Battery management system

Abstract

The invention belongs to the technical field of new energy vehicles, and provides a battery management system. Comprising a signal acquisition module, a central processor module, a control module and a display module, the signal acquisition module is used for monitoring the working state of a single battery in a vehicle battery pack; the central processing unit module is used for processing the system information uploaded by the bus, comparing the system information with the optimal system operation state parameters stored in the high-capacity data memory, and analyzing and processing the collected battery data; the central processor module is also used for judging whether the single battery is abnormal or not according to the working state, and sending an abnormal control signal to the control module when the detected single battery is abnormal; the control module is used for stopping the abnormal single battery according to the abnormal control signal; the display module is used for displaying state quantity of the battery pack. The maintenance effect of the battery is greatly improved, and the service life of the battery pack is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicles, and in particular relates to a battery management system. Background Art

[0002] The battery pack of an electric vehicle usually contains dozens or even hundreds of cells. Lithium batteries or nickel-metal hydride batteries may have hundreds of cells. The working voltage is usually around 300V, and the working current is as high as several hundred amperes. Battery packs generally work in series, and the working current is the same as that of the cells, so detection is relatively easy, while detection of the terminal voltage is more difficult. If you only detect the terminal voltage of the battery pack, the method is very simple. You only need to connect the detection circuit at both ends of the battery pack. However, this is not feasible because although the total working voltage can be obtained, the terminal voltage of a specific cell cannot be determined. As long as there is a problem with one battery, the normal operation and performance of the entire battery pack will be affected.

[0003] CN103124086A discloses a battery management system for an electric vehicle, wherein a monitoring module is used to monitor the status of a battery pack and a battery management system in real time, and to send abnormal status data of the battery pack and / or the battery management system when the status of the battery pack and / or the battery management system is abnormal. However, the status of each battery cannot be monitored, and when a battery pack fails, a single battery cannot be accurately located. Summary of the invention

[0004] The present invention aims at solving the deficiencies in the prior art and provides a battery management system.

[0005] The present invention is achieved through the following technical solutions:

[0006] Signal acquisition module, central processing unit module, control module and display module;

[0007] The signal acquisition module is used to monitor the working status of the single cells in the vehicle battery pack;

[0008] The central processing unit module is used to process the system information uploaded from the bus, and compare it with the system operation optimal state parameters stored in the large-capacity data storage device. The central processing unit module analyzes and processes the collected battery data;

[0009] The central processing unit module is also used to determine whether the single battery is abnormal according to the working state, and send an abnormal control signal to the control module when the detected single battery is abnormal;

[0010] The control module is used to disable the abnormal single battery according to the abnormal control signal;

[0011] The display module is used to display the status of the battery pack.

[0012] Furthermore, the signals that the signal acquisition module needs to acquire include: voltage signals, current signals and temperature signals.

[0013] Furthermore, the voltage signal is collected by the battery management system to collect the voltage signal of each single battery.

[0014] Furthermore, the signal acquisition module selects the single cells to be tested in turn through the linear optocoupler switch, and collects voltage data through the sampling and holding circuit and A / D conversion.

[0015] Furthermore, the current signal is collected by the battery management system to collect the charging current and discharging current of the battery pack, and a shunt meter is used to collect current data.

[0016] Furthermore, the temperature signal is collected by using a temperature sensor to collect temperature data.

[0017] Furthermore, the temperature signal is collected taking into account the accuracy and reliability of the temperature. The battery box is provided with 10 temperature collection points which are evenly distributed on the battery cells to be tested in the battery box.

[0018] Furthermore, the CAN network sends the processed battery data to the CAN master node to achieve dynamic measurement of various parameters on the vehicle.

[0019] Furthermore, the signal acquisition module and the central processing unit module communicate with each other through the CAN network to achieve sharing of sensor measurement data and sending and receiving of control instructions.

[0020] Furthermore, the signal acquisition module monitors and collects the temperature and voltage of each single battery, communicates with the central processing unit module through the CAN network, and transmits the battery pack SOC, temperature and voltage parameters to the central processing unit module in real time.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] Battery management system has always been an important technology in the development of electric vehicles. The most basic function of the battery pack management system is to monitor the battery working status (battery voltage, current and temperature). By measuring these parameters, the battery SOC and the corresponding remaining maximum mileage can be predicted, and the battery working conditions can be managed (avoiding over-discharge, over-charging, overheating and serious voltage imbalance between single cells) in order to maximize the use of battery storage capacity and increase cycle life.

[0023] The vehicle network data acquisition system based on the STM32 chip developed by the present invention for electric cars has been proved to be able to detect the state of the battery pack and display the SOC of the battery pack in real time and accurately through actual use on the car, and to verify the stability, anti-interference ability and timely and accurate communication of the CAN bus. Through software and hardware filtering, optical coupling isolation and other measures, the accuracy and stability of the collected signal are guaranteed, and the reliability of the system is enhanced. Therefore, the battery management system greatly improves the maintenance effect of the battery and prolongs the life of the battery pack.

[0024] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 shows the overall block diagram of the battery management system;

[0027] Figure 2 is a hardware block diagram showing a battery management system. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Battery management system has always been an important technology in the development of electric vehicles. The most basic function of the battery pack management system is to monitor the battery working status including battery voltage, current and temperature. By measuring these parameters, the battery SOC and the corresponding remaining maximum mileage can be predicted, and the battery working conditions can be managed to avoid over-discharge, over-charging, overheating and serious voltage imbalance between single cells, so as to maximize the use of battery storage capacity and increase cycle life.

[0030] The vehicle network data acquisition system based on the STM32 chip developed by the present invention for electric cars has been proved to be able to detect the state of the battery pack and display the SOC of the battery pack in real time and accurately through actual use on the car, and to verify the stability, anti-interference ability and timely and accurate communication of the CAN bus. Through software and hardware filtering, optical coupling isolation and other measures, the accuracy and stability of the collected signal are guaranteed, and the reliability of the system is enhanced. Therefore, the battery management system greatly improves the maintenance effect of the battery and prolongs the life of the battery pack.

[0031] Specifically, Figure 1 As shown, a control system based on a battery management system includes:

[0032] The control system based on the battery management system uses STM32F103VB as the core chip of the system. The port voltage is collected and monitored through the chip's built-in 12-bit ADC, and the collected data is sent to the car dashboard through the CAN network, providing a data source for real-time monitoring of vehicle data.

[0033] The reason why the present invention selects the STM32F103VB chip is that this chip has a CAN interface and an ADC analog-to-digital converter, and almost all ports on the car are CAN interfaces. In addition, this acquisition system can realize dynamic detection of the status of multiple high-voltage batteries, and can be directly transmitted from the CAN port to the instrument for display without converting the data. The specific contents that can be detected include checking whether the battery is faulty, a certain battery has a low voltage, and finding out which battery has an abnormality.

[0034] The battery management system uses a microcontroller that integrates the CAN controller module STM32 chip platform, and is built on a PCB board. The embedded single-chip microcomputer is composed of a high-performance microprocessor as the core, with a program and data memory that occupies a large storage space and a CAN bus interface. It can quickly process the system information uploaded from the bus, and the large-capacity data memory stores the system's optimal operating state parameters, so that the processor can timely and accurately analyze and process the weak variables of the collected battery data according to the control strategy.

[0035] The battery management system collects the current status parameters (voltage, capacity, temperature) of each battery pack, and processes this information and sends it to the master node through the CAN network to achieve dynamic measurement of various parameters on the vehicle. At the same time, the battery pack status will also be transmitted to the display unit for display.

[0036] The control system based on the battery management system includes a signal acquisition module, a central processing unit module and a display module.

[0037] The signal acquisition module effectively detects the power and temperature of each battery in the battery pack, and checks whether a battery is low in power or faulty, to prevent the entire battery system from crashing due to a battery being too low in power or faulty and unable to work properly.

[0038] As shown in the table below, the signal acquisition module manages the battery pack of the electric vehicle and detects the voltage, capacity and temperature parameters of the battery. For example, factors such as low battery power, high battery temperature, long use time and short circuit that may cause the electric vehicle to be unable to drive normally can serve as an alarm for dangerous signals that are about to occur or have already occurred.

[0039] Battery Management System Module Function Signals collected by the sensor Actuator Battery protection module Prevent overcharge, over discharge and over current Voltage, current Charger and motor power converter Battery detection module Monitor the working status of the battery Voltage, current, temperature Display device SOC Module Predict the SOC value of the current Voltage, current, temperature Display device Balanced charge and discharge module Balanced management of battery charge and discharge Voltage, current Equalizer

[0040] The signals that the signal acquisition module needs to collect include: voltage signal, current signal and temperature signal.

[0041] 1) Voltage signal acquisition: The battery management system needs to acquire the voltage signal of each single battery. The signal acquisition module selects the battery cells to be tested in turn through the linear optocoupler switch, passes through the sample-and-hold circuit, and acquires the voltage data through A / D conversion.

[0042] 2) Collection of current signals: The system only needs to collect the charge and discharge current of the entire battery box, so a shunt meter is used to collect current data.

[0043] 3) Temperature signal collection: A temperature sensor is used to collect temperature data. Taking into account the accuracy and reliability of the temperature, 10 temperature collection points are set in the battery box, evenly distributed on the battery cells to be tested in the battery box.

[0044] The basic processing method of the signal acquisition module of the present invention is that the peripheral circuit provides a reference voltage value, converts the collected voltage state quantity into a voltage value, and transmits the obtained data to the instrument through the CAN interface for display by comparing the two.

[0045] When a single cell is abnormal, the identification code of the single cell is added to the abnormal control signal. The control module determines the abnormal single cell through the identification code and disables the single cell. Specifically, the identification code can be a serial number obtained by pre-sorting the single cells.

[0046] In this embodiment, the central processing unit module can determine whether the single cell is abnormal through parameters such as voltage value, output power stability, current value, etc. in the working state.

[0047] In this embodiment, deactivation of an abnormal single cell battery can be achieved through a control module composed of a controller and a control switch set on each single cell battery circuit. Specifically, after receiving an abnormal control signal, the controller determines that an abnormal single cell battery has occurred, and controls the control switch connected in series with the single cell battery to disconnect, so that the single cell battery is separated from the battery pack as a whole, so as to achieve deactivation and ensure the safety of the battery pack as a whole.

[0048] In the present embodiment, deactivation of an abnormal single cell battery can also be achieved through a control module composed of a controller and control switches arranged on each battery pack circuit. Specifically, after receiving an abnormal control signal, the controller determines that an abnormal single cell battery has occurred, and controls the control switch connected in series with the battery pack corresponding to the single cell battery to be disconnected, so as to deactivate the single cell battery and ensure the safety of other battery packs.

[0049] The signal acquisition module and the central processing unit communicate through the CAN bus to achieve the sharing of sensor measurement data, the sending and receiving of control instructions, etc., and improve the control performance of each, thereby improving the control performance of the system. The communication and information types between them are information type and command type.

[0050] The management system involved in the present invention is applied to the whole vehicle distributed CAN network of a battery electric vehicle to collect and store the node data on the whole CAN network.

[0051] The signal acquisition module monitors and collects the temperature and voltage of each single battery, communicates with the central processing unit module through the CAN bus, and transmits the battery pack SOC, temperature, voltage and other parameters to the central processing unit module in real time.

[0052] The control system transmits the status of the battery pack to the display module for display.

[0053] like Figure 2 As shown, the hardware of the battery management system is mainly divided into a microcontroller minimum system, a signal acquisition circuit, a power circuit, a photoelectric isolation circuit, a single cell voltage signal, a power module, a patrol circuit, a central processing unit, CAN communication and B serial port communication, and an extended EEPROM circuit.

[0054] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery management system, characterized in that: include: Signal acquisition module, central processing unit module, control module and display module; The signal acquisition module is used to monitor the working status of the single cells in the vehicle battery pack; The central processing unit module is used to process the system information uploaded from the bus, and compare it with the system operation optimal state parameters stored in the large-capacity data storage device. The central processing unit module analyzes and processes the collected battery data; The central processing unit module is also used to determine whether the single battery is abnormal according to the working state, and send an abnormal control signal to the control module when the detected single battery is abnormal; The control module is used to disable the abnormal single battery according to the abnormal control signal; The display module is used to display the status of the battery pack.

2. The management system according to claim 1, characterized in that: Signal acquisition module, including: The signals that the signal acquisition module needs to acquire include: voltage signal, current signal and temperature signal.

3. The management system according to claim 2, characterized in that: Voltage signals, including: The voltage signal is collected by the battery management system, which needs to collect the voltage signal of each single battery.

4. The management system according to claim 3, characterized in that: Voltage signals, including: The signal acquisition module selects the single cells to be tested in turn through the linear optocoupler switch, and collects the voltage data through the sample-and-hold circuit and A / D conversion.

5. The management system according to claim 2, characterized in that: Current signals, including: The current signal is collected by the battery management system to collect the charging current and discharging current of the battery pack, and a shunt meter is used to collect current data.

6. The management system according to claim 2, characterized in that: Temperature signals, including: The temperature signal is collected by using a temperature sensor to collect temperature data.

7. The management system according to claim 6, characterized in that: include: The acquisition of temperature signals takes into account the accuracy and reliability of temperature. The battery box is equipped with 10 temperature acquisition points, which are evenly distributed on the battery cells to be tested in the battery box.

8. The management system according to claim 1, characterized in that: include: The CAN network sends the processed battery data to the CAN master node to achieve dynamic measurement of various parameters on the vehicle.

9. The management system according to any one of claims 1 to 8, characterized in that: include: The signal acquisition module and the central processing unit module communicate with each other through the CAN network to realize the sharing of sensor measurement data and the sending and receiving of control instructions.

10. The management system according to any one of claims 1 to 8, characterized in that: include: The signal acquisition module monitors and collects the temperature and voltage of each single battery, communicates with the central processing unit module through the CAN network, and transmits the battery pack SOC, temperature and voltage parameters to the central processing unit module in real time.

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