CN-122008863-A - Vehicle-mounted low-voltage power supply lithium battery and power supply system

CN122008863ACN 122008863 ACN122008863 ACN 122008863ACN-122008863-A

Abstract

The invention discloses a vehicle-mounted low-voltage power supply lithium battery and a power supply system, which solve the problem of continuous switching of vehicle-mounted low-voltage charging and discharging and avoid damage of a storage battery caused by floating charging and overvoltage. The technical scheme is that a relay and a diode are matched to control the charge and discharge modes of the lithium battery system, so that continuous charge and discharge switching can be realized. The lithium battery supplies power to the load through two paths of redundancy, so that the reliability of low-voltage power supply of the system is ensured. After the vehicle-mounted charger is started, the lithium battery enters a floating charge state, so that the electric quantity of the battery in an emergency condition can meet the low-voltage load requirement of the whole vehicle. When the lithium battery is about to float and fully charged, the current flowing direction of the lithium battery is controlled through the cooperation of the relay and the diode, so that the damage of the service life of the battery caused by overcharging of the storage battery in the float charging process can be avoided, and the battery can be in a hot standby state to ensure the timeliness of discharging.

Inventors

CAO JINGBIN
LUO MINGYU
LIU XIONGWEI
LI JIYUAN
DONG QIAI
LUO HUANG
SU AIJUN
ZOU BIN
LI HAO
SU JING
GUO JINGJIANG
LI DAWEI

Assignees

湖南中车智行科技有限公司

Dates

Publication Date: 20260512
Application Date: 20241107

Claims (5)

1. The system comprises a vehicle-mounted charger, a vehicle-mounted load, a lithium battery, a battery management system, a relay and a diode, wherein the diode comprises a first diode, a second diode and a third diode, the relay comprises a first relay and a second relay, a control end of the first relay and a control end of the second relay are connected with the battery management system, the third diode and the second diode are sequentially connected in series between the vehicle-mounted charger and the vehicle-mounted load, an anode of the third diode is connected with the vehicle-mounted charger, a cathode of the second diode and a cathode of the first diode are both connected with the vehicle-mounted load, a contact of the first relay is connected with the cathodes of the lithium battery and the third diode, and a contact of the second relay is connected with anodes of the lithium battery and the first diode.
2. The vehicle-mounted low-voltage power supply lithium battery and the power supply system according to claim 1, wherein the battery management system performs self-checking, and enters a discharging mode after a discharging condition is met, the battery management system controls the first relay and the second relay to be closed, the lithium battery supplies power to the vehicle-mounted load through two paths of redundancy, and the power supply of the vehicle-mounted load is completely provided by the lithium battery.
3. The vehicle-mounted low-voltage power supply lithium battery and the power supply system according to claim 1, wherein when the vehicle is at high voltage, the battery management system sends required charging voltage and charging current to the vehicle-mounted charger, the first relay and the second relay are kept closed, the vehicle-mounted charger charges the lithium battery through the first branch and supplies power to the vehicle load through the second diode, the lithium battery is not discharged under the reverse cut-off effect of the first diode of the second branch, and the vehicle load is supplied with power by the charger.
4. The vehicle-mounted low-voltage power supply lithium battery and the power supply system according to claim 1, wherein when the lithium battery is about to be fully charged and the vehicle-mounted charger is turned to a voltage stabilizing state, the battery management system controls the first relay to be opened, the second relay is kept closed, and the second relay is matched with the first diode to discharge through the second branch, so that the storage battery is in a chargeable and unchangeable hot standby state.
5. The vehicle-mounted low-voltage power supply lithium battery and power supply system according to claim 1, wherein the second relay is in a closed state when the vehicle is under high voltage, the lithium battery supplies power to the vehicle-mounted load through the second branch, when the second branch is detected to have current and the first branch is not current, the first relay is closed, and the lithium battery resumes that both the first branch and the second branch supply power to the vehicle-mounted load.

Description

Vehicle-mounted low-voltage power supply lithium battery and power supply system Technical Field The invention relates to the field of novel electric vehicles for urban traffic, in particular to a vehicle-mounted low-voltage power supply lithium battery and a power supply system, which are mainly applied to low-voltage power supply of novel electric vehicles, can meet the requirement that the charging and discharging of the low-voltage lithium battery can be switched at any time, and can avoid the damage of a storage battery caused by floating charging overvoltage. Background Along with the rapid development of the intelligent technology, the intelligent power supply system is increasingly widely and deeply applied to the field of new energy vehicles, so that the intelligent level of the vehicles is greatly improved, and more stringent requirements are also provided for vehicle-mounted low-voltage uninterruptible power supply systems. Conventional lead-acid batteries, while playing a significant role in the past automotive electrical systems, have inherent limitations that are increasingly evident under challenges. In particular, intelligent new energy vehicles require more powerful power support to drive complex electronic control systems, advanced Driving Assistance Systems (ADAS), infotainment systems, and increasingly on-board sensors, etc. These systems are not only power consuming, but also have extremely high requirements for stability and continuity of power supply. However, lead-acid batteries have difficulty meeting long-term, high-load power supply demands due to their relatively low capacity density. Even if the basic power supply requirements can be met, the weight and the volume of the lead-acid storage battery become a big obstacle for the lightweight design of the new energy vehicle. The light weight is one of key factors for improving energy efficiency and prolonging endurance mileage of new energy vehicles. Due to material and technical limitations, the traditional lead-acid storage battery is heavy, occupies valuable loading space of the vehicle, and is unfavorable for improving the overall performance and user experience of the vehicle. Therefore, under the background of increasing intelligent demands of new energy vehicles, the requirement of light-weight indexes of the traditional lead-acid storage battery is difficult to meet. Disclosure of Invention The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later. The invention aims to solve the problems, and provides a vehicle-mounted low-voltage power supply lithium battery and a power supply system, which solve the problem of continuous switching of vehicle-mounted low-voltage charging and discharging and avoid damage of a storage battery caused by floating charging overvoltage. The invention discloses a vehicle-mounted low-voltage power supply lithium battery and a power supply system, wherein the system comprises a vehicle-mounted charger, a vehicle-mounted load, a lithium battery, a battery management system, a relay and a diode, wherein the diode comprises a first diode, a second diode and a third diode, the relay comprises a first relay and a second relay, the control ends of the first relay and the second relay are connected with the battery management system, the third diode and the second diode are sequentially connected in series between the vehicle-mounted charger and the vehicle-mounted load, the anode of the third diode is connected with the vehicle-mounted charger, the cathode of the second diode and the cathode of the first diode are both connected with the vehicle-mounted load, the contact of the first relay is connected with the cathodes of the lithium battery and the third diode, and the contact of the second relay is connected with the anodes of the lithium battery and the first diode. According to the embodiment of the vehicle-mounted low-voltage power supply lithium battery and the power supply system, the battery management system performs self-checking, and enters a discharging mode after the discharging condition is met, the battery management system controls the first relay and the second relay to be closed, the lithium battery supplies power to the vehicle-mounted load through two paths of redundancy, and the power supply of the vehicle-mounted load is completely provided by the lithium battery. According to the vehicle-mounted low-voltage power supply lithium battery and the embodiment of the power supply system, after a vehicle is at high voltage, the battery management system sends required chargi