CN204597578U - A kind of serial lithium battery management system used for electric vehicle - Google Patents

Abstract

The utility model provides a kind of serial lithium battery management system used for electric vehicle, and management system comprises main controller module, battery pack control module, battery voltage sensing module, battery current detection module, data-storing module, temperature control module, display module, alarm module, power module and energy supply control module.Native system and management method thereof enough realize the voltage of whole lithium battery system, current acquisition, battery temperature control; Each battery pack control module has monomer battery voltage and temperature acquisition, balance charge/discharge controlling functions, system can be identified battery that in power brick, other battery pressure reduction is excessive and be realized the consistency of cell capacity by charge-discharge control circuit, cell is avoided to overcharge or charge less, reach lithium battery group balance charge/discharge, according to the history value estimation useful life of cell of voltage, charging or discharging current, temperature parameter and the matching degree with power brick, guarantee that lithium battery system is long-acting, run safely.

Description

A series lithium battery management system for electric vehicles

technical field

The utility model relates to the technical field of lithium battery power management, in particular to a series lithium battery management system for electric vehicles.

Background technique

The use of single cells in series can increase the output voltage of the battery pack, and the use of parallel connections can obtain greater battery capacity. In the power battery pack for electric vehicles, increasing the output voltage of the battery pack can improve the system efficiency, thereby reducing the total cost of electric vehicles. Because the voltage of a single battery is low and the capacity is limited, the method of obtaining a high-voltage large-capacity battery pack by connecting several single batteries in series and parallel is widely used in automotive power batteries. The state of the single battery and the length of life affect the performance of the vehicle. During the use of the power battery of an electric vehicle, the imbalance of the single battery is an important factor affecting the work of the battery pack, so it is very necessary to balance the battery pack.

Chinese patent 101814754A discloses a lithium battery pack power management system, which adopts a two-way control mode to control the charging tube and the discharging field tube, which can increase the stability and control accuracy of the system.

Chinese patent 201110421975.8 discloses a lithium battery charging power management method and system, which can determine whether to charge according to the lithium battery voltage detected when the input power is turned on, stop charging when the charging exceeds 10% of the rated voltage of the battery, and provide a charging The system can avoid affecting the life of the battery due to frequent charging and long-term full capacity of the lithium battery.

Chinese patent 201110335313.9 discloses a lithium battery pack management system for electric vehicles, which also adopts the form of a main control unit plus a bottom control unit, and its patent content is more inclined to the detection circuit design and balanced charging control of single batteries.

In the existing battery management system, most of the inventions are aimed at the voltage and current detection technology of the single battery and the balanced charging and discharging technology of the whole battery pack. There is a lack of research on the estimation and prediction of battery life; there is a lack of research on the control of power supply to various parts of the battery management system; there is a lack of research on the degree of matching of all cells in the entire battery pack.

The purpose of this utility model is to provide a series lithium battery management system for electric vehicles to fill the gaps in the prior art.

Utility model content

The technical problem to be solved by the utility model is the series lithium battery management system for electric vehicles, that is, to provide a control system with a master-slave structure based on Freescale single-chip microcomputer, which can accurately measure the voltage, current and temperature of the single battery. On the basis of this, a more accurate estimation of the capacity of the single battery can be realized, so as to realize the balanced charge and discharge control of the battery; on the basis of accurate measurement based on hardware, the software system can calculate the matching degree of the single battery in the entire battery pack and estimate the use of the battery life.

In order to achieve the above purpose, the technical solution adopted by the utility model is: a series lithium battery management system for electric vehicles, including a main controller module, 8 battery pack control modules, a battery voltage detection module, a battery current detection module, a temperature control module, display module, alarm module, power module and power control module.

The maximum range of applicable objects of the series lithium battery management system for electric vehicles is a battery system composed of 88 single lithium batteries in series, wherein 88 single lithium batteries form 8 lithium battery packs, and each lithium battery pack consists of 11 It consists of single cells connected in series.

Further, the main controller module has a CAN interface, and is connected to the 8 battery pack control modules through functional CAN communication pins to realize data exchange between multiple controllers.

Further, the main controller module and the display module are connected to each other through functional pins, and the nuclear power status of the entire battery system and the charging status of each single battery can be displayed under the operating status of the electric vehicle and the charging and discharging status of the battery system. Displayed on the screen, the user can query the matching degree of the battery and the service life of the battery through the screen.

Further, the PTD pin of the main controller module is connected to the function pin of the temperature control module, and the air cooling device is started in real time, so as to control the dangerous situation of the battery due to overheating caused by overheating during charging and discharging. .

Further, the main controller module and the alarm module are connected to each other through functional pins, so as to realize the alarm function of special situations that occur during short circuit, battery life limit, and battery charge and discharge. The utility model adopts the form of sound and light alarm .

Further, the main controller module and the power supply module are connected to each other through functional pins to realize the function of supplying power to the main controller module and other auxiliary circuits, and the power supply is provided by a battery pack or a vehicle battery. Realized by the power control module.

Further, the main controller module and the power control module are connected to each other through functional pins, and the power control module realizes the selection function between the battery pack and the vehicle belt battery through a switching circuit, and realizes the function of selecting between the battery pack and the vehicle belt battery through a logic circuit, and realizes the power control module in the parking state through a logic circuit. Non-stop wake-up capability to the main controller module.

Further, the power supply control module is connected to the power supply module through pins through a relay switch, so as to realize switching and switching functions of the power supply module.

Further, each battery pack control module includes a battery pack controller, a switching module, a charging and discharging module, a single battery temperature detection module, a single battery voltage detection module, a battery pack current detection module and a communication module.

Further, the battery pack controller and the switching module are connected to each other through function pins, and the charging and discharging selection function for a single battery is realized through a relay matrix and an optocoupler.

Further, the battery pack controller is connected to the battery pack temperature detection module, the battery pack voltage detection module and the battery pack current detection module respectively through function pins and the sampling module, so as to realize the monitoring of the temperature and voltage of the single battery pack. The measurement sampling and battery pack current detection and sampling functions provide a reliable data basis for estimating the battery capacity and ensure the safety and accuracy of the battery charging and discharging process.

Further, the battery pack controller and the charging and discharging module are connected to each other through pins, so as to realize the switching function during the charging and discharging process of the single battery.

Further, the battery pack controller and the communication module are connected to each other through pins to complete the CAN bus communication function with the main controller module.

Further, the switching module, the battery voltage detection module and the charging and discharging module are respectively connected to the positive and negative poles of each battery in the group through wires.

Further, the power control module is composed of a power switching module, a logic circuit, 12-12DC/DC module A, 12-12DC/DC module B, 12-5C/DC module A, 12-5DC/DC module B, 12 -5DC/DC module C, 12-5DC/DC module D.

Further, the power switching module is respectively connected with the vehicle storage battery, the battery pack and the 12-12DC/DC module A, 12-12DC/DC module B, 12-5C/DC module A, and 12-5DC/DC module B , and under the action of the control signal CRL1 of the main controller module, two types of voltages of 12V and 5V are generated for each battery pack control module.

Further, the 12-5DC/DC module C and 12-5DC/DC module D are connected to the vehicle battery through wires, and under the action of the control signal generated by the logic circuit, the main control module generates two types of 5V voltages.

Further, the logic circuit generates logic control signals CRL5, CRL6, CRL7 and CRL8 under the action of the main controller module control signals CRL2, CRL3 and CRL4, wherein CRL5 and CRL6 are respectively used for the main controller module and the connected The wake-up function of the data memory, CRL7 and CRL8 are respectively used for logic control of two kinds of 5V voltages.

Description of drawings

The accompanying drawings are used to provide a further understanding of the utility model, and constitute a part of the description, and are used to explain the utility model together with the embodiments of the utility model, and do not constitute a limitation to the utility model.

Fig. 1 is a block diagram of the overall structure of the series lithium battery management system for electric vehicles proposed by the utility model.

Fig. 2 is a structural block diagram of the battery pack control module proposed by the utility model.

Fig. 3 is a structural block diagram of the power supply control module proposed by the utility model.

Fig. 4 is a flow chart of the main body of the battery management system proposed by the utility model.

Detailed ways

The preferred embodiments of the present utility model are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described here are only used to illustrate and explain the present utility model, and are not intended to limit the present utility model.

Figure 1 is a block diagram of the overall structure of the series lithium battery management system for electric vehicles, which includes a main controller module, 8 battery pack control modules, a battery voltage detection module, a battery current detection module, a data storage module, a temperature control module, and a display module , alarm module, power module and power control module.

When the electric vehicle is ignited, the main controller module switches to the battery pack through the power control module and turns on the power module to supply power to each battery pack control module; through the battery voltage detection module and battery current detection module, the entire battery pack is collected according to a certain sampling period If the battery pack voltage drops below the rated voltage, an audible and visual alarm will be issued through the alarm module, and relevant information will be displayed on the LCD screen of the display module at the same time; at the same time, the main controller module communicates with the 8 A battery pack control module performs real-time communication, receives the terminal voltage, discharge current, and temperature signal of each single battery, and stores all the received data in the data storage module, performs real-time SOC estimation, and balances charge and discharge for the battery. The module provides the basis for control, and the controller performs battery matching analysis and battery service life estimation based on these three types of historical data; when the temperature value of each single battery received through the CAN bus exceeds the set value, the main controller module will trigger the temperature The control module starts the air-cooling equipment; if the voltage or discharge current value of each single battery received through the CAN bus is abnormal, an audible and visual alarm will be issued through the alarm module, and relevant information will be displayed on the LCD screen, and all abnormal information codes will be saved in the data memory block.

When the electric vehicle is turned off, the main controller module determines whether to charge the single battery whose capacity is less than the set value according to the stored historical data. If charging is required, switch to the on-board battery through the power supply control module to supply power to each battery pack control module and carry out small-scale balanced charging, and store information such as voltage, current, and charging time; The battery pack controls the power supply of the module, and the main controller module enters the timing wake-up mode.

Figure 2 is a structural block diagram of the battery pack control module, which includes a battery pack controller, a sampling module, a switching module, a charging and discharging module, a single battery temperature detection module, a single battery voltage detection module, a battery pack current detection module and a communication module.

The main controller module powers up the battery pack control module. After the system is initialized, the temperature, voltage, and charge and discharge current of 11 single cells are measured in real time through the single cell temperature detection module, single cell voltage detection module, and battery pack current detection module. value, the battery pack controller then collects the measured value in time-sharing through the sampling module, and sends it to the main controller module in the form of CAN bus through the communication module; after the battery pack controller receives the charge and discharge command from the main controller module, Select the single battery that needs to be charged and discharged by controlling the relay matrix in the switching module, and turn on the function of the charging and discharging module to perform balanced charging and discharging for the single battery.

Figure 3 is a structural block diagram of the power control module, including the power switching module, logic circuit, 12-12DC/DC module A, 12-12DC/DC module B, 12-5C/DC module A, 12-5DC/DC module B, 12-5DC/DC module C, 12-5DC/DC module D.

The power supply of the battery management system comes from the vehicle battery or battery pack, and the power control module realizes the function of selecting or switching power supply for the main controller module and each battery pack control module. After the electric vehicle is ignited, the main controller module triggers the power switching module through the control signal CRL1, selects the battery pack power supply and provides 12-12DC/DC module A, 12-12DC/DC module B, 12-5C for each battery pack control module /DC module A, 12-5DC/DC module B four power supplies, of which 12-12DC/DC module A, 12-12DC/DC module B provide power for the sampling module and relay respectively, 12-5C/DC module A, 12 The -5DC/DC module provides 5V reference voltage and working voltage for the battery pack control module respectively; after the electric vehicle is turned off, if there is no need to charge each part of the single cells in a balanced manner, the main controller module turns off each battery pack control module through CRL1 If balanced charging is required, the power switching module selects the battery to provide power for each battery pack control module; the vehicle battery always provides two types of 5V power for the main controller module 12-5DC/DC module C, 12-5DC/DC Module D: After the electric vehicle is turned off and the single battery does not need to be balanced for charging and discharging, the main controller module enters the timing wake-up mode, and the logic circuit generates logic control under the action of the control signals CRL2, CRL3 and CRL4 of the main controller module. Signals CRL5, CRL6, CRL7 and CRL8, wherein CRL5 and CRL6 are respectively used for the wake-up function of the main controller module and the data storage module connected to it, and CRL7 and CRL8 are used for logic control of two types of 5V voltages respectively.

Fig. 4 is the main flow chart of the management method of the battery management system proposed by the utility model, which specifically includes the following steps:

S1: Initialize after the system is powered on;

S2: First judge whether the battery is in the charging state, if it starts to charge, then execute S3, if it is not in the charging state, then execute S4;

S3: Start to record the charging time, charging current, and voltage across the battery of all single batteries, and accumulate the charging times and total charging time of the battery, and provide the data to S13 at the same time;

S4: Determine whether the battery is in the discharge state. If it starts to discharge, execute S5. If it is not in the discharge state, return to S2;

S5: Start recording the discharge time, discharge current, and voltage across the battery of all single batteries, and accumulate the discharge times and total discharge time of the battery, and provide the data to S13 at the same time;

S6: Call the battery capacity estimation subroutine to estimate the nuclear power state SOC _i of each battery;

S7: Calculate the average capacity of all batteries and the difference of each cell from the average capacity , and provide the data to S13 at the same time;

S8: Find and record the 5 largest capacity differences among all batteries ;

S9: Use the latest 5 capacity differences Compare with the 5 largest in history;

S10: Through comparison, judge whether the capacity difference of the same battery belongs to the 5 largest differences in 5 consecutive battery charge and discharge, if yes, enter S11, and provide the data to S13 at the same time; if not, return to S8;

S11: Call the battery matching degree subroutine, calculate the matching degree of the battery used, and find out the unmatched single battery;

S12: Call the display subroutine to display the matching result or battery life estimation result on the LCD screen;

S13: Call the battery life estimation subroutine to predict the battery life.

In summary, the management system of series lithium batteries for electric vehicles in the embodiment of the present invention has a master-slave structure based on the control system of the Freescale microcontroller. On the basis of accurate measurement of the voltage, current and temperature of the single battery Realize a more accurate estimation of the capacity of the single battery, and can realize the balanced charge and discharge control of the battery; on the basis of accurate measurement based on hardware, the software system can calculate the matching degree of the single battery in the entire battery pack and estimate the service life of the battery.

Finally, it should be noted that: the above is only a preferred embodiment of the utility model, and is not intended to limit the utility model, although the utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art , it is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims (8)

1. a serial lithium battery management system used for electric vehicle, comprises main controller module, it is characterized in that:

Described lithium battery management system is also provided with the battery pack control module, battery voltage sensing module, battery current detection module, data-storing module, temperature control module, display module, alarm module, power module and the energy supply control module that are electrically connected with main controller module;

Main controller module is connected battery pack by battery voltage sensing module with battery current detection module, and main controller module is by gathering magnitude of voltage and the discharging current of whole battery pack by battery voltage sensing module and battery current detection module;

Main controller module and battery pack control module are interconnected by function CAN communication pin, main controller module and display module are interconnected by functional pin, main controller module and temperature control module are interconnected by functional pin, main controller module and alarm module are interconnected by functional pin, main controller module and power module are interconnected by functional pin, main controller module and energy supply control module are interconnected by functional pin, energy supply control module is interconnected by functional pin with power module again, energy supply control module realizes energy supply control module under dead ship condition by logical circuit and has uninterrupted arousal function to main controller module, and be that battery pack control module is selected or opens by diverter switch, close power supply, energy supply control module controls switching and the open and close of power module.

2. one according to claim 1 serial lithium battery management system used for electric vehicle, is characterized in that: described battery pack control module is made up of battery controller, sampling module, handover module, charge-discharge modules, cell temperature detecting module, monomer battery voltage detection module, battery pack current detection module, communication module and supply module.

3. one according to claim 2 serial lithium battery management system used for electric vehicle, is characterized in that: described battery controller is interconnected by functional pin and sampling module with cell temperature detecting module, monomer battery voltage detection module and battery pack current detection module respectively; Battery controller and supply module are interconnected by pin, for battery controller provides power supply; Battery controller and charge-discharge modules are interconnected by pin, carry out controlling functions to cell charge and discharge process; Battery controller and communication module are interconnected by pin, and battery pack control module and main controller module are by CAN swap data.

4. one according to claim 3 serial lithium battery management system used for electric vehicle, is characterized in that: described handover module, monomer battery voltage detection module and charge-discharge modules are interconnected by wire with the both positive and negative polarity of each cell of this group respectively.

5. the serial lithium battery management system used for electric vehicle of the one according to the arbitrary claim of Claims 1 to 4, it is characterized in that: described battery pack is composed in series by the cell of equal number, battery pack is connected in series composition power brick mutually as power supply used for electric vehicle.

6. one according to claim 5 serial lithium battery management system used for electric vehicle, is characterized in that: described energy supply control module is made up of electrical source exchange module, logical circuit, 12-12DC/DC module, 12-5C/DC module.

7. one according to claim 6 serial lithium battery management system used for electric vehicle, is characterized in that: described 12-12DC/DC module is made up of 12-12DC/DC modules A, 12-12DC/DC module B; Described 12-5C/DC modules A 2-5C/DC modules A, 12-5DC/DC module B, 12-5DC/DC module C, 12-5DC/DC module D form.

8. one according to claim 7 serial lithium battery management system used for electric vehicle, it is characterized in that: electrical source exchange module is connected with Vehicular accumulator cell, power brick and 12-12DC/DC modules A, 12-12DC/DC module B, 12-5C/DC modules A, 12-5DC/DC module B respectively, and for each battery pack control module respectively produces the voltage of two class 12V and 5V under the effect of main controller module control signal CRL1; 12-5DC/DC module C, 12-5DC/DC module D are connected by wire with Vehicular accumulator cell, and for main control module produces the voltage of two class 5V under the control signal effect of logical circuit generation; Logical circuit is under the effect of main controller module control signal CRL2, CRL3 and CRL4, produce logic control signal CRL5, CRL6, CRL7 and CRL8, wherein CRL5, CRL6 are respectively used to the arousal function of main controller module and coupled data memory, CRL7 and CRL8 is respectively used to the logic control of two class 5V voltages.