Insulation fault detection method of high-voltage system, controller, detection system and vehicle

Abstract

The invention provides an insulation fault detection method of a high-voltage system, a controller, a detection system and a vehicle, and relates to the technical field of vehicle detection, and the method comprises the steps: obtaining a first insulation resistance value detected by a battery management system; determining whether the high-voltage system has an insulation fault according to the first insulation resistance value; if the high-voltage system has the insulation fault, controlling a contactor of a driving function high-voltage branch to be kept connected, and controlling a contactor of a non-driving function high-voltage branch to be disconnected; after the contactor of the non-driving function high-voltage branch is disconnected, a second insulation resistance value detected by the battery management system is obtained; according to the second insulation resistance value, determining whether the insulation fault disappears after the contactor of the non-driving function high-voltage branch is disconnected; and if the insulation fault disappears after the contactor of the non-driving function high-voltage branch circuit is disconnected, determining that the fault source of the insulation fault is the non-driving function high-voltage branch circuit. The position of the insulation fault is accurately determined, so that the safety of vehicle driving is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle detection, in particular to an insulation fault detection method of a high-voltage system, a controller, a detection system and a vehicle. BACKGROUND

[0002] With the wide application of new energy commercial vehicles in the fields of logistics, passenger transport and municipal administration, the safety and reliability of the high-voltage electrical system of the new energy commercial vehicles become the key factors affecting the operation efficiency and user trust of the vehicles. The high-voltage system usually includes multiple high-voltage components, and each component is connected to the high-voltage network of the vehicle through an independent high-voltage branch. In actual operation, the vehicle is long-term under complex working conditions such as vibration, humidity and large temperature difference, which easily causes the insulation performance of the high-voltage system to decrease, resulting in insulation faults.

[0003] At present, the insulation monitoring device based on the battery management system is generally used in commercial vehicles to detect the total insulation resistance value of the high-voltage system of the vehicle in real time. When the insulation resistance is detected to be lower than the preset safety threshold and lasts for a certain time, the vehicle controller determines that a serious insulation fault occurs, and immediately triggers the highest level of fault response mechanism.

[0004] However, the prior art can only determine that a serious insulation fault exists in the system, but cannot automatically identify the specific branch position where the fault occurs, resulting in that the maintenance personnel need to rely on experience to check item by item, which is time-consuming and low in efficiency. Whether the fault occurs in the non-critical function branch system or not, the high-voltage power of the vehicle is cut off, causing the vehicle to lose power instantaneously. For the vehicle that is performing a transport task, it is easy to cause the interruption of operation, the delay of goods and even the road safety hazard. SUMMARY

[0005] The purpose of the present application is to provide an insulation fault detection method of a high-voltage system, a controller, a detection system and a vehicle to accurately determine the insulation fault position, thereby improving the safety of vehicle driving, in view of the deficiencies in the prior art.

[0006] To achieve the above purpose, the technical solutions adopted by the embodiments of the present application are as follows: In a first aspect, an embodiment of the present application provides an insulation fault detection method of a high-voltage system, which comprises: A vehicle controller applied to a new energy vehicle, wherein the vehicle controller is connected to a battery management system of a high-voltage system in the new energy vehicle and contactors on each high-voltage branch in the high-voltage system; each high-voltage branch includes a driving function high-voltage branch and a non-driving function high-voltage branch, and the method comprises: Obtaining a first insulation resistance value detected by the battery management system; Determining whether an insulation fault occurs in the high-voltage system according to the first insulation resistance value; If an insulation fault occurs in the high-voltage system, the contactor of the travel function high-voltage branch is controlled to remain connected, and the contactor of the non-travel function high-voltage branch is controlled to be disconnected; After the contactor of the non-travel function high-voltage branch is disconnected, a second insulation resistance value detected by the battery management system is acquired; According to the second insulation resistance value, it is determined whether the insulation fault disappears after the contactor of the non-travel function high-voltage branch is disconnected; If the insulation fault disappears after the contactor of the non-travel function high-voltage branch is disconnected, it is determined that the fault source of the insulation fault is the non-travel function high-voltage branch.

[0007] Optionally, the travel function high-voltage branch includes a main drive motor branch, an auxiliary drive power supply branch, and a power system air conditioning branch. The control of the contactor of the travel function high-voltage branch to remain connected includes: The contactors of the main drive motor branch, the auxiliary drive power supply branch, and the power system air conditioning branch are all controlled to remain connected.

[0008] Optionally, the non-travel function high-voltage branch includes a fuel-electric system branch, a cab heater branch, and a cab air conditioner branch. The control of the contactor of the non-travel function high-voltage branch to be disconnected includes: The contactors of the fuel-electric system branch, the cab heater branch, and the cab air conditioner branch are controlled to be disconnected step by step. After the contactor of the non-travel function high-voltage branch is disconnected, the second insulation resistance value detected by the battery management system is acquired, including: After the contactor of each branch is disconnected, the second insulation resistance value of the corresponding branch detected by the battery management system is acquired. If the insulation fault disappears after the contactor of the non-travel function high-voltage branch is disconnected, it is determined that the fault source of the insulation fault is the non-travel function high-voltage branch. If the insulation fault disappears after the contactor of the corresponding branch is disconnected, it is determined that the fault source of the insulation fault is the corresponding branch.

[0009] Optionally, the control of the contactors of the fuel-electric system branch, the cab heater branch, and the cab air conditioner branch to be disconnected step by step includes: Before disconnecting the contactor of the current branch in the fuel-electric system branch, the cab heater branch, and the cab air conditioner branch, the device of the current branch is controlled to be turned off, and the feedback state of the device of the current branch is acquired. if the device feedback state of the current branch is the shutdown state, directly disconnecting the contactor of the current branch; if the device feedback state of the current branch is the startup state for a preset time length, disconnecting the contactor of the current branch when the preset time length arrives.

[0010] Optionally, the method further comprises: sending fault prompt information to an instrument panel, the fault prompt information being used to indicate that the non-critical component of the corresponding branch has a fault; sending the insulation fault code of the corresponding branch to a cloud platform.

[0011] Optionally, the method further comprises: if the insulation faults do not disappear after the contactors of all the non-driving function high-voltage branches are disconnected, determining that the fault source of the insulation faults is the driving function high-voltage branch.

[0012] Optionally, the method further comprises: sending an audible and visual alarm signal to prompt the driver to stop the vehicle; after the new energy vehicle is stopped, performing a high-voltage power-off process to disconnect all the contactors of the high-voltage system.

[0013] In a second aspect, another embodiment of the present application provides an insulation fault detection device of a high-voltage system, the device comprising: a first acquisition module configured to acquire a first insulation resistance value detected by a battery management system; a first determination module configured to determine whether the high-voltage system has an insulation fault according to the first insulation resistance value; a control module configured to control the contactor of the driving function high-voltage branch to remain connected and control the contactors of the non-driving function high-voltage branches to be disconnected if the high-voltage system has an insulation fault; a second acquisition module configured to acquire a second insulation resistance value detected by the battery management system after the contactors of the non-driving function high-voltage branches are disconnected; a second determination module configured to determine whether the insulation faults disappear after the contactors of the non-driving function high-voltage branches are disconnected according to the second insulation resistance value; a third determination module configured to determine that the fault source of the insulation faults is the non-driving function high-voltage branch if the insulation faults disappear after the contactors of the non-driving function high-voltage branches are disconnected.

[0014] In a third aspect, another embodiment of the present application provides a vehicle controller, comprising: a processor, a memory and a bus, the memory storing machine readable instructions executable by the processor, when the vehicle controller is running, the processor communicates with the memory through the bus, the processor executes the machine readable instructions to perform the steps of the insulation fault detection method of the high-voltage system according to any one of the first aspect.

[0015] In a fourth aspect, another embodiment of the present application provides a storage medium, the storage medium storing a computer program, when the computer program is run by a processor, the steps of the method according to any one of the first aspect are performed.

[0016] In a fifth aspect, another embodiment of the present application provides an insulation fault detection system of a high-voltage system, the insulation fault detection system comprising: a vehicle controller and a high-voltage system, the high-voltage system comprising: a power battery and a plurality of high-voltage branches, wherein the battery management system of the power battery is connected to the vehicle controller, the vehicle controller is further connected to the contactors on the plurality of high-voltage branches, and the power battery is electrically connected to the plurality of high-voltage branches. The vehicle controller is configured to perform the steps of the insulation fault detection method of the high-voltage system according to any one of the first aspect.

[0017] In a sixth aspect, another embodiment of the present application provides a new energy vehicle, characterized in that the new energy vehicle comprises a vehicle body and an insulation fault detection system arranged on the vehicle body, and the vehicle controller in the insulation fault detection system is configured to perform the steps of the insulation fault detection method of the high-voltage system according to any one of the first aspect.

[0018] The present application has the following beneficial effects: The application provides a high-voltage system insulation fault detection method, a controller, a detection system and a vehicle, obtains a first insulation resistance value detected by a battery management system; determines whether an insulation fault occurs in the high-voltage system according to the first insulation resistance value; if the insulation fault occurs in the high-voltage system, controls a contactor of a driving function high-voltage branch to remain connected and controls a contactor of a non-driving function high-voltage branch to be disconnected; obtains a second insulation resistance value detected by the battery management system after the contactor of the non-driving function high-voltage branch is disconnected; determines whether the insulation fault disappears after the contactor of the non-driving function high-voltage branch is disconnected according to the second insulation resistance value; and if the insulation fault disappears after the contactor of the non-driving function high-voltage branch is disconnected, determines that a fault source of the insulation fault is the non-driving function high-voltage branch. The application can realize intelligent positioning of a fault section without increasing hardware cost by preferentially keeping the contactor of the driving function related high-voltage branch closed after detecting a serious insulation fault, gradually disconnecting only the non-driving function branch, and judging the fault source in combination with changes of the front and rear insulation resistance values. On the basis of ensuring safety of personnel and the vehicle, operation interruption caused by whole vehicle power-off is avoided, the vehicle can still maintain normal driving capability if the fault source is from a non-critical system, and the economy and usability of the vehicle are improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0020] Figure 1 A flowchart of a high-voltage system insulation fault detection method provided by the embodiments of the application; Figure 2 A flowchart of determining on-off of a non-driving function high-voltage branch in the high-voltage system insulation fault detection method of the above step provided by the embodiments of the application; Figure 3 A flowchart of controlling disconnection of a contactor in the high-voltage system insulation fault detection method provided by the embodiments of the application; Figure 4 A flowchart of sending an insulation fault code in the high-voltage system insulation fault detection method provided by the embodiments of the application; Figure 5 A flowchart of disconnecting a high-voltage system in the high-voltage system insulation fault detection method provided by the embodiments of the application; Figure 6 A structural diagram of a high-voltage system insulation fault detection device provided by the embodiments of the application; Figure 7 A structural schematic diagram of an insulation fault detection device of a high-voltage system provided by an embodiment of the present application is provided. Figure 8 A structural schematic diagram of an insulation fault detection system provided by an embodiment of the present application is provided. Figure 9 A structural schematic diagram of a new energy vehicle provided by an embodiment of the present application is provided. DETAILED DESCRIPTION

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. It should be understood that the drawings in the present application merely serve the purpose of description and illustration, and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn according to the actual proportions. The flowcharts show the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowcharts can not be implemented in sequence, and the steps without logical context relationship can be reversed in sequence or implemented simultaneously. In addition, one or more other operations can be added to the flowcharts or one or more operations can be removed from the flowcharts under the guidance of the content of the present application.

[0022] In addition, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but merely represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0023] It should be noted that the term “comprising” will be used in the embodiments of the present application to indicate the presence of the features declared thereafter, but does not exclude the addition of other features.

[0024] To clearly describe the method provided by the embodiments of the present application, the insulation fault detection method of the high-voltage system provided by the embodiments of the present application will be described below with reference to multiple drawings. The method in the present application is applied to a vehicle controller of a new energy vehicle. The vehicle controller is connected to a battery management system of a high-voltage system in the new energy vehicle and contactors on each high-voltage branch in the high-voltage system. Each high-voltage branch includes a driving function high-voltage branch and a non-driving function high-voltage branch.

[0025] Figure 1 A flowchart of an insulation fault detection method of a high-voltage system provided by an embodiment of the present application is provided, asFigure 1 The method comprises the following steps of: Step 101, obtaining a first insulation resistance value detected by a battery management system.

[0026] The first insulation resistance is the insulation resistance between the positive terminal of the high-voltage system of the vehicle and the vehicle body ground. If the insulation between the positive terminal of the high-voltage system and the vehicle body fails, a leakage current loop is formed, resulting in system failure. An insulation detection circuit is arranged in the battery management system, and the first insulation resistance value is obtained through the insulation detection circuit.

[0027] Optionally, the insulation resistance of the vehicle is detected through the insulation detection circuit in the battery management system to obtain the insulation resistance value in a preset detection time period, and if the insulation resistance values in the preset detection time period are consistent, the insulation resistance value is taken as the first insulation resistance value.

[0028] Step 102, determining whether an insulation fault occurs in the high-voltage system according to the first insulation resistance value.

[0029] The insulation fault refers to that the first insulation resistance value is low, resulting in an increase in leakage current and affecting the safety of the vehicle.

[0030] Optionally, the first insulation resistance value is compared with an insulation resistance threshold value, and if the first insulation resistance value is smaller than the insulation resistance threshold value, it is determined whether an insulation fault occurs in the high-voltage system. The insulation resistance threshold value can be between 100 ohms and 500 ohms, and is determined according to the parameters of the vehicle.

[0031] Step 103, if an insulation fault occurs in the high-voltage system, the contactors of the high-voltage branches of the driving function are controlled to remain connected, and the contactors of the high-voltage branches of the non-driving function are controlled to be disconnected.

[0032] The high-voltage branches of the driving function include a plurality of branches related to the driving function, and each branch includes a plurality of electric equipment related to the driving function and a corresponding contactor. The high-voltage branches of the non-driving function include a plurality of high-voltage electric branches unrelated to the driving function of the vehicle, and each branch includes a plurality of electric equipment unrelated to the driving function and a corresponding contactor.

[0033] Optionally, if an insulation fault occurs in the high-voltage system, the contactors of the high-voltage branches of the driving function are controlled to remain connected, the contactors of the high-voltage branches of the non-driving function are controlled to be disconnected, and it is determined whether a fault occurs in the high-voltage branches of the non-driving function.

[0034] Step 104, obtaining a second insulation resistance value detected by the battery management system after the contactors of the high-voltage branches of the non-driving function are disconnected.

[0035] Optionally, after the contactor of the non-driving function high-voltage branch is disconnected, the insulation resistance of the vehicle is detected again by the insulation detection circuit in the battery management system, and an insulation resistance value in a preset detection time period is obtained. If the insulation resistance values in the preset detection time period are consistent, the insulation resistance value is taken as the second insulation resistance value.

[0036] Step 105: According to the second insulation resistance value, it is determined whether the insulation fault disappears after the contactor of the non-driving function high-voltage branch is disconnected.

[0037] Optionally, the second insulation resistance value is compared with an insulation resistance threshold value, and whether the insulation fault disappears after the contactor of the non-driving function high-voltage branch is disconnected is determined according to a comparison result.

[0038] Step 106: If the insulation fault disappears after the contactor of the non-driving function high-voltage branch is disconnected, it is determined that the fault source of the insulation fault is the non-driving function high-voltage branch.

[0039] Optionally, if the insulation fault disappears after the contactor of the non-driving function high-voltage branch is disconnected, that is, the second insulation resistance value is greater than the insulation resistance threshold value, it is indicated that the fault source of the insulation fault is the non-driving function high-voltage branch. If the fault source of the insulation fault is the non-driving function high-voltage branch, only the contactor of the non-driving function high-voltage branch is controlled to be disconnected, and the contactor of the driving function high-voltage branch is kept closed. When the insulation fault occurs in the non-driving function high-voltage branch during vehicle driving, the electrical equipment of the driving function high-voltage branch continues to operate, and the driving state of the vehicle is maintained.

[0040] In the embodiment of the present application, a first insulation resistance value detected by a battery management system is obtained; whether an insulation fault occurs in a high-voltage system is determined according to the first insulation resistance value; if the insulation fault occurs in the high-voltage system, a contactor of a driving function high-voltage branch is controlled to be kept connected, and a contactor of a non-driving function high-voltage branch is controlled to be disconnected; after the contactor of the non-driving function high-voltage branch is disconnected, a second insulation resistance value detected by the battery management system is obtained; whether the insulation fault disappears after the contactor of the non-driving function high-voltage branch is disconnected is determined according to the second insulation resistance value; and if the insulation fault disappears after the contactor of the non-driving function high-voltage branch is disconnected, it is determined that the fault source of the insulation fault is the non-driving function high-voltage branch. By preferentially keeping the contactor of the driving function high-voltage branch closed after a serious insulation fault is detected, and only gradually disconnecting the non-driving function branch, and by combining the changes of the insulation resistance values before and after the fault, the fault source is determined, so that intelligent positioning of the fault section can be realized without increasing the hardware cost. On the basis of ensuring the safety of personnel and vehicles, the operation interruption caused by the whole vehicle being powered off is avoided, the vehicle can still maintain normal driving capability if the fault source is from a non-critical system, and the economy and usability of the vehicle are improved.

[0041] On the basis of the above-mentioned embodiments, the driving function high-voltage branch includes: a main drive motor branch, an auxiliary drive power supply branch, and a power system air conditioning branch. The application also provides a process for controlling the connection of the driving function high-voltage branch in the insulation fault detection method of the high-voltage system, and the contactors of the driving function high-voltage branch are kept connected in step 103, including: The contactors of the main drive motor branch, the auxiliary drive power supply branch, and the power system air conditioning branch are all kept connected.

[0042] The main drive motor branch is the branch corresponding to the motor, including the motor and the corresponding contactor, and the motor is used to drive the new energy vehicle to move. The auxiliary drive power supply branch includes a DC / DC conversion branch, an air pump branch, and an oil pump branch. The DC / DC conversion branch is used to convert high-voltage electricity of the battery pack into low-voltage electricity to supply power to low-voltage electrical equipment in the vehicle, including a DC / DC and corresponding contactors and fuses; the air pump branch is used to control the vehicle to perform electric power-assisted braking, including an air pump and corresponding contactors and fuses; and the oil pump branch is used to control the vehicle to perform electric power-assisted steering, including an oil pump and corresponding contactors and fuses. The power system air conditioning branch is used to cool the power battery, including a power system air conditioner and corresponding fuses and contactors.

[0043] Optionally, the contactors of the main drive motor branch, the auxiliary drive power supply branch, and the power system air conditioning branch are all kept connected, so that the driving function of the vehicle is normal.

[0044] In the embodiments of the application, keeping the contactors of the main drive motor branch, the auxiliary drive power supply branch, and the power system air conditioning branch connected can ensure that the core driving function of the vehicle is not affected when an insulation fault occurs. At the same time of accurately isolating the non-critical fault branch, the power performance, the handling performance, and the thermal management capability of the vehicle are preserved, so that the vehicle still has safe and reliable basic driving performance in a fault state, unnecessary stopping is avoided, and the running availability and safety of the vehicle are improved.

[0045] On the basis of the above-mentioned embodiments, the non-driving function high-voltage branch includes: a fuel-electric system branch, a cab heater branch, and a cab air conditioner branch. The application also provides a process for determining the on-off of the non-driving function high-voltage branch in the insulation fault detection method of the high-voltage system, Figure 2 A process for determining the on-off of the non-driving function high-voltage branch in the insulation fault detection method of the high-voltage system provided in the embodiments of the application is shown in Figure 2 As shown in 103, the contactors of the non-driving function high-voltage branch are disconnected, including: Step 201, the contactors of the fuel-electric system branch, the cab heater branch, and the cab air conditioner branch are disconnected step by step.

[0046] The fuel cell system branch is used to provide high-voltage power supply support for the fuel cell system, and includes the fuel cell system and corresponding contactors and fuses. The cab heating branch is used to supply power to the cab heating device, and includes the cab heating system and corresponding contactors and fuses. The cab air conditioning branch is used to supply power to the air conditioning compressor and supporting components to achieve cabin refrigeration and dehumidification, and includes the cab air conditioning system and corresponding contactors and fuses.

[0047] Optionally, the contactors of the cab air conditioning branch, the cab heating branch and the fuel cell system branch are sequentially and gradually opened.

[0048] After the contactor of the non-driving function high-voltage branch is opened in the step 104, a second insulation resistance value detected by the battery management system is obtained, including: Step 202: After the contactor of each branch is opened, a second insulation resistance value of the corresponding branch detected by the battery management system is obtained.

[0049] Optionally, after the contactor of the cab air conditioning branch is opened, a second insulation resistance value of the cab air conditioning branch detected by the battery management system is obtained. If the second insulation resistance value of the cab air conditioning branch is less than the insulation resistance threshold value, the contactor of the cab air conditioning branch is closed, the contactor of the cab heating branch is opened, and a second insulation resistance value of the cab heating branch detected by the battery management system is obtained. If the second insulation resistance value of the cab heating branch is less than the insulation resistance threshold value, the contactor of the cab heating branch is closed, and the contactor of the fuel cell system branch is opened, and a second insulation resistance value of the fuel cell system branch detected by the battery management system is obtained.

[0050] If the insulation fault disappears after the contactor of the non-driving function high-voltage branch is opened in the step 105, it is determined that the fault source of the insulation fault is the non-driving function high-voltage branch, including: Step 203: If the insulation fault disappears after the contactor of the corresponding branch is opened, it is determined that the fault source of the insulation fault is the corresponding branch.

[0051] Optionally, if the second insulation resistance value of the corresponding branch is greater than or equal to the insulation resistance threshold value after the contactor of the corresponding branch is opened, it indicates that there is no insulation fault at this time, and it is determined that the fault source of the insulation fault is the corresponding branch.

[0052] For example, after the contactor of the cab air conditioning branch is opened, a second insulation resistance value of the cab air conditioning branch detected by the battery management system is obtained. If the second insulation resistance value of the cab air conditioning branch is greater than the insulation resistance threshold value, the cab air conditioning branch has an insulation fault, and at this time the insulation fault is a common insulation fault. Therefore, the contactor of the cab air conditioning branch is opened.

[0053] If the second insulation resistance value of the cab heater branch is greater than the insulation resistance threshold value, the cab heater branch has an insulation fault, and at this time, the insulation fault is a common insulation fault, and the contactor of the cab heater branch is controlled to be turned off.

[0054] If the second insulation resistance value of the fuel cell system branch is greater than the insulation resistance threshold value, the fuel cell system branch has an insulation fault, and at this time, the insulation fault is a common insulation fault, and the contactor of the fuel cell system branch is controlled to be turned off.

[0055] In the embodiment of the application, by gradually turning off the contactors of the fuel cell system branch, the cab heater branch and the cab air conditioning branch, and obtaining the second insulation resistance value detected by the battery management system after each time, the step-by-step isolation and fault response monitoring of the non-key high-voltage branch is realized, the specific source branch of the insulation fault can be located without interrupting the normal driving of the vehicle, the operation interruption problem caused by the overall power-off is avoided, the accuracy and maintenance direction of fault diagnosis are improved, the troubleshooting time is shortened, and the operation and maintenance cost is reduced.

[0056] On the basis of the above-mentioned embodiment, the application further provides a process of controlling the contactor to be turned off in the insulation fault detection method of the high-voltage system, Figure 3 A process diagram of controlling the contactor to be turned off in the insulation fault detection method of the high-voltage system provided by the embodiment of the application is shown in Figure 3 The contactors of the fuel cell system branch, the cab heater branch and the cab air conditioning branch are gradually turned off in step 201, which includes: Step 301, before turning off the contactor of the current branch in the fuel cell system branch, the cab heater branch and the cab air conditioning branch, the device of the current branch is controlled to be turned off, and the feedback state of the device of the current branch is obtained.

[0057] The device corresponding to the fuel cell system branch can be the air compressor, the hydrogen circulating pump, the water pump and other high-voltage auxiliary power supplies of the fuel cell stack. The device corresponding to the cab heater branch can be the PTC (Positive Temperature Coefficient Heater) heater, the heater water pump and the fan motor. The device corresponding to the cab air conditioning branch can be the high-voltage electric air conditioning compressor, the condensing fan and the air blower.

[0058] Optionally, before turning off the fuel cell system branch, the air compressor, the hydrogen circulating pump, the water pump and other high-voltage auxiliary power supplies of the fuel cell stack in the fuel cell system branch are controlled to be turned off. Before turning off the cab heater branch, the PTC heater, the heater water pump and the fan motor in the cab heater branch are controlled to be turned off. Before turning off the cab air conditioning branch, the high-voltage electric air conditioning compressor, the condensing fan and the air blower of the cab air conditioning branch are controlled to be turned off.

[0059] Step 302, if the device feedback state of the current branch is the shutdown state, directly disconnect the contactor of the current branch.

[0060] Optionally, if the device feedback state of the current branch is the shutdown state, it indicates that the power-off has no effect on the device of the current branch, and then the contactor of the current branch is directly disconnected.

[0061] Step 303, if the device feedback state of the current branch is continuously in the startup state within a preset time length, the contactor of the current branch is disconnected when the preset time length arrives.

[0062] Optionally, if the device feedback state of the current branch is continuously in the startup state within a preset time length, it indicates that the device of the current branch may be faulty and unable to shut down, and then the contactor of the current branch is disconnected when the preset time length arrives.

[0063] In the embodiments of the present application, before the non-critical high-voltage branch is disconnected, the device is preferentially instructed to soft-shutdown and waits for its feedback state, if the shutdown is confirmed, the contactor is normally disconnected, if the timeout is not responded, the contactor is forcibly disconnected, which has safety and fault tolerance capability. Both the orderliness and safety of high-voltage disconnection operation are guaranteed, the risk of device damage is avoided, and the diagnosis process is prevented from being stuck due to communication failure or response delay of individual subsystems, so that the insulation fault positioning process can be reliably promoted, the intelligent level of the system is improved, the robustness is enhanced, and the safety, efficiency and high availability are unified.

[0064] On the basis of the above-mentioned embodiments, the present application further provides a process for sending an insulation fault code in a high-voltage system insulation fault detection method, Figure 4 A process for sending an insulation fault code in a high-voltage system insulation fault detection method provided by the embodiments of the present application is shown in Figure 4 On the basis of the above-mentioned steps 301-303, the method further comprises: Step 401, sending fault prompt information to the instrument panel, the fault prompt information being used to indicate that there is a fault in the non-critical component of the corresponding branch.

[0065] Optionally, if the non-driving function high-voltage branch has an insulation fault, the fault prompt information is sent to the instrument panel, the fault prompt information being used to indicate that there is a fault in the non-critical component of the corresponding branch, so that the driver or vehicle management personnel can maintain the vehicle based on the fault prompt information.

[0066] For example, if the insulation fault is the cab air conditioner branch, the corresponding fault prompt information is output as "system fault, air conditioner function disabled".

[0067] Step 402, sending the insulation fault code of the corresponding branch to the cloud platform.

[0068] The insulation fault code can include: vehicle identification, fault level, fault time, information of the fault branch, and information of the fault equipment on the fault branch, and the fault level is used to indicate a serious insulation fault or a common insulation fault, and the fault time is the time when the fault is detected.

[0069] Optionally, the insulation fault code of the corresponding branch is sent to the cloud platform, and the vehicle identification, the fault level, the fault time, the information of the fault branch, and the information of the fault equipment on the fault branch are determined through the insulation fault code.

[0070] In the embodiment of the application, the fault prompt information is sent to the instrument panel, and the fault prompt information is used to indicate that there is a fault in the non-critical component of the corresponding branch; and the insulation fault code of the corresponding branch is sent to the cloud platform. Through the sending of the fault prompt information to the instrument panel and the sending of the insulation fault code of the corresponding branch to the cloud platform, the dual response mechanism of local reminding and remote monitoring is realized, which can timely inform the driver that there is a fault in the non-critical component, avoid misoperation or panic parking, ensure the vehicle to continue driving under safe conditions, and improve the operation continuity; and the accurate fault positioning result can be uploaded to the cloud in real time to support remote diagnosis, active dispatching and spare parts preparation, shorten the maintenance cycle, and reduce the operation and maintenance cost.

[0071] On the basis of the above-mentioned embodiment, the application further provides a process for determining a fault source in a high-voltage system insulation fault detection method, which comprises the following steps on the basis of the above-mentioned steps 101-106: If the insulation fault does not disappear after the contactors of all non-driving function high-voltage branches are turned off, it is determined that the fault source of the insulation fault is the driving function high-voltage branch.

[0072] In the embodiment of the application, the reliable identification of the key high-voltage circuit fault is realized by the exclusion method, and on the premise of not relying on additional sensors, the existing contactor segmentation control logic and insulation resistance change trend are used to accurately lock the fault range to the main drive motor branch and the auxiliary drive power supply branch.

[0073] On the basis of the above-mentioned embodiment, the application further provides a process for turning off the high-voltage system in a high-voltage system insulation fault detection method, Figure 5 A process for turning off the high-voltage system in a high-voltage system insulation fault detection method provided in the embodiment of the application is shown in FIG. Figure 5 On the basis of the above-mentioned step of determining that the fault source of the insulation fault is the driving function high-voltage branch if the insulation fault does not disappear after the contactors of all non-driving function high-voltage branches are turned off, the method further comprises the following steps: Step 501, a sound and light alarm signal is sent to prompt the driver to stop the vehicle.

[0074] The sound and light alarm signal is a fault indicator light of the vehicle system and a text prompt. The text prompt can be a serious insulation fault, please park safely, and contact after-sales maintenance.

[0075] Optionally, when the fault source of the insulation fault is the running function high-voltage branch, it indicates that the vehicle continues to run may cause a safety fault, then the fault indicator light of the vehicle system is lit and the text prompt is output, prompting the driver to slow down and park under safe conditions.

[0076] Step 502, after the new energy vehicle is parked, a high-voltage power-off process is performed to disconnect all contactors of the high-voltage system.

[0077] Optionally, after the new energy vehicle is parked, a high-voltage power-off process is performed to disconnect all contactors of the running function high-voltage branch and the non-running function high-voltage branch of the high-voltage system.

[0078] In the embodiments of the present application, a sound and light alarm signal is sent to prompt the driver to park, and a high-voltage power-off process is performed after the vehicle is parked, realizing the orderly linkage of safety warning and safety power-off, avoiding the risk of out-of-control in emergency conditions on the premise of ensuring personnel safety; the sound and light alarm timely reminds the driver that there is a serious safety hazard, guiding him to choose a suitable place to park under controllable conditions, preventing a secondary accident caused by sudden power-off in high-speed running or dangerous areas; all high-voltage contactors are disconnected after the vehicle is parked, which not only meets the functional safety logic, but also completely isolates the fault source, preventing the risk of electric shock or fire caused by deteriorating insulation.

[0079] Based on the same inventive concept, the embodiments of the present application also provide an insulation fault detection device for a high-voltage system corresponding to the insulation fault detection method of the high-voltage system. Since the principle of the device in the embodiments of the present application solves the problem similar to the above-mentioned insulation fault detection method of the high-voltage system of the embodiments of the present application, the implementation of the device can be referred to the implementation of the method, and the repeated parts will not be described again.

[0080] Figure 6 A structure diagram of a high-voltage system insulation fault detection device provided in the embodiments of the present application, the device comprises: The first acquisition module 601 is configured to acquire the first insulation resistance value detected by the battery management system. The first determination module 602 is configured to determine whether the high-voltage system has an insulation fault according to the first insulation resistance value. The control module 603 is configured to control the contactor of the running function high-voltage branch to remain connected and control the contactor of the non-running function high-voltage branch to be disconnected if the high-voltage system has an insulation fault. The second acquisition module 604 is configured to acquire the second insulation resistance value detected by the battery management system after the contactor of the non-running function high-voltage branch is disconnected. The second determination module 605 is configured to determine whether the insulation fault disappears after the contactor of the non-driving function high-voltage branch is disconnected according to the second insulation resistance value. The third determination module 606 is configured to determine that the fault source of the insulation fault is the non-driving function high-voltage branch if the insulation fault disappears after the contactor of the non-driving function high-voltage branch is disconnected.

[0081] In a possible implementation, the driving function high-voltage branch includes a main drive motor branch, an auxiliary drive power supply branch, and a power system air conditioner branch; and the control module 603 is specifically configured to control the contactors of the main drive motor branch, the auxiliary drive power supply branch, and the power system air conditioner branch to remain connected.

[0082] In a possible implementation, the non-driving function high-voltage branch includes a fuel-electric system branch, a cab heater branch, and a cab air conditioner branch; and the control module 603 is specifically configured to control the contactors of the fuel-electric system branch, the cab heater branch, and the cab air conditioner branch to be disconnected gradually. In a possible implementation, the second acquisition module 604 is specifically configured to acquire the second insulation resistance value of the corresponding branch detected by the battery management system each time the contactor of one branch is disconnected. In a possible implementation, the second determination module 604 is specifically configured to determine that the fault source of the insulation fault is the corresponding branch if the insulation fault disappears after the contactor of the corresponding branch is disconnected.

[0083] In a possible implementation, the control module 603 is specifically configured to control a device of a current branch to be closed and acquire a feedback state of the device of the current branch before the contactor of the current branch in the fuel-electric system branch, the cab heater branch, and the cab air conditioner branch is disconnected. If the feedback state of the device of the current branch is a shutdown state, the contactor of the current branch is directly disconnected. If the feedback state of the device of the current branch is a startup state for a preset time length, the contactor of the current branch is disconnected when the preset time length arrives.

[0084] In a possible implementation, the control module 603 is further configured to send fault prompt information to an instrument panel, where the fault prompt information is used to indicate that a non-critical component of the corresponding branch has a fault. The control module 603 is further configured to send an insulation fault code of the corresponding branch to a cloud platform.

[0085] In a possible implementation, the third determination module 606 is further configured to determine that the fault source of the insulation fault is the driving function high-voltage branch if the insulation fault does not disappear after the contactors of all the non-driving function high-voltage branches are disconnected.

[0086] In a possible implementation, the third determining module 606 is further configured to send an audible and visual alarm signal to prompt the driver to stop the vehicle. After the new energy vehicle is parked, a high-voltage power-off process is performed to disconnect all contactors of the high-voltage system.

[0087] The description of the processing procedure of each module in the device and the interaction procedure between the modules can refer to the related description in the above method embodiments, and will not be described in detail here.

[0088] The vehicle controller 700 provided in the embodiment of the present application includes a processor 701, a memory 702, and optionally a bus 703. The memory 702 stores machine readable instructions executable by the processor 701. When the vehicle controller 700 is running, the processor 701 communicates with the memory 702 through the bus 703. The machine readable instructions are executed by the processor 701 to perform the steps of the above high-voltage system insulation fault detection method. Figure 7 As shown in the structural schematic diagram of the insulation fault detection system provided in the embodiment of the present application, the insulation fault detection system 800 includes a vehicle controller 700 and a high-voltage system 801. The high-voltage system 801 includes a power battery 8011 and a plurality of high-voltage branches 8012. The battery management system 80111 of the power battery 8011 is connected to the vehicle controller 700. The vehicle controller 700 is further connected to contactors on the plurality of high-voltage branches 8012. The power battery 8011 is electrically connected to the plurality of high-voltage branches 8012. Figure 7 The vehicle controller 700 is configured to perform the steps of the above high-voltage system insulation fault detection method.

[0089] The embodiment of the present application further provides a computer readable storage medium, and the computer readable storage medium stores a computer program. When the computer program is run by a processor, the steps of the above high-voltage system insulation fault detection method are performed.

[0090] The other embodiment of the present application further provides a high-voltage system insulation fault detection system, Figure 8 As shown in the structural schematic diagram of the insulation fault detection system provided in the embodiment of the present application, the insulation fault detection system 800 includes a vehicle controller 700 and a high-voltage system 801. The high-voltage system 801 includes a power battery 8011 and a plurality of high-voltage branches 8012. The battery management system 80111 of the power battery 8011 is connected to the vehicle controller 700. The vehicle controller 700 is further connected to contactors on the plurality of high-voltage branches 8012. The power battery 8011 is electrically connected to the plurality of high-voltage branches 8012. Figure 8 The vehicle controller 700 is configured to perform the steps of the above high-voltage system insulation fault detection method. The plurality of high-voltage branches 8012 include a driving function high-voltage branch and a non-driving function high-voltage branch. The driving function high-voltage branch includes a main drive motor branch, an auxiliary drive power supply branch, and a power system air conditioner branch.

[0091]

[0092] ​The main drive motor branch includes two contactors, diodes, resistors and a motor control unit (MCU), and the MCU is powered to control the motor. The two contactors are controlled to realize the on-off of the main drive motor branch.

[0093] The auxiliary drive power supply branch includes two contactors, diodes, resistors, a DC / DC conversion branch, an air pump branch and an oil pump branch. The DC / DC conversion branch includes a fuse and a DC-DC converter, and the DC-DC converter converts high voltage into low voltage to supply power to the DC / DC. The air pump branch includes a fuse and a DC-AC, and the DC-AC supplies power to the air pump. The oil pump branch includes a fuse and a DC-AC, and the DC-AC supplies power to the oil pump. The two contactors are controlled to realize the on-off of the auxiliary drive power supply branch. The power system air conditioner branch includes two contactors, diodes, resistors and fuses, and the two contactors are controlled to realize the on-off of the power system air conditioner branch.

[0094] The non-running function high-voltage branch includes a fuel-electric system branch, a cab heater branch and a cab air conditioner branch. The fuel-electric system branch includes two contactors, diodes, resistors and fuses, and the two contactors are controlled to realize the on-off of the fuel-electric system branch. The cab heater branch includes two contactors, diodes, resistors and fuses, and the two contactors are controlled to realize the on-off of the cab heater branch. The cab air conditioner branch includes two contactors, diodes, resistors and fuses, and the two contactors are controlled to realize the on-off of the cab air conditioner branch.

[0095] Another embodiment of the present application also provides a new energy vehicle, Figure 9 A structural schematic diagram of a new energy vehicle provided by the embodiment of the present application is shown in Figure 9 The new energy vehicle includes a vehicle body 91 and an insulation fault detection system 800 arranged on the vehicle body. A vehicle controller 700 in the insulation fault detection system 800 is used to execute the steps of the insulation fault detection method of the high-voltage system.

[0096] Those skilled in the art can clearly understand the specific working process of the system and the device described above for the convenience and brevity of description, and the corresponding process in the method embodiment can be referred to, and the present application will not be described again. In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented by other ways. The device embodiments described above are only schematic, for example, the division of the modules is only a logical function division, and the actual implementation can have another division, for example, a plurality of modules or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed each other can be indirect coupling or communication connection through some communication interfaces, devices or modules, which can be electrical, mechanical or other forms.

[0097] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. When the functions are realized in the form of software functional units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or say the parts that make contributions to the prior art or parts of the technical solutions can be embodied in the form of software products, which are stored in a storage medium and include a plurality of instructions for making a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in each embodiment of the present application. The foregoing 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 program code storage media.

[0098] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application.

Claims

1. A method for detecting insulation faults in a high-voltage system, characterized in that, A vehicle controller for use in new energy vehicles, wherein the vehicle controller is connected to the battery management system of the high-voltage system in the new energy vehicle, and the contactors on each high-voltage branch of the high-voltage system; Each of the aforementioned high-voltage branches includes: a high-voltage branch for driving function and a high-voltage branch for non-driving function, and the method includes: Obtain the first insulation resistance value detected by the battery management system; Based on the first insulation resistance value, determine whether an insulation fault has occurred in the high-voltage system; If an insulation fault occurs in the high-voltage system, the contactor controlling the high-voltage branch of the driving function remains connected, and the contactor controlling the high-voltage branch of the non-driving function disconnects. After the contactor of the non-driving function high-voltage branch is disconnected, the second insulation resistance value detected by the battery management system is obtained. Based on the second insulation resistance value, determine whether the insulation fault disappears after the contactor of the non-driving high-voltage branch is disconnected; If the insulation fault disappears after the contactor of the non-driving high-voltage branch is disconnected, then the source of the insulation fault is determined to be the non-driving high-voltage branch.

2. The method according to claim 1, characterized in that, The high-voltage branch circuit for driving function includes: main drive motor branch circuit, auxiliary drive power supply branch circuit, and power system air conditioning branch circuit. The contactor of the high-voltage branch controlling the driving function remains connected, including: The contactors controlling the main drive motor branch, the auxiliary drive power supply branch, and the power system air conditioning branch are all kept connected.

3. The method according to claim 1, characterized in that, The non-driving function high-voltage branch circuit includes: the fuel-electric system branch circuit, the cab heating branch circuit, and the cab air conditioning branch circuit; The contactor controlling the disconnection of the non-driving function high-voltage branch includes: The contactors controlling the fuel-electric system branch, the cab heating branch, and the cab air conditioning branch are gradually disconnected; After the contactor in the non-driving function high-voltage branch is disconnected, the second insulation resistance value detected by the battery management system is obtained, including: For each branch contactor disconnected, the second insulation resistance value of the corresponding branch detected by the battery management system is obtained; If the insulation fault disappears after the contactor of the non-driving high-voltage branch is disconnected, then the source of the insulation fault is determined to be the non-driving high-voltage branch, including: If the insulation fault disappears after the contactor in the corresponding branch is disconnected, then the source of the insulation fault is determined to be the corresponding branch.

4. The method according to claim 3, characterized in that, The contactors controlling the fuel-electric system branch, the cab heating branch, and the cab air conditioning branch are gradually disconnected, including: Before disconnecting the contactor of the current branch of the fuel-electric system branch, the cab heating branch, and the cab air conditioning branch, control the equipment of the current branch to shut down and obtain the feedback status of the equipment of the current branch. If the device feedback status of the current branch is "off", then the contactor of the current branch is directly disconnected. If the device feedback status of the current branch remains in the powered-on state for a preset time period, the contactor of the current branch will be disconnected when the preset time period is reached.

5. The method according to claim 3, characterized in that, The method further includes: Send a fault warning message to the dashboard, the fault warning message being used to indicate that there is a fault in a non-critical component of the corresponding branch; Send the insulation fault code of the corresponding branch to the cloud platform.

6. The method according to claim 1, characterized in that, The method further includes: If the insulation fault does not disappear after the contactors of all the non-driving function high-voltage branches are disconnected, then the source of the insulation fault is determined to be the driving function high-voltage branch.

7. The method according to claim 6, characterized in that, The method further includes: It emits an audible and visual alarm signal to prompt the driver to stop. After the new energy vehicle stops, a high-voltage power-off procedure is performed to disconnect all contactors of the high-voltage system.

8. A vehicle controller, characterized in that, The vehicle controller includes a processor and a memory, the memory storing machine-readable instructions executable by the processor. When the computer device is running, the processor executes the machine-readable instructions to perform the steps of the insulation fault detection method for a high-voltage system as described in any one of claims 1 to 7.

9. An insulation fault detection system for a high-voltage system, characterized in that, The insulation fault detection system includes a vehicle controller and a high-voltage system. The high-voltage system includes a power battery and multiple high-voltage branches. The battery management system of the power battery is connected to the vehicle controller. The vehicle controller is also connected to contactors on the multiple high-voltage branches. The power battery is electrically connected to the multiple high-voltage branches. The vehicle controller is used to perform the steps of the insulation fault detection method for the high-voltage system according to any one of claims 1-7.

10. A new energy vehicle, characterized in that, The new energy vehicle includes a vehicle body and an insulation fault detection system installed on the vehicle body. The vehicle controller in the insulation fault detection system is used to execute the steps of the insulation fault detection method of the high voltage system according to any one of claims 1-7.

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