CN215601049U

CN215601049U - Battery management system and bus system

Info

Publication number: CN215601049U
Application number: CN202120123903.4U
Authority: CN
Inventors: 袁尧; 胡金龙; 梁浩
Original assignee: Huaian Zhongke Jingshang Intelligent Network Research Institute Co ltd
Current assignee: Huaian Zhongke Jingshang Intelligent Network Research Institute Co ltd
Priority date: 2020-09-11
Filing date: 2021-01-15
Publication date: 2022-01-21
Anticipated expiration: 2031-01-15

Abstract

The utility model discloses a battery management system and a bus system. The system management of the lead-acid battery can be realized by using the utility model. The battery management system and the bus system utilize a patent management chip of a lithium battery, namely a device of an American mail MAX14921 battery measurement analog front end AFE to design a battery management system BMS. The battery management system BMS may sample the battery voltage with high accuracy and provide level conversion to monitor 4 lead-acid batteries of a 48V electric bicycle.

Description

Battery management system and bus system

Technical Field

The utility model relates to the technical field of hardware circuits, in particular to a battery management system and a bus system.

Background

Lead-acid batteries also present many problems as a core component of electric bicycles. For example, lead-acid batteries are often in a heavy-current discharge state and are prone to overdischarge; various differently configured chargers cause the lead acid battery to be under-charged or over-charged. Both of these problems lead to a significant reduction in the life of lead acid batteries. More dangerously, the problem of uncontrolled temperature can cause fire to occur, seriously affecting daily safety.

To date, there is no management chip for lead-acid batteries; therefore, it is very necessary to develop a battery management system for lead-acid batteries.

Disclosure of Invention

In view of this, the present invention provides a battery management system and a bus system, which can manage a lead-acid battery.

In order to achieve the purpose, the technical scheme of the utility model is as follows: a battery management system comprises a DCDC voltage reduction power supply, an AFE chip, an LDO low dropout regulator, an MCU (micro control unit), a current shunt monitor, a 485 transceiver and a lead-acid battery.

The DCDC voltage reduction power supply is connected with the AFE chip for power supply on one hand, and is connected with the LDO low dropout linear regulator on the other hand for providing voltage for the MCU micro control unit and the current shunt monitor. And the current shunt monitor is connected with the MCU. The AFE chip is connected with the lead-acid battery and is connected with the MCU. The MCU micro control unit is connected with the AFE chip through the SPI interface, and transmits the state information of the lead-acid battery to the server through the 485 transceiver so as to reach the user. The 485 transceiver is connected with the micro control unit and used for communicating with an external system.

Furthermore, the lead-acid battery at most comprises a first battery, a second battery, a third battery and a fourth battery.

Furthermore, the AFE chip is connected with the lead-acid battery, the positive electrode of the first battery is connected with a CV4 port of the AFE chip, the negative electrode of the first battery is connected with a CV0 port of the AFE chip, and the negative electrode of the first battery is the negative electrode of the lead-acid battery.

The positive electrode of the second battery is connected with the CV8 port of the AFE chip, and the negative electrode is connected with the positive electrode of the first battery.

The positive electrode of the third battery section is connected with the CV12 port of the AFE chip, and the negative electrode of the third battery section is connected with the positive electrode of the second battery section. The positive electrode of the fourth battery is connected with a CV16 port of the AFE chip, the negative electrode of the fourth battery is connected with the positive electrode of the third battery, and the positive electrode of the third battery is the positive electrode of the lead-acid battery. And the ground GND and CT1 ports of the AFE chip, the CB2 and CT2 ports of the AFE chip, the CB3 and CT3 ports of the AFE chip and the like are connected with sampling capacitors between each two ports till the CB16 and CT16 ports of the AFE chip.

Furthermore, the sampling capacitor is 1 muF, the CTn port of the AFE chip is the high end of the sampling capacitor, the CBn port is the low end of the sampling capacitor, and the value of the parameter n is an integer in the range of [1,16 ].

Further, when SAMPL is logic high, the inside of the CTn port of the AFE chip is connected to port CVn of the AFE chip to track CVn the input voltage, where the parameter n is an integer in the range of [1,16 ].

Furthermore, the T1, T2 and T3 ports of the AFE chip are single-ended, and are used for detecting the temperature of a single lead-acid battery by taking the CV0 port as a general analog input for reference.

Furthermore, the AFE chip has a thermal shutdown function, and in a thermal shutdown mode, the amplifier and the charge balance stop working, and the SPI interface works normally.

Further, the AFE chip measures the analog front end device for the meixin MAX14921 battery.

A bus system of a battery management system comprises a 485 bus, a controller, a communication positioning module, a server and at least one battery management system. The battery management system is connected to the 485 bus through a 485 transceiver therein. The controller is responsible for the driving motor of the battery car and is connected with a 485 bus. The communication positioning module is responsible for wireless communication and is connected with the 485 bus. The server is connected with the communication positioning module and used as a data platform for receiving the information transmitted by the communication positioning module. The battery management system internally communicates with the 485 bus through a well-defined protocol.

Has the advantages that: the battery management system and the bus system utilize a patent management chip of a lithium battery, namely a device of an American mail MAX14921 battery measurement analog front end AFE to design a battery management system BMS for managing a lead-acid battery. The battery management system can sample the voltage of the battery with high precision and provide level conversion so as to monitor 4 lead-acid batteries of the 48V electric bicycle. Meanwhile, the battery management system can achieve the effects of over-discharge protection, over-current protection, over-charge protection, temperature protection and short-circuit protection on the lead-acid battery, and realize the functions of voltage equalization, fault alarm and the like.

Drawings

Fig. 1 is a diagram illustrating a battery management system according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of an AFE chip for battery measurement according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a lead-acid battery management system according to an embodiment of the present invention.

Detailed Description

The utility model is described in detail below by way of example with reference to the accompanying drawings.

As shown in fig. 1, the battery management system is a constituent structure of the battery management system. The battery management system comprises a DCDC voltage reduction power supply, an AFE chip, an LDO low dropout regulator, an MCU (micro control unit), a current shunt monitor, a 485 transceiver and a lead-acid battery.

The DCDC voltage reduction power supply is connected with the AFE chip for power supply on one hand, and is connected with the LDO low dropout linear regulator on the other hand, and provides 3.3V voltage for the MCU micro control unit and the current shunt monitor.

The current shunt monitor is connected with the MCU, and the AFE chip is connected with the lead-acid battery and is connected with the MCU. The MCU micro control unit is connected with the AFE chip through the SPI interface, and transmits the state information of the lead-acid battery to the server through the 485 transceiver so as to reach the user. The 485 transceiver is connected with the micro control unit and used for communicating with an external system.

As shown in fig. 2, the AFE chip monitors the circuit of 4 lead-acid batteries. The same voltage dividing resistance is arranged between CV0 and CV1, and between CV1 and CV2 … …, CV15 and CV16, and is used for dividing the voltage of the lead acid battery to be tested. The CV0 is connected with the negative electrode of the first battery, namely the negative electrode of the whole battery pack, and the CV4 is connected with the positive electrode of the first battery; the cathode of the second battery is connected with the anode of the first battery, and CV8 is connected with the anode of the second battery; the negative electrode of the third battery is connected with the positive electrode of the second battery, and CV12 is connected with the positive electrode of the third battery; the negative electrode of the fourth battery is connected with the positive electrode of the third battery, and the CV16 is connected with the positive electrode of the fourth battery, namely the positive electrode of the whole battery pack. Therefore, each lead-acid battery comprises 4 sampling intervals, the sum of the voltages of the 4 sampling intervals is the real-time voltage of each lead-acid battery, and the connection can meet the maximum 16V differential pressure of the lead-acid battery. 1uF sampling capacitors are connected between the ground line (GND) and the CT1, and between the CB2 and the CT2 … …, and between the CB16 and the CT16, wherein CTn is the high end of the sampling capacitors, and CBn is the low end of the sampling capacitors. With SAMPL logic high, CTn is internally connected to CVn, tracking CVn the input voltage. The T1, T2 and T3 inputs are single-ended, and are general analog inputs with CV0 as a reference, and are used for monitoring the temperature of a single lead-acid battery.

Furthermore, the AFE chip is an American standard MAX14921 battery measurement analog front-end device, and has a thermal shutdown function, and in a thermal shutdown mode, the amplifier and the charge balance circuit stop working, and the SPI interface works normally.

As shown in fig. 3, the system communicates with the inside of the system through a 485 bus with a defined protocol, and can be connected with a plurality of battery management systems; the controller is responsible for the driving motor of storage battery car, and battery management system is responsible for the management of power lead-acid batteries, and communication orientation module is responsible for wireless communication, uploads this data platform of server with the information. The battery management system collects the state information of the single battery in the module through the AFE chip, and sends the state information to the MCU after analysis and processing, and the MCU can control the AFE chip through the SPI interface. Data are transmitted through 485 communication and then uploaded to a server through a communication module so as to reach a user, and the remote real-time monitoring of the lead-acid battery is realized.

In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery management system, comprising: the device comprises a DCDC voltage reduction power supply, an AFE chip, an LDO low dropout linear regulator, an MCU (micro control unit), a current shunt monitor, a 485 transceiver and a lead-acid battery;

the DCDC voltage reduction power supply is connected with the AFE chip for power supply on one hand, and is connected with the LDO low dropout linear regulator on the other hand, and provides voltage for the MCU micro control unit and the current shunt monitor;

the current shunt monitor is connected with the MCU;

the AFE chip is connected with the lead-acid battery and is connected with the MCU;

the MCU is connected with the AFE chip through an SPI interface, and the state information of the lead-acid battery is transmitted to a server through the 485 transceiver so as to reach a user;

the 485 transceiver is connected with the micro control unit and used for communicating with an external system.

2. The system of claim 1, wherein the lead-acid battery comprises at most a first battery, a second battery, a third battery, and a fourth battery.

3. The system of claim 2, wherein the AFE chip is coupled to the lead-acid battery, the positive electrode of the first battery is coupled to the CV4 port of the AFE chip, the negative electrode is coupled to the CV0 port of the AFE chip, and the negative electrode of the first battery is the negative electrode of the lead-acid battery;

the positive electrode of the second battery is connected with a CV8 port of the AFE chip, and the negative electrode of the second battery is connected with the positive electrode of the first battery;

the positive electrode of the third battery is connected with the CV12 port of the AFE chip, and the negative electrode of the third battery is connected with the positive electrode of the second battery;

the positive electrode of the fourth battery is connected with a CV16 port of the AFE chip, the negative electrode of the fourth battery is connected with the positive electrode of the third battery, and the positive electrode of the third battery is the positive electrode of the lead-acid battery;

and the ground GND and CT1 ports of the AFE chip, the CB2 and CT2 ports of the AFE chip, the CB3 and CT3 ports of the AFE chip and the like are connected to the sampling capacitors between the CB16 and CT16 ports of the AFE chip.

4. The circuit of claim 3, wherein the sampling capacitor is a 1 μ F sampling capacitor, the CTn port of the AFE chip is the high end of the sampling capacitor, the CBn port is the low end of the sampling capacitor, and wherein the parameter n is an integer in the range of [1,16 ].

5. The circuit of claim 3 wherein SAMPL is logic high, and wherein the CTn port of the AFE chip is internally connected to port CVn of the AFE chip, tracking CVn the input voltage, wherein the parameter n takes on an integer value in the range of [1,16 ].

6. The circuit of claim 3, wherein the ports T1, T2 and T3 of the AFE chip are single-ended, and are general-purpose analog inputs referenced to port CV0 for temperature detection of a single lead-acid battery.

7. The circuit of claim 3, wherein the AFE chip has a thermal shutdown function, in which an amplifier and a charge balance stop operating and the SPI interface operates normally.

8. The system of claim 1, wherein the AFE chip is an american standard MAX14921 battery measurement analog front end device.

9. A bus system for a battery management system, comprising at least one battery management system of claim 1, a 485 bus, a controller, a communication positioning module, a server;

the battery management system is connected to the 485 bus through a 485 transceiver in the battery management system;

the controller is responsible for driving a motor and is connected with the 485 bus;

the communication positioning module is in charge of wireless communication and is connected with the 485 bus;

the server is connected with the communication positioning module and used as a data platform for receiving the information transmitted by the communication positioning module;

the battery management system is internally communicated with the 485 bus through a defined protocol.