the main positive relay and the main negative relay is determined based on the front-end voltage detection value and the rear-end voltage detection value of the target relay. Determine the preset voltage threshold based on the current battery voltage value and percentage threshold; The main positive relay or main negative relay is detected for adhesion by BMS. When the bus current is less than the preset current and the voltage difference is less than or equal to the preset voltage threshold, the main positive relay or main negative relay is determined to be in an adhesion state, and the adhesion fault of the main positive relay or main negative relay is reported. When the voltage difference is greater than the preset voltage threshold, the main positive relay or the main negative relay is determined to be in a normal state.

6. A relay adhesion detection system, characterized in that, The relay adhesion detection system includes: The determination module is used to determine the target relay based on the vehicle status information under preset working conditions. The target relay is a main positive relay, a main negative relay, or a fast charging relay. The acquisition module is used to acquire the front-end voltage detection value and the rear-end voltage detection value of the target relay; The detection module is used to perform adhesion detection on the target relay through BMS or DC-BOX based on the front-end voltage detection value of the target relay, the rear-end voltage detection value of the target relay, and the current battery voltage value. The BMS performs adhesion detection on the main positive relay or the main negative relay, and the DC-BOX performs adhesion detection on the fast charging relay. The relay adhesion detection system implements the steps of the relay adhesion detection method as described in claim 1.

7. A relay adhesion detection device, characterized in that, The device includes: a memory, a processor, and a relay adhesion detection program stored in the memory and executable on the processor, the relay adhesion detection program being configured to implement the steps of the relay adhesion detection method as described in any one of claims 1 to 5.

8. A storage medium, characterized in that, The storage medium stores a relay adhesion detection program, which, when executed by a processor, implements the steps of the relay adhesion detection method as described in any one of claims 1 to 5.

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