CN-121989687-A - Low-voltage storage battery electricity supplementing system of pure electric vehicle and control method thereof

CN121989687ACN 121989687 ACN121989687 ACN 121989687ACN-121989687-A

Abstract

A low-voltage storage battery power supply system of a pure electric vehicle and a control method thereof comprise a first voltage detection unit, a second voltage detection unit, a rear module, a battery management system, a domain controller, a power battery, a DC/DC module and a low-voltage storage battery, wherein the detection end of the first voltage detection unit is connected with a normal fire power supply of the pure electric vehicle, the output end of the first voltage detection unit is connected with the rear module, the detection end of the second voltage detection unit is connected with the normal fire power supply of the pure electric vehicle, the output end of the second voltage detection unit is connected with the domain controller, the input end of the battery management system is connected with the rear module, the output end of the battery management system is connected with the DC/DC module and the low-voltage storage battery in sequence, and the output end of the domain controller is connected with the DC/DC module, wherein the rear module and the domain controller are original configurations on the pure electric vehicle. Compared with the prior art, the invention directly utilizes the rear module and the domain controller which are originally configured for the whole vehicle to automatically charge the low-voltage storage battery, thereby avoiding the power shortage of the low-voltage storage battery, reasonably utilizing the existing resources and saving the cost.

Inventors

LOU ZHIJUN
REN TIANLIANG
CAI JINGCHENG
PENG XILONG
ZHAO RUIFENG
Liu lv
PAN CHENGJIE
LI ZHONGYUAN

Assignees

中车时代电动汽车股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241107

Claims (5)

1. The low-voltage storage battery power supply system of the pure electric vehicle is characterized by comprising a first voltage detection unit, a second voltage detection unit, a rear module, a battery management system, a domain controller, a power battery, a DC/DC module and a low-voltage storage battery; the detection end of the first voltage detection unit is connected with a normal fire power supply of the pure electric vehicle, and the output end of the first voltage detection unit is connected with the rear module; The detection end of the second voltage detection unit is connected with a normal fire power supply of the pure electric vehicle, and the output end of the second voltage detection unit is connected with the domain controller; the input end of the battery management system is connected with the rear module, and the output end of the battery management system is connected with the domain controller; The power battery is connected with the DC/DC module, and the DC/DC module is connected with the low-voltage storage battery; the output end of the domain controller is connected with the DC/DC module; The rear module and the domain controller are original configurations on the pure electric vehicle.
2. The electric vehicle low-voltage battery power supply system of claim 1, wherein the domain controller is electrically connected with the source of normal thermal power through a first switch.
3. The low-voltage storage battery power supply system of a pure electric vehicle according to claim 1 or 2, wherein hard wire connection is adopted between the rear module and the battery management system and between the battery management system and the domain controller.
4. A control method of the low-voltage battery recharging system of a pure electric vehicle as claimed in any one of claims 1 to 3, comprising the steps of: when the first switch is disconnected, if the rear module detects that Chang Huo voltage of the normal fire power supply is less than 24V, the rear module wakes up the BMS through a hard wire, the BMS wakes up the VCU through the hard wire, and the VCU controls the DC/DC module to charge the low-voltage storage battery; When the first switch is closed, the rear module detects that the first gear signal is effective, no signal is output, and when the VCU detects that Chang Huo voltage of the normal fire power supply is less than 24V, the VCU controls the DC/DC module to charge the low-voltage storage battery.
5. The method of claim 4, wherein the VCU is powered up for 1h, the VCU first powers down the power flow, then the VCU control back module stops outputting, the BMS wakes up to disconnect, and the VCU is powered down.

Description

Low-voltage storage battery electricity supplementing system of pure electric vehicle and control method thereof Technical Field The invention relates to the technical field of new energy vehicles, in particular to a low-voltage storage battery electricity supplementing system of a pure electric vehicle and a control method thereof. Background The battery control units of the pure electric vehicles are more, and the overall static current is larger. When a low-voltage battery equipped in a pure electric vehicle is in a low-voltage state, the voltage thereof is lower than the normal-state voltage. The low voltage of the low voltage battery cannot wake up the vehicle-mounted device and the control unit, and the vehicle-mounted device and the control unit cannot work normally, and the vehicle cannot be started. Under 24h monitoring state or normal fire state, the pure electric vehicle can continuously consume the electric quantity of the low-voltage storage battery, so that the whole vehicle is deficient in electricity. After the low-voltage storage battery is deficient in power, the power battery cannot be utilized to supplement power. Because the power battery charges (supplements electricity) the 24V low-voltage storage battery through the DC/DC module, a Battery Management System (BMS) of the power battery is in a working state, and the main positive relay and the main negative relay are in attraction. The BMS can not be awakened after the low-voltage storage battery is deficient in power, enough voltage can not be provided to enable the relay to be attracted, so that the power battery can not form a high-voltage closed loop, the low-voltage storage battery can not be charged, and the normal starting of the pure electric vehicle is affected. Disclosure of Invention The invention provides a low-voltage storage battery power supply system of a pure electric vehicle and a control method thereof, which are used for solving the technical problem that the normal starting of the pure electric vehicle is affected by the low-voltage storage battery equipped in the existing pure electric vehicle due to power deficiency. In order to achieve the above purpose, the present invention adopts the following technical scheme. A battery system for supplementing low-voltage storage battery of pure electric vehicle comprises a first voltage detection unit, a second voltage detection unit, a rear module, a battery management system, a domain controller, a power battery, a DC/DC module and a low-voltage storage battery; the detection end of the first voltage detection unit is connected with a normal fire power supply of the pure electric vehicle, and the output end of the first voltage detection unit is connected with the rear module; The detection end of the second voltage detection unit is connected with a normal fire power supply of the pure electric vehicle, and the output end of the second voltage detection unit is connected with the domain controller; the input end of the battery management system is connected with the rear module, and the output end of the battery management system is connected with the domain controller; The power battery is connected with the DC/DC module, and the DC/DC module is connected with the low-voltage storage battery; the output end of the domain controller is connected with the DC/DC module; The rear module and the domain controller are original configurations on the pure electric vehicle. Therefore, when the first voltage detection unit detects that the voltage of the normal fire power supply is lower than a preset value (24V), the rear module wakes up the battery management system BMS, the battery management system BMS wakes up the domain controller VCU, and the domain controller VCU controls the DC/DC module to charge the low-voltage storage battery, so that the low-voltage storage battery is prevented from being deficient. On the other hand, the invention directly utilizes the rear module and the domain controller which are originally configured in the whole vehicle to realize the automatic charging of the low-voltage storage battery, reasonably utilizes the existing resources and saves the cost. In some embodiments, the domain controller is electrically connected to the source of thermal energy via a first switch. In some embodiments, a hard-wired connection is employed between the rear module and the battery management system, and between the battery management system and the domain controller. Therefore, the invention wakes up the domain controller through the hard wire signal, reduces the load rate of the CAN bus and enhances the reliability. Based on the same inventive concept, the invention also provides a control method of the low-voltage storage battery power supply system of the pure electric vehicle, which comprises the following steps: when the first switch is disconnected, if the rear module detects that Chang Huo voltage of the normal fire power supply is less than 24V, the re