Vehicle controller, control method and electric vehicle

Abstract

The invention discloses a vehicle controller, a control method and an electric vehicle, and relates to the technical field of new energy automobiles. The electric vehicle comprises a power battery, a direct-current conversion circuit and a plurality of high-voltage assemblies, the power battery is used for supplying power to a bus capacitor of each high-voltage assembly through a power supply switch, and the direct-current conversion circuit is used for carrying out voltage reduction conversion on direct current output by the power battery to supply power to a low-voltage battery; and controlling the direct-current conversion circuit to receive power supplied by the low-voltage battery and outputting current to the plurality of high-voltage assemblies through a bus capacitor of the direct-current conversion circuit. And after the direct-current conversion circuit stops outputting the current, when the difference value between the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the direct-current conversion circuit is smaller than a preset value, the power supply switch is controlled to be switched on. According to the scheme, before high-voltage power-on of the electric vehicle, continuous detection of the high-voltage loop can be achieved, the risk of electric shock is avoided, and the safety of the whole vehicle is improved.

Description

Technical Field

[0001] This application relates to the field of electric vehicles, and more specifically, to a vehicle controller, control method, and electric vehicle. Background Technology

[0002] With the increasing popularity of electric vehicles, their safety is receiving growing attention. Electric vehicles power their drive motors and other high-voltage loads via high-voltage battery output current. During operation, exposed high-voltage circuits may occur, increasing the risk of accidental electric shock. Therefore, high-voltage interlock loop (HVIL) testing is necessary. HVIL is a core safety protection mechanism for the high-voltage system of new energy vehicles. Exposed live parts in the high-voltage circuit are interlocked with the high-voltage system's power-on; that is, if any live parts are exposed, the system must be de-energized, and when the system is energized, no live parts should be exposed in the circuit. Electric vehicles are tested for the connection status of high-voltage components, connectors, and wiring to ensure that the high-voltage system is only energized when all components are reliably connected and there is no risk of personnel contact. If any abnormality is detected, such as a disconnected connector or damaged wiring, the high-voltage power supply is immediately cut off to prevent electric shock accidents. Current HVIL testing primarily detects the integrity of the high-voltage circuit through low-voltage signals, requiring additional low-voltage wiring harnesses for signal transmission, resulting in high system complexity and testing costs.

[0003] Therefore, how to effectively detect the continuity of high-voltage circuits is a problem that needs to be solved. Summary of the Invention

[0004] This application provides a vehicle controller, control method, and electric vehicle. Before the high-voltage system is powered on, the high-voltage circuit is pre-charged by a DC-DC converter circuit. The connection status of each high-voltage assembly is determined based on the voltage difference between the bus capacitor voltage of each high-voltage assembly and the bus capacitor voltage of the DC-DC converter circuit. Before the electric vehicle is powered on, the continuity of the high-voltage circuit can be detected, avoiding the risk of electric shock and improving the safety of the entire vehicle.

[0005] In a first aspect, this application provides a vehicle controller for an electric vehicle. The electric vehicle includes a power battery, a DC-DC converter circuit, and multiple high-voltage assemblies. The power battery supplies power to the bus capacitor of each high-voltage assembly via a power supply switch. The DC-DC converter circuit steps down the DC power output from the power battery to supply power to the battery at a lower voltage. Before the power supply switch is closed, the vehicle controller controls the DC-DC converter circuit to receive power from the low-voltage battery and output current to the multiple high-voltage assemblies through the bus capacitor of the DC-DC converter circuit. After the DC-DC converter circuit stops outputting current, when the voltage difference between the bus capacitor of each high-voltage assembly and the bus capacitor of the DC-DC converter circuit is less than a preset value, the power supply switch is closed.

[0006] The DC-DC converter circuit is used to connect to both the power battery and the low-voltage battery. It steps down the high-voltage DC output from the power battery to a low-voltage DC output to charge the low-voltage battery. The DC-DC converter circuit also has a reverse pre-charge function; it receives power from the low-voltage battery and outputs current to the high-voltage bus, thereby charging the bus capacitors of multiple high-voltage assemblies. The low-voltage battery consists of one or more cells. Its voltage is lower than the output voltage of the power battery. The bus capacitors of the DC-DC converter circuit are connected to the high-voltage DC bus, receiving current from the low-voltage battery and charging it to output current to the high-voltage assemblies via the high-voltage DC bus.

[0007] The high-voltage assembly in this application refers to an electrical component connected to and receiving power from the power battery. The high-voltage assembly includes, but is not limited to, powertrain components, air conditioning compressors, on-board chargers, and positive temperature coefficient (PTC) heaters. Each high-voltage assembly includes a bus capacitor connected to a high-voltage DC bus. The bus capacitor filters and regulates the input voltage, temporarily stores or releases energy, and buffers energy. It receives power and supplies power to the components within the high-voltage assembly. The high-voltage circuit refers to a circuit formed by connecting multiple high-voltage assemblies in parallel with the power battery. The high-voltage circuit connects the power battery and multiple high-voltage assemblies. The continuity detection of the high-voltage circuit refers to detecting whether there is an open circuit fault in the high-voltage circuit. When an open circuit fault occurs in the high-voltage circuit, there may be a risk of electric shock.

[0008] Multiple high-voltage assemblies in an electric vehicle are connected to a power battery via a power supply switch. The power supply switch controls whether the electric vehicle is energized with high voltage. In this application, "energizing with high voltage" means the power supply switch is closed, and the power battery outputs current to the multiple high-voltage assemblies. "Discharging with high voltage" or "not energizing with high voltage" means the power supply switch is open, and the connection between the power battery and the multiple high-voltage assemblies is broken.

[0009] High-voltage interlocking is a safety protection mechanism for the high-voltage system of electric vehicles. The high-voltage circuit of an electric vehicle connects the powertrain and multiple high-voltage assemblies. During the use of electric vehicles, high-voltage circuits may become exposed, increasing the risk of accidental electric shock. Therefore, high-voltage interlocking testing is necessary. The interlocking between exposed live parts of the high-voltage circuit and the high-voltage system's power-on state means that if any live parts are exposed, the system needs to be de-energized; when the system is energized, no live parts should be exposed in the circuit. Electric vehicles are tested for the connection status of high-voltage components, connectors, and wiring to ensure that the high-voltage system is only energized when all components are reliably connected and there is no risk of personnel contact. If any abnormality is detected, such as a disconnected connector or damaged wiring, the high-voltage power supply is immediately cut off to prevent electric shock accidents. Currently, high-voltage interlocking mainly involves adding a low-voltage circuit connected to the high-voltage assembly, arranged separately from the high-voltage wiring harness, to check the integrity of the high-voltage circuit based on the model of the low-voltage circuit. However, this requires additional low-voltage wiring harnesses, resulting in higher costs.

[0010] When the electric vehicle detects the user's intention to apply high voltage, it controls the power switch to close, thereby connecting the power battery to multiple high-voltage assemblies. The vehicle controller performs a continuity check of the high-voltage circuit before closing the power switch. Before the power switch closes, the vehicle controller controls the DC-DC converter to receive power from the low-voltage battery and output current to multiple high-voltage assemblies through the DC-DC converter's bus capacitor. Through the DC-DC converter's reverse pre-charge function, the low-voltage battery charges the high-voltage assemblies in the high-voltage circuit. Each high-voltage assembly includes a bus capacitor. The low-voltage battery outputs current to multiple high-voltage assemblies through the DC-DC converter's bus capacitor, thus increasing the voltage of the bus capacitor in each high-voltage assembly, temporarily storing energy. After the DC-DC converter stops outputting current, the voltage of the bus capacitor in each high-voltage assembly and the voltage of the bus capacitor in the DC-DC converter are detected. When the difference between the voltage of the bus capacitor in each high-voltage assembly and the voltage of the bus capacitor in the DC-DC converter is less than a preset value, it indicates that the high-voltage circuit is intact, and each high-voltage assembly's bus capacitor is normally receiving current from the low-voltage battery. At this point, the vehicle is allowed to apply high voltage. The vehicle controller closes the power supply switch, connecting the power battery and multiple high-voltage assemblies.

[0011] The preset values ​​are pre-calibrated based on actual vehicle experiments and / or model calculations, or are pre-set by comprehensively considering device performance and line losses.

[0012] According to the solution of this application, reverse pre-charging is performed through a DC-DC converter circuit, and current is output from the low-voltage battery to the high-voltage circuit. High voltage is only allowed when the voltage difference between the bus capacitor voltage of the high-voltage assembly and the bus capacitor voltage of the DC-DC converter circuit is less than a preset value. The connection status of the high-voltage circuit is determined by the voltage difference. No additional low-voltage wiring harness is required, which reduces costs and simplifies the hardware structure. Furthermore, the continuity detection of the high-voltage circuit is realized before the electric vehicle is powered on, avoiding the risk of electric shock and improving the safety of the entire vehicle.

[0013] In conjunction with the first aspect, in some implementations of the first aspect, the vehicle controller is specifically used to control the DC-DC converter to output current through the bus capacitor of the DC-DC converter to charge the bus capacitor of each high-voltage assembly to a preset voltage before the power supply switch is closed. When the voltage of the bus capacitor of the DC-DC converter reaches the preset voltage, the controller controls the DC-DC converter to stop outputting current.

[0014] The vehicle controller controls the DC-DC converter circuit to charge the bus capacitor of each high-voltage assembly to a preset voltage. To avoid the risk of electric shock, this preset voltage is less than or equal to a safe voltage, typically 60V. During the process of controlling the DC-DC converter circuit to receive power from the low-voltage battery and output current to multiple high-voltage assemblies through its bus capacitor, the voltage of both the DC-DC converter bus capacitor and the high-voltage assembly bus capacitor gradually increases. The vehicle controller monitors the voltage of either the DC-DC converter bus capacitor or the high-voltage assembly bus capacitor in real time. The voltage of the bus capacitor of each high-voltage assembly can be obtained by detecting the voltage at the controller's self-test port for each high-voltage assembly. When the voltage of the DC-DC converter bus capacitor rises to the preset voltage, the controller stops the reverse pre-charging of the DC-DC converter circuit and stops outputting current to the high-voltage circuit.

[0015] A current high-voltage interlocking scheme detects the continuity of the high-voltage circuit by comparing the output voltage of the power battery with the port voltages of each high-voltage assembly after the electric vehicle is powered on. However, since this detection can only be performed after high-voltage power is applied, and the high voltage in the high-voltage circuit means there is a possibility of the high-voltage circuit being disconnected during the power-on process, posing a safety risk of personnel coming into contact with high voltage. The vehicle controller in this application, however, pre-charges the high-voltage circuit to a lower preset voltage via a DC-DC converter circuit before high-voltage power is applied, i.e., before the power switch is closed, thereby enabling the continuous detection of the high-voltage circuit.

[0016] According to the solution of this application, the high-voltage circuit is pre-charged to a preset voltage by a DC-DC converter circuit. Under the condition of a lower preset voltage, the connection status of each high-voltage assembly is determined by the voltage difference between the bus capacitor voltage of the high-voltage assembly and the voltage at the port of the DC-DC converter circuit. The continuity detection of the high-voltage circuit can be realized before the electric vehicle is powered on, avoiding the risk of electric shock and improving the safety of the whole vehicle.

[0017] In conjunction with the first aspect, in some implementations of the first aspect, the vehicle controller is also used to control the power supply switch to remain open when the difference between the voltage of the bus capacitor of any one of the multiple high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter is greater than or equal to a preset value after the DC-DC converter stops outputting current.

[0018] After the DC-DC converter circuit stops outputting current, the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit are detected. If the difference between the voltage of the bus capacitor of any high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit is greater than or equal to a preset value, that is, if the voltage of the bus capacitor of any high-voltage assembly is abnormally low, it indicates that there is a disconnection fault in the high-voltage circuit. The bus capacitor of any high-voltage assembly cannot normally receive the current output from the low-voltage battery, and in this case, high voltage is not allowed to be applied to the vehicle. The vehicle controller keeps the power supply switch off and does not allow the power supply switch to be closed.

[0019] According to the solution of this application, reverse pre-charging is performed through a DC-DC converter circuit, and current is output from a low-voltage battery to a high-voltage circuit. When the voltage difference between the bus capacitor of any high-voltage assembly and the bus capacitor of the DC-DC converter circuit is greater than or equal to a preset value, high voltage is not allowed. The connection status of the high-voltage circuit is determined by the voltage difference. No additional low-voltage wiring harness is needed, which reduces costs and simplifies the hardware structure. Furthermore, the continuity detection of the high-voltage circuit is realized before the electric vehicle is powered on, avoiding the risk of electric shock and improving the safety of the entire vehicle.

[0020] In conjunction with the first aspect, in some implementations of the first aspect, the vehicle controller is also used to control the power supply switch to remain open after the DC-DC converter circuit stops outputting current, when the difference between the voltage of the bus capacitors of the multiple high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit is greater than or equal to a preset value.

[0021] After the DC-DC converter circuit stops outputting current, the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit are detected. If the difference between the voltage of the bus capacitors of multiple high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit is greater than or equal to a preset value, it indicates that there is a disconnection fault in the high-voltage circuit, and the DC-DC converter circuit may also have a disconnection fault. When the DC-DC converter circuit has a disconnection fault, the bus capacitor of the DC-DC converter circuit can still receive current from the low-voltage battery through the reverse pre-charge function, but it cannot output current to the high-voltage circuit. Therefore, the bus capacitors of the high-voltage assemblies cannot receive the current output by the DC-DC converter circuit. At this time, high voltage is not allowed to be applied to the vehicle. The vehicle controller keeps the power supply switch off and does not allow the power supply switch to be closed.

[0022] According to the solution of this application, reverse pre-charging is performed through a DC-DC converter circuit, and current is output from the low-voltage battery to the high-voltage circuit. When the voltage difference between the bus capacitors of multiple high-voltage assemblies and the bus capacitor of the DC-DC converter circuit is greater than or equal to a preset value, high voltage is not allowed. The connection status of the high-voltage circuit is determined by the voltage difference. There is no need to add an additional low-voltage wiring harness, which reduces costs, simplifies the hardware structure, and realizes the continuity detection of the high-voltage circuit before the electric vehicle is powered on, avoiding the risk of electric shock and improving the safety of the whole vehicle.

[0023] In conjunction with the first aspect, in some implementations of the first aspect, the vehicle controller is also used to control the power supply switch to close when the voltage difference between the bus capacitor of the DC-DC converter circuit and the bus capacitor of each high-voltage assembly and the preset voltage is less than a preset value after the DC-DC converter circuit stops outputting current.

[0024] After the DC-DC converter circuit stops outputting current, the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit are detected. When the difference between the voltage of the bus capacitor of the DC-DC converter circuit and the bus capacitor of each high-voltage assembly and the preset voltage is less than the preset value, that is, the voltage of the bus capacitor of the DC-DC converter circuit and the bus capacitor of each high-voltage assembly has basically reached the preset voltage, it indicates that the high-voltage circuit is complete and the bus capacitor of each high-voltage assembly is receiving the current output from the low-voltage battery normally. At this time, the vehicle is allowed to operate at high voltage. The vehicle controller controls the power supply switch to close, connecting the power battery and multiple high-voltage assemblies.

[0025] According to the solution of this application, reverse pre-charging is performed through a DC-DC converter circuit, and the low-voltage battery outputs current to the high-voltage circuit. When the voltage of the bus capacitors of multiple high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit both reach the preset voltage, high voltage is allowed. The connection status of the high-voltage circuit is determined by the difference between the voltage and the preset voltage. No additional low-voltage wiring harness is required, which reduces costs and simplifies the hardware structure. Furthermore, the continuity detection of the high-voltage circuit is realized before the electric vehicle is powered on, avoiding the risk of electric shock and improving the safety of the entire vehicle.

[0026] In conjunction with the first aspect, in some implementations of the first aspect, the vehicle controller is also used to control the power supply switch to remain open after the DC-DC converter circuit stops outputting current, when the difference between the voltage of the bus capacitor of the DC-DC converter circuit or the bus capacitor of any one of the multiple high-voltage assemblies and a preset voltage is greater than or equal to a preset value.

[0027] After the DC-DC converter circuit stops outputting current, the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit are detected. If the difference between the voltage of the bus capacitor of the DC-DC converter circuit or the bus capacitor of any high-voltage assembly and the preset voltage is greater than or equal to the preset value, it indicates that there is a disconnection fault in the high-voltage circuit. If the bus capacitor of the DC-DC converter circuit or any high-voltage assembly whose voltage does not reach the preset voltage has a disconnection fault, then the entire vehicle is not allowed to apply high voltage. The vehicle controller keeps the power supply switch off and does not allow the power supply switch to be closed.

[0028] According to the solution of this application, reverse pre-charging is performed through a DC-DC converter circuit, and current is output from the low-voltage battery to the high-voltage circuit. When the voltage of the bus capacitor of multiple high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit do not reach the preset voltage, high voltage is not allowed. The connection status of the high-voltage circuit is determined by the difference between the voltage and the preset voltage. There is no need to add an additional low-voltage wiring harness, which reduces costs and simplifies the hardware structure. Furthermore, the continuity detection of the high-voltage circuit is realized before the electric vehicle is powered on, avoiding the risk of electric shock and improving the safety of the entire vehicle.

[0029] In conjunction with the first aspect, in some implementations of the first aspect, the vehicle controller is specifically used to control the closing of the power supply switch, and the power battery outputs current to the bus capacitors of multiple high-voltage assemblies to increase the voltage of the bus capacitors of each high-voltage assembly.

[0030] After the DC-DC converter circuit stops outputting current, the vehicle controller performs a high-voltage interlock detection based on the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit. If the high-voltage circuit is detected to be intact, the entire vehicle is allowed to access the high-voltage circuit. When controlling the electric vehicle to access the high-voltage circuit, the vehicle controller controls the power supply switch to close, thereby connecting the power battery to multiple high-voltage assemblies. The power battery outputs current to the bus capacitors of the multiple high-voltage assemblies to supply power to each high-voltage assembly, and at this time, the voltage of the bus capacitor of each high-voltage assembly increases.

[0031] During the high-voltage circuit continuity test, the bus capacitor of the high-voltage assembly is charged by the low-voltage battery through a DC-DC converter circuit. The power supply switch is not closed, and the voltage in the high-voltage circuit is low, resulting in a low risk of electric shock and high safety. After the high-voltage circuit continuity test is completed, the power supply switch is closed only after the test results allow power-on. The bus capacitor of the high-voltage assembly is then directly powered by the power battery, and the voltage in the high-voltage circuit rises to the operating voltage. Although the voltage is high, the safety after power-on is ensured because the continuity of the high-voltage circuit has already been verified.

[0032] According to the solution in this application, the continuity of the high-voltage circuit is detected at a lower voltage before the electric vehicle is powered on, thereby avoiding the risk of electric shock and improving the safety of the entire vehicle.

[0033] In conjunction with the first aspect, in some implementations of the first aspect, the vehicle controller is further configured to control the power supply switch to remain open and report a first fault information when the difference between the voltage of the bus capacitor of any one of the multiple high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit is greater than or equal to a preset value. The first fault information is used to indicate that any one of the high-voltage assemblies has failed.

[0034] After the DC-DC converter circuit stops outputting current, if the voltage difference between the bus capacitor of any high-voltage assembly and the bus capacitor of the DC-DC converter circuit is greater than or equal to a preset value, it indicates that a high-voltage assembly has an open circuit fault. At this time, the entire vehicle is not allowed to receive high voltage. The vehicle controller keeps the power supply switch open, preventing it from closing, and simultaneously reports the first fault information, alerting the user that the electric vehicle has a fault requiring repair. The first fault information indicates that any high-voltage assembly with a voltage difference between its bus capacitor and the bus capacitor of the DC-DC converter circuit greater than or equal to a preset value has an open circuit fault. Because the voltage difference between the bus capacitor of this high-voltage assembly and the bus capacitor of the DC-DC converter circuit is large, while the voltage differences between the bus capacitors of other high-voltage assemblies and the bus capacitor of the DC-DC converter circuit are small, it indicates that this high-voltage assembly may have an open circuit fault and cannot normally receive the current output from the DC-DC converter circuit.

[0035] According to the solution in this application, reverse pre-charging is achieved through a DC-DC converter circuit, and current is output from the low-voltage battery to the high-voltage circuit. The connection status of the high-voltage circuit is determined by the voltage difference, which high-voltage assembly has a disconnection fault. While prohibiting the application of high voltage, the fault information is promptly reported to remind the user to carry out maintenance, avoiding the risk of electric shock, facilitating fault analysis and troubleshooting, and effectively improving the safety of the entire vehicle.

[0036] In conjunction with the first aspect, in some implementations of the first aspect, the vehicle controller is further configured to control the power supply switch to remain open and report a second fault information when the voltage difference between the bus capacitors of multiple high-voltage assemblies and the bus capacitor of the DC-DC converter circuit is greater than or equal to a preset value. The second fault information is used to indicate that a fault has occurred in the DC-DC converter circuit.

[0037] After the DC-DC converter circuit stops outputting current, if the voltage difference between the bus capacitors of multiple high-voltage assemblies and the bus capacitor of the DC-DC converter circuit is greater than or equal to a preset value, it indicates that there is an open circuit fault in the DC-DC converter circuit. At this time, high voltage is not allowed to be applied to the vehicle. The vehicle controller keeps the power supply switch open, preventing it from closing, and simultaneously reports a second fault message, alerting the user that the electric vehicle has a fault requiring repair. The second fault message indicates an open circuit fault in the DC-DC converter circuit. Since the voltage difference between the bus capacitors of multiple high-voltage assemblies and the bus capacitor of the DC-DC converter circuit is significant, and the probability of all high-voltage assemblies experiencing an open circuit fault simultaneously is very low, it is more likely that there is an open circuit fault in the DC-DC converter circuit, preventing the bus capacitors of other high-voltage assemblies from receiving the current output from the DC-DC converter circuit.

[0038] According to the solution in this application, reverse pre-charging is achieved through a DC-DC converter circuit, and current is output from the low-voltage battery to the high-voltage circuit. The connection status of the high-voltage circuit is determined by the voltage difference, which can quickly identify the location of the high-voltage circuit disconnection fault. While prohibiting the application of high voltage, the fault information is promptly reported to remind the user to carry out maintenance, avoiding the risk of electric shock, facilitating fault analysis and troubleshooting, and effectively improving the safety of the entire vehicle.

[0039] In conjunction with the first aspect, in some implementations of the first aspect, the preset voltage is less than the voltage output by the power battery.

[0040] The output voltage of a power battery is typically high, such as 400 V or 800 V. After the power switch is closed, the voltage in the high-voltage circuit is as high as the output voltage of the power battery, increasing the risk of electric shock. Before the power switch is closed, the vehicle controller controls the DC-DC converter circuit to charge the bus capacitor of each high-voltage assembly to a preset voltage. To avoid the risk of electric shock, this preset voltage is less than or equal to the safe voltage, which is typically 60 V.

[0041] For example, the preset voltage is 48 V.

[0042] According to the solution of this application, the high-voltage circuit is pre-charged to a preset voltage by a DC-DC converter circuit. Under the condition of a lower preset voltage, the connection status of each high-voltage assembly is determined by the voltage difference between the bus capacitor voltage of the high-voltage assembly and the voltage at the port of the DC-DC converter circuit. The continuity detection of the high-voltage circuit can be realized before the electric vehicle is powered on, avoiding the risk of electric shock and improving the safety of the whole vehicle.

[0043] In conjunction with the first aspect, in some implementations of the first aspect, the vehicle controller is specifically used to control the DC-DC converter circuit to receive power from the low-voltage battery and output current to the multiple high-voltage assemblies through the bus capacitor of the DC-DC converter circuit when it receives a start command for the electric vehicle, the start command being used to instruct the power battery to supply power to multiple high-voltage assemblies before the power supply switch is closed.

[0044] Before each start-up of an electric vehicle, a continuity test of the high-voltage circuit is required. When the vehicle controller receives the start command of the electric vehicle, before the power supply switch is closed, it controls the DC-DC converter circuit to receive power from the low-voltage battery and outputs current to multiple high-voltage assemblies through the bus capacitor of the DC-DC converter circuit to perform a continuity test of the high-voltage circuit.

[0045] In another implementation, when the electric vehicle key approaches the electric vehicle or the vehicle detects the user's approach, even without receiving a start command, the vehicle controller performs continuity checks on the high-voltage circuit. Before the power switch is closed, it controls the DC-DC converter to receive power from the low-voltage battery and output current to multiple high-voltage assemblies through the DC-DC converter's bus capacitor. After the DC-DC converter stops outputting current, when the voltage difference between the bus capacitor of each high-voltage assembly and the bus capacitor of the DC-DC converter is less than a preset value, the power switch is closed.

[0046] According to the solution in this application, a high-voltage circuit continuity test is performed before each high-voltage connection to the electric vehicle, ensuring the integrity of the high-voltage circuit, avoiding the risk of electric shock, and improving the safety of the electric vehicle. Performing a high-voltage circuit continuity test when the user intends to connect to high voltage can effectively shorten the power-on process and improve the user experience.

[0047] Secondly, this application provides a control method for an electric vehicle. The control method detects the connection status of the electric vehicle's power battery to multiple high-voltage assemblies. The power battery supplies power to the bus capacitor of each high-voltage assembly via a power supply switch. The electric vehicle includes a DC-DC converter circuit, which steps down the DC power output from the power battery to supply power to the battery at a lower voltage. Before the power supply switch is closed, the control method controls the DC-DC converter circuit to receive power from the low-voltage battery and outputs current through its bus capacitor to charge the bus capacitor of each high-voltage assembly to a preset voltage. When the voltage of the bus capacitor of the DC-DC converter circuit reaches the preset voltage, the control method stops the DC-DC converter circuit from outputting current. After the DC-DC converter circuit stops outputting current, when the difference between the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit is less than a preset value, the control method closes the power supply switch.

[0048] In conjunction with the second aspect, in some implementations of the second aspect, the control method further includes, after the DC-DC converter circuit stops outputting current, if the difference between the voltage of the bus capacitor of any one of the multiple high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit is greater than or equal to a preset value, controlling the power supply switch to remain open and reporting a first fault information, the first fault information being used to indicate that any one of the high-voltage assemblies has failed. Alternatively, if the difference between the voltage of the bus capacitors of the multiple high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit is greater than or equal to a preset value, controlling the power supply switch to remain open and reporting a second fault information, the second fault information being used to indicate that the DC-DC converter circuit has failed.

[0049] Thirdly, this application provides a vehicle controller for an electric vehicle. The electric vehicle includes a power battery, an on-board charger, and multiple high-voltage assemblies. The power battery supplies power to the bus capacitor of each high-voltage assembly via a power supply switch. The on-board charger receives AC power and charges the power battery via the power supply switch. Before the on-board charger charges the power battery and the power supply switch is closed, the vehicle controller controls the on-board charger to receive AC power and output current to the multiple high-voltage assemblies through its output port. After the on-board charger stops outputting current, when the difference between the voltage of the bus capacitor of each high-voltage assembly and the voltage at the output port is less than a preset value, the controller controls the power supply switch to close so that the on-board charger charges the power battery.

[0050] An on-board charger is used to charge the power battery of an electric vehicle. It connects to an AC power source and then to the power battery via a power switch. The on-board charger receives AC power from the AC source, converts it to DC power, and charges the power battery through its output port. The on-board charger includes a power factor correction circuit and a resonant converter circuit. The power factor correction circuit adjusts the power factor of the input AC power to ensure efficient energy transfer between the AC source and the power battery. The resonant converter circuit converts the DC power output from the power factor correction circuit and charges the power battery. The resonant converter circuit includes a primary-side rectifier circuit, a resonant cavity, and a secondary-side rectifier circuit. The primary-side rectifier circuit receives the DC power output from the power factor correction circuit, rectifies it, and then inputs it into the resonant cavity. The secondary-side rectifier circuit receives the current output from the resonant cavity, rectifies it, and then inputs the current into the high-voltage DC bus through its output port.

[0051] When an electric vehicle is charging its power battery, the power switch is closed, and the connection between the power battery and the high-voltage assembly is established. Therefore, it is also necessary to perform continuity testing on the high-voltage circuit. Electric vehicles must check the connection status of high-voltage components, connectors, and wiring to ensure that the high-voltage system is energized only when all components are reliably connected and there is no risk of human contact. If any abnormality is detected, such as a disconnected connector or damaged wiring, the high-voltage power supply must be immediately cut off to prevent electric shock accidents.

[0052] Before the on-board charger charges the power battery and the power supply switch is closed, that is, after the on-board charger is connected to the DC power supply, the electric vehicle is about to start charging the power battery. Before the power supply switch is closed, the high-voltage circuit continuity is detected. The vehicle controller controls the on-board charger to receive the power supply from the AC power supply and output current to multiple high-voltage assemblies through the output port. Thus, the on-board charger converts the AC power output from the AC power supply into DC power and charges the bus capacitors of multiple high-voltage assemblies in the high-voltage circuit.

[0053] After the on-board charger stops outputting current, if the voltage difference between the bus capacitor of each high-voltage assembly and the voltage at the output port is less than a preset value, it indicates that the high-voltage circuit is intact and each bus capacitor of the high-voltage assembly is normally receiving the current output from the on-board charger. At this time, the entire vehicle is allowed to operate at high voltage. The control power supply switch is then closed to allow the on-board charger to charge the power battery.

[0054] It should be understood that, since an AC power supply is required to pre-charge the high-voltage circuit, the vehicle controller can only perform the above control in the scenario where the electric vehicle is AC charged.

[0055] According to the solution in this application, the AC power output from the AC power supply is converted into DC power by the on-board charger and output current to the high-voltage circuit. When the voltage difference between the bus capacitor voltage of the high-voltage assembly and the bus capacitor voltage of the DC-DC converter is less than a preset value, the power supply switch is controlled to be turned on. The connection status of the high-voltage circuit is determined by the voltage difference. There is no need to add an additional low-voltage wiring harness, which reduces costs and simplifies the hardware structure. Furthermore, the continuity detection of the high-voltage circuit is realized before the electric vehicle is powered on, avoiding the risk of electric shock and improving the safety of the entire vehicle.

[0056] In conjunction with the third aspect, in some implementations of the third aspect, the vehicle controller is specifically used to receive AC power from the on-board charger before the power supply switch is closed, and to output current through the output port to charge the bus capacitor of each high-voltage assembly to a preset voltage. When the voltage at the output port reaches the preset voltage, the controller controls the on-board charger to stop outputting current.

[0057] In conjunction with the third aspect, in some implementations of the third aspect, the vehicle controller is also used to control the power supply switch to remain open when the difference between the voltage of the bus capacitor of any one of the multiple high-voltage assemblies and the voltage of the output port is greater than or equal to a preset value after the on-board charger stops outputting current.

[0058] In conjunction with the third aspect, in some implementations of the third aspect, the vehicle controller is also used to control the power supply switch to remain open after the on-board charger stops outputting current, when the difference between the voltage of the bus capacitors of multiple high-voltage assemblies and the voltage of the output port is greater than or equal to a preset value.

[0059] In conjunction with the third aspect, in some implementations of the third aspect, the vehicle controller is also used to control the power supply switch to close when the difference between the voltage of the output port and the bus capacitor of each high-voltage assembly and the preset voltage is less than the preset value after the on-board charger stops outputting current.

[0060] In conjunction with the third aspect, in some implementations of the third aspect, the vehicle controller is also used to control the power supply switch to remain open when the difference between the voltage of the bus capacitor of the output port or any one of the high voltage assemblies and the preset voltage is greater than or equal to the preset value after the on-board charger stops outputting current.

[0061] In conjunction with the third aspect, in some implementations of the third aspect, the vehicle controller is also used to control the power supply switch to remain open and report a third fault information when the difference between the voltage of the bus capacitor of any one of the multiple high-voltage assemblies and the voltage of the output port is greater than or equal to a preset value. The third fault information is used to indicate that any one of the high-voltage assemblies has failed.

[0062] In conjunction with the third aspect, in some implementations of the third aspect, the vehicle controller is also used to control the power supply switch to remain open and report a fourth fault information when the difference between the voltage of the bus capacitors of multiple high-voltage assemblies and the voltage of the output port is greater than or equal to a preset value. The fourth fault information is used to indicate that a fault has occurred in the DC-DC converter circuit.

[0063] In conjunction with the third aspect, in some implementations of the third aspect, the preset voltage is lower than the voltage output by the power battery.

[0064] Fourthly, this application provides a control method for an electric vehicle. The control method detects the connection status of the electric vehicle's power battery and multiple high-voltage assemblies before AC charging the power battery. The power battery supplies power to the bus capacitor of each high-voltage assembly via a power supply switch. The electric vehicle includes an on-board charger that receives AC power and charges the power battery via the power supply switch. The control method includes controlling the on-board charger to receive AC power and output current through its output port to charge the bus capacitor of each high-voltage assembly to a preset voltage before the on-board charger charges the power battery and the power supply switch is closed. When the voltage at the output port reaches the preset voltage, the on-board charger stops outputting current. After the on-board charger stops outputting current, when the difference between the voltage of the bus capacitor of each high-voltage assembly and the voltage at the output port is less than a preset value, the power supply switch is closed to allow the on-board charger to charge the power battery.

[0065] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the control method further includes controlling the power supply switch to remain open and reporting a third fault information when the difference between the voltage of the bus capacitor of any one of the multiple high-voltage assemblies and the voltage at the output port is greater than or equal to a preset value. The third fault information is used to indicate that any one of the high-voltage assemblies has failed. Alternatively, when the difference between the voltage of the bus capacitor of all multiple high-voltage assemblies and the voltage at the output port is greater than or equal to a preset value, the power supply switch is controlled to remain open and a fourth fault information is reported. The fourth fault information is used to indicate that the DC-DC converter circuit has failed.

[0066] Fifthly, this application provides an electric vehicle including a power battery, multiple high-voltage assemblies, and a vehicle controller as described in the first aspect and its various implementations or the third aspect and its various implementations, wherein the multiple high-voltage assemblies include a powertrain for receiving power from the power battery to drive the electric vehicle.

[0067] Other beneficial effects can be found in the description of the first aspect, and will not be repeated here. Attached Figure Description

[0068] Figure 1 This is a schematic diagram of the architecture of an electric vehicle provided in an embodiment of this application; Figure 2 This is a schematic diagram of the high-voltage circuit topology of an electric vehicle provided in an embodiment of this application; Figure 3 This is a schematic diagram of a vehicle controller provided in an embodiment of this application; Figure 4 This is a schematic flowchart of an electric vehicle control method provided in an embodiment of this application; Figure 5 This is a schematic diagram of another vehicle controller provided in an embodiment of this application; Figure 6 This is a schematic flowchart of another electric vehicle control method provided in the embodiments of this application. Detailed Implementation

[0069] The technical solutions in this application will now be described in conjunction with the accompanying drawings. The detailed descriptions and drawings of the following embodiments are used to exemplarily illustrate the principles of this application, but should not be used to limit the scope of this application; that is, this application is not limited to the described embodiments.

[0070] With the increasing popularity of electric vehicles 10, their safety is receiving more and more attention. The high-voltage interlock of the electric vehicle 10 is a safety protection mechanism for its high-voltage system. The high-voltage circuit of the electric vehicle 10 connects the powertrain 30 and multiple high-voltage assemblies. During the use of the electric vehicle 10, the high-voltage circuit may become exposed, increasing the risk of accidental electric shock. Therefore, high-voltage interlock testing is necessary. The high-voltage circuit's exposed live parts are interlocked with the high-voltage system's power-on; that is, if any live parts are exposed, the system needs to be de-energized, but when the system is energized, no live parts in the circuit must be exposed. The electric vehicle 10 checks the connection status of high-voltage components, connectors, and wiring to ensure that the high-voltage system is only energized when all components are reliably connected and there is no risk of personnel contact. If any abnormality is detected, such as a disconnected connector or damaged wiring, the high-voltage power supply is immediately cut off to prevent electric shock accidents.

[0071] Current high-voltage interlocking mainly involves adding a low-voltage circuit to the high-voltage assembly, which is then arranged separately from the high-voltage wiring harness. This allows the integrity of the high-voltage circuit to be detected based on the model of the low-voltage circuit. However, this requires additional low-voltage wiring harnesses, resulting in higher costs.

[0072] Based on the above problems, this application provides a vehicle controller 70, a control method, and an electric vehicle 10. Before the high-voltage system is powered on, the high-voltage circuit is precharged by the DC-DC converter circuit 40. The connection status of each high-voltage assembly is determined based on the voltage difference between the bus capacitor voltage of each high-voltage assembly and the bus capacitor voltage of the DC-DC converter circuit 40. Before the electric vehicle 10 is powered on, the continuity of the high-voltage circuit can be detected, avoiding the risk of electric shock and improving the safety of the whole vehicle.

[0073] Figure 1 This is a schematic diagram of the architecture of the electric vehicle 10 provided in the embodiments of this application.

[0074] like Figure 1 As shown, the electric vehicle 10 includes four wheels, a power battery 20, a low-voltage battery 60, a DC-DC converter circuit 40, and multiple high-voltage assemblies.

[0075] Multiple high-voltage assemblies include, but are not limited to, the powertrain 30, the on-board charger 50, the air conditioning compressor, and the positive temperature coefficient (PTC) heater (not all shown in the figure). During the charging process of the electric vehicle 10, the on-board charger 50 receives AC power and converts it to DC power to charge the power battery 20. During the operation of the electric vehicle 10, the powertrain 30 receives DC power from the power battery 20 and outputs torque to drive the four wheels.

[0076] Figure 2 This is a schematic diagram of the topology of a high-voltage circuit 10 in an electric vehicle. (Example:) Figure 2As shown, the high-voltage circuit refers to a circuit formed by connecting multiple high-voltage assemblies in parallel with the power battery 20. The high-voltage circuit is used to connect the power battery 20 and the multiple high-voltage assemblies. The high-voltage circuit includes a powertrain 30 drive circuit and an on-board charger 50 circuit. The on-board charger 50 circuit receives AC power and charges the power battery 20, while the powertrain 30 drive circuit receives power from the power battery 20 and supplies power to the drive motor. In one embodiment, the high-voltage circuit also includes an air conditioning compressor drive circuit and a PTC power circuit. The compressor drive circuit drives the air conditioning compressor of the electric vehicle 10, and the PTC power circuit supplies power to the thermistor.

[0077] The DC-DC converter circuit 40 is used to connect to the power battery 20 and the low-voltage battery 60. The DC-DC converter circuit 40 is used to step down the high-voltage DC output from the power battery 20 to a low-voltage DC to charge the low-voltage battery 60. The DC-DC converter circuit 40 also has a reverse pre-charge function; it receives power from the low-voltage battery 60 and outputs current to the high-voltage bus, thereby charging the bus capacitors of multiple high-voltage assemblies.

[0078] Figure 3 This is a schematic diagram of a vehicle controller 70 provided in an embodiment of this application.

[0079] The vehicle controller 70 provided in this application may be a vehicle controller, a battery management system (BMS) controller, a DC-DC converter circuit 40 controller, or a controller for other high-voltage assemblies, or it may be other controllers with processing capabilities.

[0080] like Figure 3 As shown, the electric vehicle 10 includes a power battery 20, a DC-DC converter circuit 40, and multiple high-voltage assemblies. The power battery 20 supplies power to the bus capacitor of each high-voltage assembly through a power supply switch 21. The DC-DC converter circuit 40 is used to step down the DC power output from the power battery 20 and convert it to power the low-voltage battery 60.

[0081] The vehicle controller 70 controls the DC-DC converter 40 to receive power from the low-voltage battery 60 and output current to multiple high-voltage assemblies through the bus capacitor of the DC-DC converter 40 before the power supply switch 21 is closed. After the DC-DC converter 40 stops outputting current, the power supply switch 21 is controlled to close when the difference between the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter 40 is less than a preset value.

[0082] Multiple high-voltage assemblies of the electric vehicle 10 are connected to the power battery 20 via a power supply switch 21. The power supply switch 21 is used to control whether the electric vehicle 10 is energized with high voltage. In this application, "energizing the electric vehicle 10 with high voltage" means that the power supply switch 21 is closed, and the power battery 20 outputs current to the multiple high-voltage assemblies. "De-energizing the electric vehicle 10 with high voltage" or "not energizing the electric vehicle 10 with high voltage" means that the power supply switch 21 is in the open state, and the connection between the power battery 20 and the multiple high-voltage assemblies is disconnected.

[0083] The high-voltage interlock of the electric vehicle 10 is a safety protection mechanism for its high-voltage system. The high-voltage circuit of the electric vehicle 10 connects the powertrain 30 and multiple high-voltage assemblies. During the use of the electric vehicle 10, the high-voltage circuit may become exposed, increasing the risk of accidental electric shock. Therefore, high-voltage interlock testing is necessary. The high-voltage circuit's exposed live parts are interlocked with the high-voltage system's power-on; that is, if any live parts are exposed, the system needs to be de-energized, and when the system is energized, no live parts in the circuit should be exposed. The electric vehicle 10 detects the connection status of high-voltage components, connectors, and wiring to ensure that the high-voltage system is only energized when all components are reliably connected and there is no risk of personnel contact. If any abnormality is detected, such as a disconnected connector or damaged wiring, the high-voltage power supply is immediately cut off to prevent electric shock accidents. Currently, high-voltage interlocks are mainly achieved by adding low-voltage circuits connected to the high-voltage assemblies, arranged separately from the high-voltage wiring harness, thereby detecting the integrity of the high-voltage circuit based on the model of the low-voltage circuit. However, this requires additional low-voltage wiring harnesses, resulting in higher costs.

[0084] When the electric vehicle 10 detects that the user intends to access high voltage, it controls the power supply switch 21 to close, thereby connecting the power battery 20 to multiple high-voltage assemblies. The vehicle controller 70 performs continuity detection of the high-voltage circuit before the power supply switch 21 closes. Before the power supply switch 21 closes, the vehicle controller 70 controls the DC-DC converter 40 to receive power from the low-voltage battery 60 and output current to multiple high-voltage assemblies through the bus capacitor of the DC-DC converter 40. Through the reverse pre-charge function of the DC-DC converter 40, the low-voltage battery 60 charges the high-voltage assemblies in the high-voltage circuit. Each high-voltage assembly includes a bus capacitor. The low-voltage battery 60 outputs current to multiple high-voltage assemblies through the bus capacitor of the DC-DC converter 40, thereby increasing the voltage of the bus capacitor in each high-voltage assembly, and the bus capacitor temporarily stores energy. After the DC-DC converter circuit 40 stops outputting current, the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit 40 are detected. When the difference between the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit 40 is less than a preset value, it indicates that the high-voltage circuit is complete and the bus capacitor of each high-voltage assembly is receiving the current output from the low-voltage battery 60 normally. At this time, the entire vehicle is allowed to operate at high voltage. The vehicle controller 70 controls the power supply switch 21 to close, connecting the power battery 20 and multiple high-voltage assemblies.

[0085] According to the solution of this application, the DC-DC converter circuit 40 performs reverse pre-charging, and the low-voltage battery 60 outputs current to the high-voltage circuit. High voltage is only allowed when the voltage difference between the bus capacitor voltage of the high-voltage assembly and the bus capacitor voltage of the DC-DC converter circuit 40 is less than a preset value. The connection status of the high-voltage circuit is determined by the voltage difference. There is no need to add an additional low-voltage wiring harness, which reduces costs and simplifies the hardware structure. Furthermore, the continuity detection of the high-voltage circuit is realized before the electric vehicle 10 is powered on, avoiding the risk of electric shock and improving the safety of the entire vehicle.

[0086] In one embodiment, the vehicle controller 70 is specifically configured to, when receiving a start command from the electric vehicle 10, instruct the power battery 20 to supply power to multiple high-voltage assemblies, control the DC-DC converter 40 to receive power from the low-voltage battery 60 and output current to the multiple high-voltage assemblies through the bus capacitor of the DC-DC converter 40 before the power supply switch 21 is closed.

[0087] Before each start-up of the electric vehicle 10, a continuity test of the high-voltage circuit is required. When the vehicle controller 70 receives the start command of the electric vehicle 10, before the power supply switch 21 is closed, it controls the DC-DC converter circuit 40 to receive power from the low-voltage battery 60 and outputs current to multiple high-voltage assemblies through the bus capacitor of the DC-DC converter circuit 40 to perform a continuity test of the high-voltage circuit.

[0088] In another implementation, when the key to the electric vehicle 10 approaches the electric vehicle 10 or when a user is detected approaching the vehicle, even without receiving a start command, the vehicle controller 70 performs continuity detection of the high-voltage circuit. Before the power supply switch 21 is closed, it controls the DC-DC converter 40 to receive power from the low-voltage battery 60 and output current to multiple high-voltage assemblies through the bus capacitor of the DC-DC converter 40. After the DC-DC converter 40 stops outputting current, when the difference between the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter 40 is less than a preset value, it controls the power supply switch 21 to close.

[0089] In one embodiment, the vehicle controller 70 is specifically used to control the power supply switch 21 to close, and the power battery 20 outputs current to the bus capacitors of multiple high-voltage assemblies to increase the voltage of the bus capacitors of each high-voltage assembly.

[0090] After the DC-DC converter circuit 40 stops outputting current, the vehicle controller 70 performs a high-voltage interlock detection based on the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit 40. If the high-voltage circuit is detected to be intact, the entire vehicle is allowed to access the high voltage. When controlling the electric vehicle 10 to access the high voltage, the vehicle controller 70 controls the power supply switch 21 to close, thereby connecting the power battery 20 to multiple high-voltage assemblies. The power battery 20 outputs current to the bus capacitors of the multiple high-voltage assemblies to supply power to each high-voltage assembly, and at this time, the voltage of the bus capacitor of each high-voltage assembly increases.

[0091] During the high-voltage circuit continuity test, the bus capacitor of the high-voltage assembly is charged by the low-voltage battery 60 through the DC-DC converter circuit 40. The power supply switch 21 is not closed, and the voltage in the high-voltage circuit is low, resulting in a low risk of electric shock and high safety. After the high-voltage circuit continuity test is completed, the power supply switch 21 is closed only after the test results allow power-on. The bus capacitor of the high-voltage assembly is then directly powered by the power battery 20, and the voltage in the high-voltage circuit rises to the operating voltage. Although the voltage is high, the safety after power-on is ensured because the continuity of the high-voltage circuit has been verified.

[0092] In one embodiment, the vehicle controller 70 is specifically configured to control the DC-DC converter 40 to output current through its bus capacitor to charge the bus capacitor of each high-voltage assembly to a preset voltage before the power supply switch 21 is closed. Once the voltage of the bus capacitor of the DC-DC converter 40 reaches the preset voltage, the controller stops the DC-DC converter 40 from outputting current.

[0093] The vehicle controller 70 controls the DC-DC converter 40 to charge the bus capacitor of each high-voltage assembly to a preset voltage. To avoid the risk of electric shock, this preset voltage is less than or equal to a safe voltage, typically 60 V. During the process of controlling the DC-DC converter 40 to receive power from the low-voltage battery 60 and output current to multiple high-voltage assemblies through its bus capacitor, the voltage of both the DC-DC converter 40 bus capacitor and the high-voltage assembly bus capacitor gradually increases. The vehicle controller 70 monitors the voltage of either the DC-DC converter 40 bus capacitor or the high-voltage assembly bus capacitor in real time. The voltage of the bus capacitor of each high-voltage assembly can be obtained by detecting the voltage at the controller self-test port of each high-voltage assembly. When the voltage of the DC-DC converter 40 bus capacitor rises to the preset voltage, the DC-DC converter 40 stops reverse pre-charging and stops outputting current to the high-voltage circuit.

[0094] In one embodiment, the preset voltage is less than the voltage of the power battery 20.

[0095] The voltage of the power battery 20 is typically high, such as 400 V or 800 V. After the power supply switch 21 is closed, the voltage in the high-voltage circuit is as high as that of the power battery 20, increasing the risk of electric shock. Before the power supply switch 21 is closed, the vehicle controller 70 controls the DC-DC converter circuit 40 to charge the bus capacitor of each high-voltage assembly to a preset voltage. To avoid the risk of electric shock, this preset voltage is less than or equal to the safe voltage, which is typically 60 V.

[0096] For example, the preset voltage is 48 V.

[0097] Current high-voltage circuit disconnection detection technology for new energy vehicles is gradually evolving from low-voltage hard-wire interlock detection to software interlock detection schemes without separate low-voltage hard-wire interlock circuits, in order to reduce the false alarm rate and system cost of the entire vehicle. One high-voltage interlock detection scheme involves comparing the output voltage of the power battery 20 terminal with the port voltage of each high-voltage assembly after the electric vehicle 10 is powered on to perform high-voltage circuit continuity detection. However, since detection can only be performed after high-voltage power-on, it is impossible to perform detection before or during power-on. During high-voltage power-on, there is a possibility of high-voltage circuit disconnection, posing a safety risk of personnel coming into contact with high voltage. In contrast, the vehicle controller 70 of this application pre-charges the high-voltage circuit to a lower preset voltage in reverse through the DC-DC converter circuit 40 before high-voltage power-on, i.e. before the power supply switch 21 is closed, thereby enabling the continuous detection of the high-voltage circuit.

[0098] By utilizing the reverse pre-charge function of the DC-DC converter circuit 40, the voltage of the bus capacitor is pre-charged to below a safe voltage, for example, less than 60V, before high-voltage power is applied. After pre-charging, the connection status of each high-voltage assembly circuit is determined by judging the voltage difference between the voltage at each high-voltage assembly port and the voltage of the bus capacitor of the DC-DC converter circuit 40. The continuity of the high-voltage circuit is detected without adding low-voltage hard-wire interlocking lines, and the detection voltage is within the safe voltage range. This solves the problem that the current solution can only perform detection after high voltage is applied, and there is still a risk of electric shock during power-on, further improving system safety.

[0099] According to the solution of this application, the DC-DC converter circuit 40 precharges the high-voltage circuit to a preset voltage in reverse. Under the condition of a lower preset voltage, the connection status of each high-voltage assembly is determined by the voltage difference between the bus capacitor voltage of the high-voltage assembly and the voltage at the port of the DC-DC converter circuit 40. The high-voltage circuit continuity detection can be realized before the electric vehicle 10 is powered on, avoiding the risk of electric shock and improving the safety of the whole vehicle.

[0100] In one embodiment, the vehicle controller 70 is further configured to control the power supply switch 21 to remain open after the DC-DC converter circuit 40 stops outputting current, provided that the difference between the voltage of the bus capacitor of any one of the multiple high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit 40 is greater than or equal to a preset value.

[0101] After the DC-DC converter circuit 40 stops outputting current, the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit 40 are detected. If the difference between the voltage of the bus capacitor of any high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit 40 is greater than or equal to a preset value, that is, if the voltage of the bus capacitor of any high-voltage assembly is abnormally low, it indicates that there is a disconnection fault in the high-voltage circuit. The bus capacitor of any high-voltage assembly cannot normally receive the current output from the low-voltage battery 60. At this time, the vehicle is not allowed to apply high voltage. The vehicle controller 70 controls the power supply switch 21 to remain open and does not allow the power supply switch 21 to be closed.

[0102] In one embodiment, the vehicle controller 70 is further configured to control the power supply switch 21 to remain open and report a first fault information when the difference between the voltage of the bus capacitor of any one of the multiple high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit 40 is greater than or equal to a preset value. The first fault information is used to indicate that any one of the high-voltage assemblies has failed.

[0103] After the DC-DC converter circuit 40 stops outputting current, if the voltage difference between the bus capacitor of any high-voltage assembly and the bus capacitor of the DC-DC converter circuit 40 is greater than or equal to a preset value, it indicates that a certain high-voltage assembly has an open circuit fault. At this time, the entire vehicle is not allowed to receive high voltage. The vehicle controller 70 controls the power supply switch 21 to remain open, preventing the power supply switch 21 from closing. At the same time, it needs to report the first fault information, prompting the user that the electric vehicle 10 has a fault and needs repair. The first fault information is used to indicate that any high-voltage assembly with an open circuit fault where the voltage difference between the bus capacitor of the high-voltage assembly and the bus capacitor of the DC-DC converter circuit 40 is greater than or equal to a preset value has an open circuit fault. Since the voltage difference between the bus capacitor of this high-voltage assembly and the bus capacitor of the DC-DC converter circuit 40 is large, while the voltage difference between the bus capacitors of other high-voltage assemblies and the bus capacitors of the DC-DC converter circuit 40 is small, it indicates that this high-voltage assembly may have an open circuit fault and cannot normally receive the current output by the DC-DC converter circuit 40.

[0104] For example, based on Figure 3As shown, the vehicle controller 70 performs high-voltage circuit continuity detection based on the voltage of the bus capacitors of multiple high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit 40. When the voltage difference between the bus capacitor 1 of high-voltage assembly 1 and the bus capacitor of DC-DC converter circuit 40 is greater than a preset value, the voltage difference between the bus capacitor 2 of high-voltage assembly 2 and the bus capacitor of DC-DC converter circuit 40 is less than a preset value, and the voltage difference between the bus capacitor 3 of high-voltage assembly 3 and the bus capacitor of DC-DC converter circuit 40 is less than a preset value, the vehicle controller 70 controls the power supply switch 21 to remain open and reports a first fault information, which indicates that an open circuit fault has occurred in high-voltage assembly 1.

[0105] According to the solution in this application, the DC-DC converter circuit 40 is used for reverse pre-charging, and the low-voltage battery 60 is used to output current to the high-voltage circuit. The connection status of the high-voltage circuit is determined by the voltage difference, which high-voltage assembly has a disconnection fault. At the same time, the fault information is reported in a timely manner to remind the user to carry out maintenance while prohibiting the application of high voltage, so as to avoid the risk of electric shock, facilitate fault analysis and troubleshooting, and effectively improve the safety of the whole vehicle.

[0106] In one embodiment, the vehicle controller 70 is further configured to control the power supply switch 21 to remain open after the DC-DC converter circuit 40 stops outputting current, provided that the difference between the voltage of the bus capacitors of the plurality of high-voltage assemblies and the voltage of the bus capacitors of the DC-DC converter circuit 40 is greater than or equal to a preset value.

[0107] After the DC-DC converter circuit 40 stops outputting current, the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit 40 are detected. If the difference between the voltage of the bus capacitors of multiple high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit 40 is greater than or equal to a preset value, it indicates that there is a disconnection fault in the high-voltage circuit. The DC-DC converter circuit 40 may also have a disconnection fault. When the DC-DC converter circuit 40 has a disconnection fault, its bus capacitor can still receive current from the low-voltage battery 60 through the reverse pre-charge function, but it cannot output current to the high-voltage circuit. Therefore, the bus capacitors of the high-voltage assemblies cannot receive the current output by the DC-DC converter circuit 40. At this time, the vehicle is not allowed to be connected to high voltage. The vehicle controller 70 controls the power supply switch 21 to remain open and does not allow the power supply switch 21 to be closed.

[0108] In one embodiment, the vehicle controller 70 is further configured to control the power supply switch 21 to remain open and report a second fault information when the difference between the voltage of the bus capacitors of the plurality of high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit 40 is greater than or equal to a preset value. The second fault information is used to indicate that a fault has occurred in the DC-DC converter circuit 40.

[0109] After the DC-DC converter circuit 40 stops outputting current, if the voltage difference between the bus capacitors of multiple high-voltage assemblies and the bus capacitor of the DC-DC converter circuit 40 is greater than or equal to a preset value, it indicates that the DC-DC converter circuit 40 has an open circuit fault. At this time, the vehicle is not allowed to receive high voltage. The vehicle controller 70 controls the power supply switch 21 to remain open, preventing it from closing. Simultaneously, it reports a second fault message, alerting the user that the electric vehicle 10 has a fault requiring repair. The second fault message indicates that the DC-DC converter circuit 40 has an open circuit fault. Since the voltage difference between the bus capacitors of multiple high-voltage assemblies and the bus capacitor of the DC-DC converter circuit 40 is significant, and the probability of all high-voltage assemblies experiencing an open circuit fault simultaneously is very low, it is more likely that the DC-DC converter circuit 40 has an open circuit fault, causing the bus capacitors of other high-voltage assemblies to be unable to receive the current output from the DC-DC converter circuit 40.

[0110] For example, based on Figure 3 As shown, the vehicle controller 70 performs high-voltage circuit continuity detection based on the voltage of the bus capacitors of multiple high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit 40. When the voltage difference between the bus capacitor 1 of high-voltage assembly 1 and the bus capacitor of the DC-DC converter circuit 40 is greater than a preset value, the voltage difference between the bus capacitor 2 of high-voltage assembly 2 and the bus capacitor of the DC-DC converter circuit 40 is greater than a preset value, and the voltage difference between the bus capacitor 3 of high-voltage assembly 3 and the bus capacitor of the DC-DC converter circuit 40 is greater than a preset value, the vehicle controller 70 controls the power supply switch 21 to remain open and reports a second fault information, which indicates an open circuit fault in the DC-DC converter circuit 40.

[0111] In one embodiment, the vehicle controller 70 is further configured to control the power supply switch 21 to close when the voltage difference between the bus capacitor of the DC-DC converter 40 and the bus capacitor of each high-voltage assembly and the preset voltage is less than a preset value after the DC-DC converter 40 stops outputting current.

[0112] After the DC-DC converter circuit 40 stops outputting current, the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit 40 are detected. When the difference between the voltage of the bus capacitor of the DC-DC converter circuit 40 and the bus capacitor of each high-voltage assembly and the preset voltage is less than the preset value, that is, the voltage of the bus capacitor of the DC-DC converter circuit 40 and the bus capacitor of each high-voltage assembly has basically reached the preset voltage, it indicates that the high-voltage circuit is complete and the bus capacitor of each high-voltage assembly is receiving the current output from the low-voltage battery 60 normally. At this time, the vehicle is allowed to operate at high voltage. The vehicle controller 70 controls the power supply switch 21 to close, connecting the power battery 20 and multiple high-voltage assemblies.

[0113] In one embodiment, the vehicle controller 70 is further configured to control the power supply switch 21 to remain open after the DC-DC converter 40 stops outputting current, when the difference between the voltage of the bus capacitor of the DC-DC converter 40 or the bus capacitor of any one of the multiple high-voltage assemblies and a preset voltage is greater than or equal to a preset value.

[0114] After the DC-DC converter circuit 40 stops outputting current, the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit 40 are detected. If the difference between the voltage of the bus capacitor of the DC-DC converter circuit 40 or the bus capacitor of any one of the high-voltage assemblies and the preset voltage is greater than or equal to the preset value, it indicates that there is a disconnection fault in the high-voltage circuit. If the bus capacitor of the DC-DC converter circuit 40 or any one of the high-voltage assemblies has a disconnection fault and the voltage does not reach the preset voltage, the entire vehicle is not allowed to be connected to high voltage. The vehicle controller 70 controls the power supply switch 21 to remain open and does not allow the power supply switch 21 to be closed.

[0115] Figure 4 This is a schematic diagram of a control method provided in an embodiment of this application.

[0116] This control method is used to detect the connection status of the power battery 20 of the electric vehicle 10 with multiple high-voltage assemblies. This control method is applied to the architecture of the electric vehicle 10 described above.

[0117] The control method includes, before the power supply switch 21 is closed, controlling the DC-DC converter 40 to receive power from the low-voltage battery 60 and outputting current through the bus capacitor of the DC-DC converter 40 to charge the bus capacitor of each high-voltage assembly to a preset voltage. When the voltage of the bus capacitor of the DC-DC converter 40 reaches the preset voltage, controlling the DC-DC converter 40 to stop outputting current. After the DC-DC converter 40 stops outputting current, when the difference between the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter 40 is less than a preset value, controlling the power supply switch 21 to close.

[0118] like Figure 4 As shown, when the electric vehicle 10 detects that the user intends to apply high voltage, it sends a detection request to each high-voltage assembly to perform a high-voltage circuit continuity test. The DC-DC converter circuit 40 is controlled to activate the reverse pre-charge function to pre-charge each high-voltage assembly. Reverse pre-charging stops when the voltage of the bus capacitor of each high-voltage assembly or the bus capacitor of the DC-DC converter circuit 40 reaches a preset voltage. Each high-voltage assembly reports the voltage of its self-test port, and the voltage of each high-voltage assembly is compared with the voltage of the DC-DC converter circuit 40.

[0119] When the voltage difference between the bus capacitor of each high-voltage assembly and the bus capacitor of the DC-DC converter circuit 40 is less than the preset value, high voltage is applied and the control power supply switch 21 is closed.

[0120] In one embodiment, the control method further includes, after the DC-DC converter 40 stops outputting current, if the difference between the voltage of the bus capacitor of any one of the plurality of high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter 40 is greater than or equal to a preset value, controlling the power supply switch 21 to remain open and reporting a first fault information, the first fault information being used to indicate that any one of the high-voltage assemblies has failed. Alternatively, if the difference between the voltage of the bus capacitor of the plurality of high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter 40 is greater than or equal to a preset value, controlling the power supply switch 21 to remain open and reporting a second fault information, the second fault information being used to indicate that the DC-DC converter 40 has failed.

[0121] Figure 5 This is a schematic diagram of another vehicle controller 70 provided in an embodiment of this application.

[0122] The vehicle controller 70 can be a vehicle controller, a battery management system (BMS) controller, an on-board charger 50 controller, or a controller for other high-voltage assemblies, or it can be any other controller with processing capabilities.

[0123] like Figure 5 As shown, the electric vehicle 10 includes a power battery 20, an on-board charger 50, and multiple high-voltage assemblies. The power battery 20 supplies power to the bus capacitor of each high-voltage assembly through a power supply switch 21. The on-board charger 50 receives AC power and charges the power battery 20 through the power supply switch 21.

[0124] The vehicle controller 70 controls the on-board charger 50 to receive AC power and output current to multiple high-voltage assemblies through its output port before the on-board charger 50 charges the power battery 20 and the power supply switch 21 is closed. After the on-board charger 50 stops outputting current, when the difference between the voltage of the bus capacitor of each high-voltage assembly and the voltage of the output port is less than a preset value, the controller controls the power supply switch 21 to close so that the on-board charger 50 charges the power battery 20.

[0125] Multiple high-voltage assemblies of the electric vehicle 10 are connected to the power battery 20 via a power supply switch 21. The power supply switch 21 is used to control whether the electric vehicle 10 is powered on at high voltage.

[0126] The on-board charger 50 is used to charge the power battery 20 of the electric vehicle 10. The on-board charger 50 is connected to an AC power source and connected to the power battery 20 via a power switch 21. The on-board charger 50 receives AC power from the AC power source and converts it to DC power, charging the power battery 20 through its output port. The on-board charger 50 includes a power factor correction circuit and a resonant converter circuit. The power factor correction circuit adjusts the power factor of the input AC power to ensure efficient energy transfer between the AC power source and the power battery 20. The resonant converter circuit converts the DC power output from the power factor correction circuit and charges the power battery 20. The resonant converter circuit includes a primary-side rectifier circuit, a resonant cavity, and a secondary-side rectifier circuit. The primary-side rectifier circuit receives the DC power output from the power factor correction circuit, rectifies it, and inputs it into the resonant cavity. The secondary-side rectifier circuit receives the current output from the resonant cavity, rectifies it, and inputs the current into the high-voltage DC bus through its output port.

[0127] When the electric vehicle 10 is charging the power battery 20, the power supply switch 21 is closed, and the connection between the power battery 20 and the high-voltage assembly is established. Therefore, it is also necessary to perform continuity testing on the high-voltage circuit. The electric vehicle 10 detects the connection status of high-voltage components, connectors, and wiring to ensure that the high-voltage system is energized only when all components are reliably connected and there is no risk of personnel contact. If any abnormality is detected, such as a disconnected connector or damaged wiring, the high-voltage power supply is immediately cut off to avoid electric shock accidents.

[0128] Before the on-board charger 50 charges the power battery 20 and the power supply switch 21 is closed, that is, after the on-board charger 50 is connected to the DC power supply, the electric vehicle 10 is about to start charging the power battery 20. Before the power supply switch 21 is closed, the high-voltage circuit continuity is detected. The vehicle controller 70 controls the on-board charger 50 to receive the power supply from the AC power supply and output current to multiple high-voltage assemblies through the output port. Thus, the on-board charger 50 converts the AC power output from the AC power supply into DC power and charges the bus capacitors of multiple high-voltage assemblies in the high-voltage circuit.

[0129] After the on-board charger 50 stops outputting current, if the difference between the voltage of the bus capacitor of each high-voltage assembly and the voltage at the output port is less than a preset value, it indicates that the high-voltage circuit is complete and the bus capacitor of each high-voltage assembly is normally receiving the current output by the on-board charger 50. At this time, the entire vehicle is allowed to operate at high voltage. The control power supply switch 21 is closed to allow the on-board charger 50 to charge the power battery 20.

[0130] It should be understood that, since an AC power supply is required to pre-charge the high-voltage circuit, the vehicle controller 70 can only perform the above control in the scenario where the electric vehicle 10 is AC charging.

[0131] According to the solution of this application, the AC power output from the AC power supply is converted into DC power by the on-board charger 50 and output current to the high-voltage circuit. When the voltage difference between the bus capacitor voltage of the high-voltage assembly and the output port of the on-board charger 50 is less than a preset value, the power supply switch 21 is controlled to be turned on. The connection status of the high-voltage circuit is determined by the voltage difference. There is no need to add an additional low-voltage wiring harness, which reduces costs and simplifies the hardware structure. Furthermore, the continuity detection of the high-voltage circuit is realized before the electric vehicle 10 is powered on, avoiding the risk of electric shock and improving the safety of the whole vehicle.

[0132] In one embodiment, the vehicle controller 70 is specifically configured to receive AC power from the on-board charger 50 before the power supply switch 21 is closed, and output current through the output port to charge the bus capacitor of each high-voltage assembly to a preset voltage. When the voltage at the output port reaches the preset voltage, the on-board charger 50 is controlled to stop outputting current.

[0133] The vehicle controller 70 controls the on-board charger 50 to charge the bus capacitor of each high-voltage assembly to a preset voltage. To avoid the risk of electric shock, this preset voltage is less than or equal to a safe voltage, typically 60V. During the process of controlling the on-board charger 50 to receive AC power and output current to multiple high-voltage assemblies through its output port, the voltage of the bus capacitor of the high-voltage assembly gradually rises. The vehicle controller 70 monitors the voltage at the output port of the on-board charger 50 or the voltage of the bus capacitor of the high-voltage assembly in real time. The voltage of the bus capacitor of each high-voltage assembly can be obtained by detecting the voltage at the controller self-test port of each high-voltage assembly. When the voltage at the output port of the on-board charger 50 rises to the preset voltage, the on-board charger 50 stops pre-charging and stops outputting current to the high-voltage circuit.

[0134] In one embodiment, the preset voltage is less than the voltage of the power battery 20.

[0135] The voltage of the power battery 20 is typically high, such as 400 V or 800 V. After the power supply switch 21 is closed, the voltage in the high-voltage circuit is as high as that of the power battery 20, increasing the risk of electric shock. Before the power supply switch 21 is closed, the vehicle controller 70 controls the on-board charger 50 to charge the bus capacitor of each high-voltage assembly to a preset voltage. To avoid the risk of electric shock, this preset voltage is less than or equal to the safe voltage, which is typically 60 V.

[0136] For example, the preset voltage is 48 V.

[0137] In one embodiment, the vehicle controller 70 is further configured to control the power supply switch 21 to remain open after the on-board charger 50 stops outputting current, provided that the difference between the voltage of the bus capacitor of any one of the multiple high-voltage assemblies and the voltage of the output port is greater than or equal to a preset value.

[0138] After the on-board charger 50 stops outputting current, the voltage of the bus capacitor of each high-voltage assembly and the voltage of the output port of the on-board charger 50 are detected. If the difference between the voltage of the bus capacitor of any high-voltage assembly and the voltage of the output port is greater than or equal to a preset value, that is, if the voltage of the bus capacitor of any high-voltage assembly is abnormally low, it indicates that there is a disconnection fault in the high-voltage circuit. The bus capacitor of any high-voltage assembly cannot normally receive the current output by the on-board charger 50, and the entire vehicle is not allowed to be connected to high voltage. The vehicle controller 70 controls the power supply switch 21 to remain open and does not allow the power supply switch 21 to be closed.

[0139] In one embodiment, the vehicle controller 70 is further configured to control the power supply switch 21 to remain open and report a third fault information when the difference between the voltage of the bus capacitor of any one of the multiple high-voltage assemblies and the voltage of the output port is greater than or equal to a preset value. The third fault information is used to indicate that any one of the high-voltage assemblies has failed.

[0140] After the on-board charger 50 stops outputting current, if the difference between the voltage of the bus capacitor of any high-voltage assembly and the voltage at the output port of the on-board charger 50 is greater than or equal to a preset value, it indicates that a certain high-voltage assembly has an open circuit fault. At this time, the entire vehicle is not allowed to receive high voltage. The vehicle controller 70 controls the power supply switch 21 to remain open, preventing it from closing. Simultaneously, it needs to report a third fault message, alerting the user that the electric vehicle 10 has a fault requiring repair. The third fault message indicates that any high-voltage assembly with a bus capacitor voltage difference greater than or equal to a preset value has an open circuit fault. Because the voltage difference between the bus capacitor voltage of this high-voltage assembly and the output port of the on-board charger 50 is large, while the voltage difference between the bus capacitor voltage of other high-voltage assemblies and the output port of the on-board charger 50 is small, it indicates that this high-voltage assembly may have an open circuit fault and cannot normally receive the current output from the on-board charger 50.

[0141] For example, based on Figure 5As shown, the vehicle controller 70 performs high-voltage circuit continuity detection based on the voltage of the bus capacitors of multiple high-voltage assemblies and the voltage of the output port of the on-board charger 50. When the voltage difference between the bus capacitor 1 of high-voltage assembly 1 and the output port of the on-board charger 50 is greater than a preset value, the voltage difference between the bus capacitor 2 of high-voltage assembly 2 and the output port of the on-board charger 50 is less than a preset value, and the voltage difference between the bus capacitor 3 of high-voltage assembly 3 and the output port of the on-board charger 50 is less than a preset value, the vehicle controller 70 controls the power supply switch 21 to remain open and reports a third fault information, which indicates that an open circuit fault has occurred in high-voltage assembly 1.

[0142] In one embodiment, the vehicle controller 70 is further configured to control the power supply switch 21 to remain open after the on-board charger 50 stops outputting current, provided that the difference between the voltage of the bus capacitors of the multiple high-voltage assemblies and the voltage of the output port is greater than or equal to a preset value.

[0143] After the on-board charger 50 stops outputting current, the voltage of the bus capacitor of each high-voltage assembly and the voltage of the output port of the on-board charger 50 are detected. If the difference between the voltage of the bus capacitor of multiple high-voltage assemblies and the voltage of the output port of the on-board charger 50 is greater than or equal to a preset value, it indicates that there is a disconnection fault in the high-voltage circuit. The on-board charger 50 may also have a disconnection fault. When the on-board charger 50 has a disconnection fault, its output port can still convert AC power to DC power, but it cannot input into the high-voltage circuit, so the bus capacitor of the high-voltage assembly cannot receive current. At this time, high voltage is not allowed to be applied to the entire vehicle. The vehicle controller 70 controls the power supply switch 21 to remain open and does not allow the power supply switch 21 to be closed.

[0144] In one embodiment, the vehicle controller 70 is further configured to control the power supply switch 21 to remain open and report a fourth fault information when the difference between the voltage of the bus capacitors of the plurality of high-voltage assemblies and the voltage of the output port is greater than or equal to a preset value. The fourth fault information is used to indicate that the on-board charger 50 has malfunctioned.

[0145] After the on-board charger 50 stops outputting current, if the voltage difference between the bus capacitors of multiple high-voltage assemblies and the voltage at the output port of the on-board charger 50 is greater than or equal to a preset value, it indicates that the on-board charger 50 has a disconnection fault. At this time, high voltage is not allowed on the entire vehicle. The vehicle controller 70 controls the power supply switch 21 to remain open, preventing it from closing. Simultaneously, it reports a fourth fault message, alerting the user that the electric vehicle 10 has a fault requiring repair. The fourth fault message indicates an open-circuit fault in the on-board charger 50. Since the voltage difference between the bus capacitors of multiple high-voltage assemblies and the voltage at the output port of the on-board charger 50 is significant, and the probability of all high-voltage assemblies experiencing an open-circuit fault simultaneously is very low, it is more likely that the on-board charger 50 has an open-circuit fault, causing the bus capacitors of other high-voltage assemblies to be unable to receive the current output from the on-board charger 50.

[0146] For example, based on Figure 5 As shown, the vehicle controller 70 performs high-voltage circuit continuity detection based on the voltage of the bus capacitors of multiple high-voltage assemblies and the voltage of the output port of the on-board charger 50. When the voltage difference between the bus capacitor 1 of high-voltage assembly 1 and the output port of the on-board charger 50 is greater than a preset value, the voltage difference between the bus capacitor 2 of high-voltage assembly 2 and the output port of the on-board charger 50 is greater than a preset value, and the voltage difference between the bus capacitor 3 of high-voltage assembly 3 and the output port of the on-board charger 50 is greater than a preset value, the vehicle controller 70 controls the power supply switch 21 to remain open and reports a fourth fault information, which indicates that an open circuit fault has occurred in the on-board charger 50.

[0147] In one embodiment, the vehicle controller 70 is further configured to control the power supply switch 21 to close when the difference between the voltage of the output port and the bus capacitor of each high voltage assembly and the preset voltage is less than the preset value after the on-board charger 50 stops outputting current.

[0148] After the on-board charger 50 stops outputting current, the voltage of the bus capacitor of each high-voltage assembly and the voltage of the output port of the on-board charger 50 are detected. When the difference between the output port of the on-board charger 50 and the voltage of the bus capacitor of each high-voltage assembly and the preset voltage is less than the preset value, that is, when the output port of the on-board charger 50 and the voltage of the bus capacitor of each high-voltage assembly have basically reached the preset voltage, it indicates that the high-voltage circuit is complete and the bus capacitor of each high-voltage assembly is receiving the current output by the on-board charger 50 normally. At this time, the entire vehicle is allowed to operate at high voltage. The vehicle controller 70 controls the power supply switch 21 to close, connecting the power battery 20 and multiple high-voltage assemblies.

[0149] In one embodiment, the vehicle controller 70 is further configured to control the power supply switch 21 to remain open after the on-board charger 50 stops outputting current, when the difference between the voltage of the bus capacitor of the output port or any one of the multiple high-voltage assemblies and the preset voltage is greater than or equal to a preset value.

[0150] After the on-board charger 50 stops outputting current, the voltage of the bus capacitor of each high-voltage assembly and the voltage of the output port of the on-board charger 50 are detected. If the difference between the voltage of the output port of the on-board charger 50 or the bus capacitor of any of the multiple high-voltage assemblies and the preset voltage is greater than or equal to the preset value, it indicates that there is a disconnection fault in the high-voltage circuit. If the on-board charger 50 or any of the high-voltage assemblies has a disconnection fault and the voltage does not reach the preset voltage, the entire vehicle is not allowed to be connected to high voltage. The vehicle controller 70 controls the power supply switch 21 to remain open and does not allow the power supply switch 21 to be closed.

[0151] Figure 6 This is a schematic diagram of another control method provided in the embodiments of this application.

[0152] This control method is used to detect the connection status of the power battery 20 of the electric vehicle 10 with multiple high-voltage assemblies before AC charging of the power battery 20. This control method is applied to the architecture of the electric vehicle 10 described above.

[0153] The control method includes controlling the on-board charger 50 to receive AC power and output current through its output port to charge the bus capacitor of each high-voltage assembly to a preset voltage before the on-board charger 50 charges the power battery 20 and the power supply switch 21 is closed. Once the voltage at the output port reaches the preset voltage, the on-board charger 50 stops outputting current. After the on-board charger 50 stops outputting current, when the difference between the voltage of the bus capacitor of each high-voltage assembly and the voltage at the output port is less than a preset value, the power supply switch 21 is closed to allow the on-board charger 50 to charge the power battery 20.

[0154] like Figure 6 As shown, when the electric vehicle 10 detects AC charging, it sends a test request to each high-voltage assembly to perform high-voltage circuit continuity testing. Before the power supply switch 21 is closed, the on-board charger 50 is controlled to pre-charge each high-voltage assembly. Pre-charging stops when the bus capacitor of each high-voltage assembly or the voltage at the output port of the on-board charger 50 reaches a preset voltage. Each high-voltage assembly reports the voltage at its self-test port, and the voltage of each high-voltage assembly is compared with the voltage at the output port of the on-board charger 50.

[0155] When the difference between the voltage of the bus capacitor of each high-voltage assembly and the voltage of the output port is less than the preset value, the power supply switch 21 is closed to allow the on-board charger 50 to charge the power battery 20.

[0156] In one embodiment, the control method further includes controlling the power supply switch 21 to remain open and reporting a third fault information when the difference between the voltage of the bus capacitor of any one of the multiple high-voltage assemblies and the voltage of the output port is greater than or equal to a preset value. The third fault information is used to indicate that any one of the high-voltage assemblies has failed. Alternatively, when the difference between the voltage of the bus capacitor of all multiple high-voltage assemblies and the voltage of the output port is greater than or equal to a preset value, controlling the power supply switch 21 to remain open and reporting a fourth fault information, the fourth fault information is used to indicate that the on-board charger 50 has failed.

[0157] It should be understood that the two methods of pre-charging the high-voltage circuit via DC-DC converter 40 and charging the high-voltage circuit via on-board charger 50 before the electric vehicle 10 is connected to high voltage can be implemented individually or in combination. For example, when the electric vehicle 10 is not connected to an AC power source, and the electric vehicle 10 needs to be connected to high voltage, the high-voltage circuit continuity test is performed by pre-charging the high-voltage circuit via DC-DC converter 40; when the electric vehicle 10 is connected to an AC power source, and the electric vehicle 10 needs to be connected to high voltage, the high-voltage circuit continuity test is performed by charging the high-voltage circuit via on-board charger 50.

[0158] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A vehicle controller for electric vehicles, characterized in that, The electric vehicle includes a power battery, a DC-DC converter circuit, and multiple high-voltage assemblies. The power battery supplies power to the bus capacitor of each high-voltage assembly via a power switch. The DC-DC converter circuit steps down the DC power output from the power battery to provide low-voltage battery power. The vehicle controller is used for: Before the power supply switch is closed, the DC-DC converter circuit is controlled to receive power from the low-voltage battery and output current to the multiple high-voltage assemblies through the bus capacitor of the DC-DC converter circuit; After the DC-DC converter circuit stops outputting current, when the difference between the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit is less than a preset value, the power supply switch is controlled to close.

2. The vehicle controller according to claim 1, characterized in that, The vehicle controller is specifically used for: Before the power supply switch is closed, the DC-DC converter is controlled to output current through the bus capacitor of the DC-DC converter to charge the bus capacitor of each high voltage assembly to a preset voltage; When the voltage of the bus capacitor of the DC-DC converter circuit reaches the preset voltage, the DC-DC converter circuit is controlled to stop outputting current.

3. The vehicle controller according to claim 1 or 2, characterized in that, The vehicle controller is also used for: After the DC-DC converter circuit stops outputting current, if the difference between the voltage of the bus capacitor of any one of the multiple high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit is greater than or equal to the preset value, the power supply switch is controlled to remain open.

4. The vehicle controller according to any one of claims 1-3, characterized in that, The vehicle controller is also used for: After the DC-DC converter circuit stops outputting current, when the difference between the voltage of the bus capacitor of the plurality of high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit is greater than or equal to the preset value, the power supply switch is controlled to remain open.

5. The vehicle controller according to claim 2, characterized in that, The vehicle controller is also used for: After the DC-DC converter circuit stops outputting current, when the difference between the voltage of the bus capacitor of the DC-DC converter circuit and the bus capacitor of each high-voltage assembly and the preset voltage is less than the preset value, the power supply switch is controlled to close.

6. The vehicle controller according to claim 2, characterized in that, The vehicle controller is also used for: After the DC-DC converter circuit stops outputting current, when the difference between the voltage of the bus capacitor of the DC-DC converter circuit or the bus capacitor of any one of the plurality of high-voltage assemblies and the preset voltage is greater than or equal to the preset value, the power supply switch is controlled to remain open.

7. The vehicle controller according to any one of claims 1-6, characterized in that, The vehicle controller is specifically used for: By controlling the power supply switch to close, the power battery outputs current to the bus capacitors of the plurality of high-voltage assemblies to increase the voltage of the bus capacitors of each high-voltage assembly.

8. The vehicle controller according to claim 3, characterized in that, The vehicle controller is also used for: When the difference between the voltage of the bus capacitor of any one of the plurality of high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit is greater than or equal to the preset value, the power supply switch is controlled to remain open and a first fault information is reported. The first fault information is used to indicate that any one of the high-voltage assemblies has failed.

9. The vehicle controller according to claim 4, characterized in that, The vehicle controller is also used for: When the difference between the voltage of the bus capacitor of the plurality of high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit is greater than or equal to the preset value, the power supply switch is controlled to remain open and a second fault information is reported. The second fault information is used to indicate that a fault has occurred in the DC-DC converter circuit.

10. The vehicle controller according to any one of claims 2-9, characterized in that, The preset voltage is less than the voltage output by the power battery.

11. The vehicle controller according to any one of claims 1-10, characterized in that, The vehicle controller is specifically used for: When the electric vehicle start command is received, the start command is used to instruct the power battery to supply power to the multiple high-voltage assemblies. Before the power supply switch is closed, the DC-DC converter is controlled to receive the power supply from the low-voltage battery and output current to the multiple high-voltage assemblies through the bus capacitor of the DC-DC converter.

12. A control method for electric vehicles, characterized in that, The control method is used to detect the connection status between the power battery of the electric vehicle and multiple high-voltage assemblies. The power battery supplies power to the bus capacitor of each high-voltage assembly through a power supply switch. The electric vehicle includes a DC-DC converter circuit, which is used to step down the DC power output from the power battery to supply power to the battery at a low voltage. The control method includes: Before the power supply switch is closed, the DC-DC converter circuit is controlled to receive power from the low-voltage battery and output current through the bus capacitor of the DC-DC converter circuit to charge the bus capacitor of each high-voltage assembly to a preset voltage; When the voltage of the bus capacitor of the DC-DC converter circuit reaches the preset voltage, the DC-DC converter circuit is controlled to stop outputting current. After the DC-DC converter circuit stops outputting current, when the difference between the voltage of the bus capacitor of each high-voltage assembly and the voltage of the bus capacitor of the DC-DC converter circuit is less than a preset value, the power supply switch is controlled to close.

13. The control method according to claim 12, characterized in that, The control method further includes: After the DC-DC converter circuit stops outputting current, if the voltage difference between the bus capacitor of any one of the plurality of high-voltage assemblies and the bus capacitor of the DC-DC converter circuit is greater than or equal to the preset value, the power supply switch is controlled to remain open and a first fault information is reported. The first fault information is used to indicate that any one of the high-voltage assemblies has failed; or, When the difference between the voltage of the bus capacitor of the plurality of high-voltage assemblies and the voltage of the bus capacitor of the DC-DC converter circuit is greater than or equal to the preset value, the power supply switch is controlled to remain open and a second fault information is reported. The second fault information is used to indicate that a fault has occurred in the DC-DC converter circuit.

14. An electric vehicle, characterized in that, The electric vehicle includes a power battery, multiple high-voltage assemblies, and a vehicle controller as described in any one of claims 1-11, wherein the multiple high-voltage assemblies include a powertrain for receiving power from the power battery to drive the electric vehicle.

Images