CN-122008908-A - Vehicle controller, control method and electric vehicle

CN122008908ACN 122008908 ACN122008908 ACN 122008908ACN-122008908-A

Abstract

A vehicle controller, a control method and an electric vehicle relate 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, wherein the power battery is used for supplying power to a bus capacitor of each high-voltage assembly through a power supply switch, the direct current conversion circuit is used for performing buck conversion on direct current output by the power battery to supply power to a low-voltage battery, and the vehicle controller is used for controlling the direct current conversion circuit to receive the power supply of the low-voltage battery and output current to the plurality of high-voltage assemblies through the bus capacitor of the direct current conversion circuit before the power supply switch is closed. After the direct current conversion circuit stops outputting 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 closed. According to the scheme, the continuity detection of the high-voltage loop can be realized before the high-voltage power on of the electric vehicle, so that the electric shock risk is avoided, and the safety of the whole vehicle is improved.

Inventors

LIU YANBO
LIU XIAOLONG
ZHAO FUGAO
CHEN TAIXIAN
ZHENG YOUXIANG
LIANG TAO
ZHANG ZHUORAN
ZHAO PENGHUI

Assignees

华为技术有限公司

Dates

Publication Date: 20260512
Application Date: 20260126

Claims (14)

1. A vehicle controller for an electric vehicle, the electric vehicle comprising a power battery for supplying power to a bus capacitor of each high voltage assembly through a power supply switch, a dc conversion circuit for down-converting dc power output from the power battery to low voltage battery power, and a plurality of high voltage assemblies, the vehicle controller being configured to: Before the power supply switch is closed, controlling the direct current conversion circuit to receive power supply of the low-voltage battery and outputting current to the plurality of high-voltage assemblies through a bus capacitor of the direct current conversion circuit; after the direct current conversion circuit stops outputting 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 closed.
2. The vehicle controller of claim 1, characterized in that the vehicle controller is specifically configured to: before the power supply switch is closed, controlling the direct current conversion circuit to charge the bus capacitor of each high-voltage assembly to a preset voltage through the bus capacitor output current of the direct current conversion circuit; And after the voltage of the bus capacitor of the direct current conversion circuit reaches the preset voltage, controlling the direct current conversion circuit to stop outputting current.
3. The vehicle controller according to claim 1 or 2, characterized in that the vehicle controller is further configured to: After the direct current conversion circuit stops outputting current, when the difference value 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 direct current conversion circuit is larger than or equal to the preset value, the power supply switch is controlled to be kept off.
4. A vehicle controller according to any one of claims 1-3, characterized in that the vehicle controller is further adapted to: After the direct current conversion circuit stops outputting current, when the difference value between the voltages of the bus capacitors of the high voltage assemblies and the voltage of the bus capacitors of the direct current conversion circuit is larger than or equal to the preset value, the power supply switch is controlled to be kept off.
5. The vehicle controller of claim 2, further characterized in that the vehicle controller is configured to: After the direct current conversion circuit stops outputting current, when the difference value between the voltage of the bus capacitor of the direct current conversion circuit and the bus capacitor of each high-voltage assembly and the preset voltage is smaller than a preset value, the power supply switch is controlled to be closed.
6. The vehicle controller of claim 2, further characterized in that the vehicle controller is configured to: After the direct current conversion circuit stops outputting current, when the difference value between the voltage of the bus capacitor of the direct current conversion circuit or the bus capacitor of any one of the plurality of high-voltage assemblies and the preset voltage is larger than or equal to the preset value, the power supply switch is controlled to be kept off.
7. The vehicle controller according to any one of claims 1-6, characterized in that the vehicle controller is specifically configured to: and controlling the power supply switch to be closed, and outputting current to the bus capacitors of the high-voltage assemblies by the power battery so as to increase the voltage of the bus capacitor of each high-voltage assembly.
8. The vehicle controller of claim 3, further characterized in that the vehicle controller is configured to: When the difference value 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 direct-current conversion circuit is larger than or equal to the preset value, the power supply switch is controlled to be kept off and first fault information is reported, and the first fault information is used for indicating that any one of the high-voltage assemblies fails.
9. The vehicle controller of claim 4, further characterized in that the vehicle controller is configured to: When the difference value between the voltage of the bus capacitors of the high-voltage assemblies and the voltage of the bus capacitors of the direct-current conversion circuit is larger than or equal to the preset value, the power supply switch is controlled to be kept off, and second fault information is reported, wherein the second fault information is used for indicating that the direct-current conversion circuit breaks down.
10. The vehicle controller according to any one of claims 2 to 9, characterized in that the preset voltage is smaller than the voltage output from the power battery.
11. The vehicle controller according to any one of claims 1-10, characterized in that the vehicle controller is specifically configured to: When the starting instruction of the electric vehicle is received, the starting instruction is used for indicating the power battery to supply power to the plurality of high-voltage assemblies, and before the power supply switch is closed, the direct-current conversion circuit is controlled to receive the power supply of the low-voltage battery and output current to the plurality of high-voltage assemblies through the bus capacitor of the direct-current conversion circuit.
12. A control method for an electric vehicle, the control method being for detecting a connection state of a power battery of the electric vehicle with a plurality of high voltage assemblies, the power battery being for supplying power to a bus capacitor of each of the high voltage assemblies through a power supply switch, the electric vehicle including a dc conversion circuit for down-converting a dc power output from the power battery into a battery power, the control method comprising: before the power supply switch is closed, controlling the direct current conversion circuit to receive power supply of the low-voltage battery and charging the bus capacitor of each high-voltage assembly to a preset voltage through bus capacitor output current of the direct current conversion circuit; When the voltage of the bus capacitor of the direct current conversion circuit reaches the preset voltage, controlling the direct current conversion circuit to stop outputting current; after the direct current conversion circuit stops outputting 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 closed.
13. The control method according to claim 12, characterized in that the control method further comprises: After the DC conversion circuit stops outputting current, when the difference value 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 conversion circuit is larger than or equal to the preset value, the power supply switch is controlled to be kept off and first fault information is reported, wherein the first fault information is used for indicating that any one of the high-voltage assemblies fails, or When the difference value between the voltage of the bus capacitors of the high-voltage assemblies and the voltage of the bus capacitors of the direct-current conversion circuit is larger than or equal to the preset value, the power supply switch is controlled to be kept off, and second fault information is reported, wherein the second fault information is used for indicating that the direct-current conversion circuit breaks down.
14. An electric vehicle comprising a power battery, a plurality of high voltage assemblies including a power assembly for receiving power from the power battery to drive the electric vehicle, and a vehicle controller as claimed in any one of claims 1 to 11.

Description

Vehicle controller, control method and electric vehicle Technical Field The present application relates to the field of electric vehicles, and more particularly, to a vehicle controller, a control method, and an electric vehicle. Background With the popularization of electric vehicles, safety problems of electric vehicles are becoming more and more important. The electric vehicle outputs current through the high-voltage power battery to supply power for the driving motor and other high-voltage loads, and in the use process, the condition that a high-voltage loop is exposed possibly occurs, so that the risk of accidental electric shock is increased. High voltage interlock (high voltage interlock loop, HVIL) detection is therefore required. The high-voltage interlocking is a core safety protection mechanism of a high-voltage system of a new energy automobile. The live part of the high-voltage loop is exposed and electrically interlocked with the high-voltage system, namely the live part is exposed, the system needs to be powered down, and when the system is powered up, the loop cannot be exposed. The electric vehicle detects the connection state of high-voltage components, connectors and circuits, ensures that a high-voltage system is electrified only when all the components are reliably connected and no contact risk of personnel exists, and immediately cuts off a high-voltage power supply once abnormality such as disconnection of the connectors, breakage of the circuits and the like is detected, so as to avoid electric shock accidents. The existing high-voltage interlocking detection mainly detects the integrity of a high-voltage loop through a low-voltage signal, an additional low-voltage line is required to be added for signal transmission, the complexity of the system is high, and the high-voltage interlocking detection cost is high. Therefore, how to effectively detect the continuity of the high-voltage circuit is a problem to be solved. Disclosure of Invention The application provides a vehicle controller, a control method and an electric vehicle, wherein before a high-voltage system is electrified, a direct-current conversion circuit is used for pre-charging voltage of a high-voltage loop, the connection state of each high-voltage assembly is judged according to the voltage difference value between the bus capacitor voltage of each high-voltage assembly and the bus capacitor of the direct-current conversion circuit, and before the electric vehicle is electrified at high voltage, the continuity detection of the high-voltage loop can be realized, the electric shock risk is avoided, and the safety of the whole vehicle is improved. In a first aspect, the present application provides a vehicle controller for an electric vehicle, the electric vehicle including a power battery, a dc conversion circuit, and a plurality of high voltage assemblies, the power battery being configured to supply power to a bus capacitor of each high voltage assembly through a power switch, the dc conversion circuit being configured to buck-convert dc power output from the power battery to power the battery, the vehicle controller being configured to control the dc conversion circuit to receive power from the low voltage battery and output current to the plurality of high voltage assemblies through the bus capacitor of the dc conversion circuit before the power switch is closed. After the direct current conversion circuit stops outputting 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 closed. The direct current conversion circuit is used for being connected with the power battery and the low-voltage battery. The direct current conversion circuit is used for converting high-voltage direct current output by the power battery into low-voltage direct current in a down-converting mode to charge the power battery. The direct current conversion circuit also has a reverse pre-charging function, and is used for receiving the power supply of the low-voltage battery and outputting current to the high-voltage bus so as to charge the bus capacitors of the high-voltage assemblies. The low-voltage battery has one or more batteries. The voltage of the low-voltage battery is lower than the voltage output by the power battery. The bus capacitor of the direct current conversion circuit is used for connecting a high-voltage direct current bus, and the bus capacitor is used for receiving current from a low-voltage battery and charging the low-voltage battery so as to output current to the high-voltage assembly through the high-voltage direct current bus. The high voltage assembly of the application refers to an electric component connected with and receiving power supplied by a power battery, and comprises, but is not limited to, a power assemb