• NEW! Protection Circuit Module For Li-ion Battery Pack

    NEW! Protection Circuit Module For Li-ion Battery Pack

    Regular Price: 45.36$
    Latest Price:    29.99$

    Protection Circuit Module For Li-ion Battery Pack

    Abstract

    The utility model discloses a general-purpose lithium battery protection system, which comprises a lithium battery pack respectively connected to a load and a charger, wherein the protection system is a single-chip computer to collect battery information of a lithium battery pack, and the single-chip microcomputer is charged and discharged. The channel control circuit realizes the charge and discharges conversion of the lithium battery pack; the charging current detection module and the discharge current detection module respectively collect the voltage values in the loop and transmit them to the single chip microcomputer. Due to the above structure, the present invention can effectively protect all types of lithium batteries currently on the market.

    Description

    Protection Circuit Module For Li-ion Battery Pack

    Technical field

    [0001] The utility model relates to the field of application of a lithium battery, in particular to a universal lithium battery protection system.

    Background technique

    [0002] In the new energy system, batteries are an indispensable part of them. In recent years, lithium batteries have been widely used due to their high energy density, long service life, and high single-cell voltage. However, lithium batteries may cause damage to the battery life due to heating, overcharge/over-discharge current, vibration, extrusion, etc., and may even cause a fire, explosion, etc., so the powerful lithium battery pack needs to be protected.

    [0003] At present, the lithium battery protection scheme mainly includes: Seiko S8261 for single-cell battery, Lingte bq77910, bump 0Z8920, AD company AD7280A and other chips mainly for 8_16 string lithium battery pack, but their protection threshold voltage is mostly lithium iron phosphate Set with lithium manganate. At present, there is no solution that can effectively protect new lithium batteries such as lithium titanate batteries.

    [0004] In view of the above problems, a universal protection system is provided, and the effective protection of all types of lithium batteries currently on the market is a problem that needs to be solved in the prior art.

    Utility model content

    [0005] The technical problem to be solved by the present invention is to provide a universal lithium battery protection system for the purpose of effectively protecting all types of lithium batteries currently on the market.

    [0006] In order to achieve the above object, the technical solution of the present invention is a general-purpose lithium battery protection system, including a lithium battery pack respectively connected to a load and a charger, wherein the protection system is a single-chip microcomputer for collecting lithium batteries. The battery information of the group, the single-chip microcomputer realizes the charge-discharge conversion of the lithium battery pack through the main channel control circuit of charging and discharging; the charging current detecting module and the discharging current detecting module respectively collect the voltage values in the loop and transmit to the single-chip microcomputer.

    [0007] The single-chip microcomputer sets two threshold voltages of overcharge voltage OV and release voltage UV when charging the lithium battery pack, and when the battery is charged to the overcharge voltage OV, the single chip disconnects the charging circuit of the lithium battery pack, when the lithium battery pack When the voltage drops back to UV, the MCU allows the charger to restart the charging function; the lithium battery pack has two threshold voltages of over-discharge voltage OD and over-discharge voltage UVD when discharging, when the lithium battery pack discharge reaches the over-discharge voltage OD The single-chip microcomputer prohibits the discharge of the lithium battery pack. When the voltage of the lithium battery pack rises to the UVD, the single-chip microcomputer can restart the discharge function.

    [0008] The model of the single-chip microcomputer is STM8L1514K.

    [0009] The charger and the load respectively feedback the working information to the single-chip microcomputer through the under-voltage wake-up and the off-charger detection circuit and the off-load detection circuit.

    [0010] The single-chip microcomputer is connected to a charging circuit of a lithium battery pack through a pre-charging circuit.

    [0011] The protection system is provided with a short circuit protection module and a discharge over the current determination module.

    [0012] The single chip is connected with a temperature detecting module and a system communication module.

    [0013] The lithium battery pack connection system power generation module supplies power to the entire protection system.

    [0014] The protection system is provided with a weak electric lock judging module.

    [0015] Protection Circuit Module For Li-ion Battery Pack is sent to the single-chip microcomputer through the single-cell battery voltage differential circuit module to complete the difference of the single-cell voltage, and the single-chip built-in a/d conversion module performs conversion; the single-chip microcomputer accesses the lithium battery pack through the equalization control module.

    [0016] A general-purpose lithium battery protection system, by adopting the above structure, the utility model can effectively protect all types of lithium batteries currently on the market. It can be adapted to the needs of current-voltage threshold lithium battery protection and has the advantages of function and cutting optimization (please describe the advantages of the utility model)

    DRAWINGS

    [0017] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments;

    1 is a structural block diagram of a general-purpose lithium battery protection system according to the present invention;

    2 is a circuit diagram of a system power generation module in a universal lithium battery protection system according to the present invention;

    3 is a circuit diagram of an A/D conversion module of a single-chip microcomputer in a general-purpose lithium battery protection system according to the present invention;

    4 is a circuit diagram of a discharge channel in a universal lithium battery protection system according to the present invention;

    [0022] FIG. 5 is a circuit diagram of a charging channel in a universal lithium battery protection system according to the present invention;

    [0023] In FIG. 1, 1, a lithium battery pack; 2, a single-chip microcomputer; 3, a charger; 4, a load; 5, a single-cell battery voltage differential circuit;

    6, charge and discharge main channel control circuit; 7, undervoltage wake-up and disconnect charger detection circuit; 8, broken load detection circuit; 9, charging current detection module; 10, discharge current detection module; 11, pre-charge circuit; , discharge overcurrent judgment module; 13, short circuit protection module; 14, temperature detection module; 15, system power generation module; 16, system communication module; 17, weak electric lock judgment module; 18, equalization control module.

    Detailed ways

    [0024] As shown in FIG. 1, the utility model comprises a lithium battery pack 1 respectively connected to a load 4 and a charger 3, wherein the single-chip microcomputer 2 in the protection system collects battery information of the lithium battery pack I, and the single-chip microcomputer 2 passes through charging and discharging main channel control circuit. 6 Realizing the charge and discharge conversion of the lithium battery pack I; the charging current detecting module 9 and the discharging current detecting module 10 respectively collect the voltage values in the loop and transmit them to the single chip microcomputer 2. The charger 3 and the load 4 feedback the operation information to the single chip microcomputer 2 through the undervoltage wakeup and off charger detecting circuit 7, and the offload detecting circuit 8, respectively. The single chip microcomputer 2 is connected to the charging circuit of the lithium battery pack 1 through the precharge circuit 11. The single chip microcomputer 2 is connected to the lithium battery pack 1 through the equalization control module 18.

    [0025] The utility model is provided with a short circuit protection module 13 and a discharge overcurrent determination module 12. The single chip microcomputer 2 is connected with a temperature detecting module 14 and a system communication module 16. The lithium battery pack I connection system power generation module 15 supplies power to the entire protection system. A weak electric lock judging module 17 is provided in the protection system.

    Specifically, the present invention adopts a low-end control mode. In Fig. 1, B+ is the positive electrode of the lithium battery pack 1. When the battery is in a discharged state, current flows from the internal flow of the battery through B+ to the D- through the load, and from the D- through the discharge control channel to the negative terminal of the battery. When the battery is in the charging state, the current flows from the positive pole of the charger to the battery through B+, and then flows out from the negative pole of the battery, and flows to the C-, C-, and finally to the negative pole of the charger through the charging control channel.

    [0027] The utility model takes the STM8L1514K single-chip microcomputer 2 as the control core, and the single-chip microcomputer has the characteristics of low power consumption and rich peripheral resources and is very suitable as a relatively complicated embedded system controller. After the single-cell battery is connected in series, the positive electrode potential of each battery is different. The single-cell battery voltage differential circuit 5 is sent to the single-chip microcomputer 2 after completing the difference of the battery cell voltage and is converted by the built-in A/D conversion module of the single-chip microcomputer 2 to obtain the lithium battery pack. I all battery information. According to the characteristics of the lithium battery, the lithium battery has two threshold voltages when charging. First, the overcharge voltage is 0V. When the battery charge reaches OV, the protection system must prohibit charging. Second, the overcharge release voltage UV. When the battery is disabled, the battery voltage will drop due to the characteristics of the lithium battery. Only the voltage falls back to The battery protection system can restart the charging function when UV. Lithium batteries also have two threshold voltages when discharging. One is the over-discharge voltage 0D. When the battery discharge reaches OD, the protection system must prohibit its discharge. The second is the over-discharge release voltage UVD. Due to the characteristics of the lithium battery, the battery voltage will rebound after its ban, only its voltage rises to UVD. The battery protection system can restart the discharge function. Since the charging and discharging current directions are different in magnitude, in order to ensure the sampling accuracy, the utility model uses two independent modules for detection. When the lithium battery charge and discharge current is too large, it will also damage the battery itself. The utility model is designed with an overcurrent protection OC function. The temperature of the lithium battery is also extremely important for the battery. The high temperature not only affects the charge and discharge characteristics of the battery but also causes the battery to explode and cause a safety accident. Therefore, the utility model is connected with the temperature detecting module 14 and has an over temperature protection function OT. And over temperature protection release function UT.

    [0028] The entire lithium battery system must be protected from short circuit operation. The lithium battery has three working states: charging, discharging, and standing. The protection system needs to know the conditions in which the state of the lithium battery and the various working states are mutually transformed. The switching condition of the lithium battery rest state and the working state is provided by the weak electric lock judging module 17. When the battery is under voltage, it must enter the low power mode and then unlocked by connecting the charger. When the battery voltage is too low, it must first be charged with a small current until the voltage is high enough to use normal current charging to protect the battery. The system has designed two pre-charging circuits, charging and discharging the main channel. The communication module is designed to modify the corresponding parameters and upload the battery real-time parameters to other devices according to different types of batteries. The power supply for the entire solution comes from the battery itself that needs to be protected, so the power supply of the solution is also specially designed.

    [0029] The power supply of the utility model all comes from the lithium battery pack 1 that needs to be protected, and can be divided into four parts: the power supply of the single-chip microcomputer 2, the power supply of the ordinary peripheral, the power supply of the differential loop, and the reference potential of the A/D conversion. As shown in Figure 2, BAT+ and ground are taken from both ends of lithium battery pack I, a 10.6V regulated power supply is generated by Ql, Q2, Fl, then 3.1V regulated power supply is generated by HT7133-1, and finally -the 3.1V potential is generated by ICL600. In order to minimize system power consumption when the battery is in a resting state, the system power generation module 15 controls 10.6V and 3.1V using MOSFETs Q3, Q4, as shown in the figure BMU_P0WER and VCC0 Q3, Q4 control signals BMU_P0WER_SW, P0WER_SW Provided by the microcontroller 2. The -3.1V potential is used for differential op amps. In order to improve the accuracy of AD sampling, a reference potential AD_REF is designed using a three-terminal regulator AZ432, as shown in Figure 3.

    [0030] When the battery is discharged, current flows from the positive electrode of the battery through the load to D-, and then flows through the channel to the negative electrode of the battery (ie, ground), as shown in FIG. Two MOSFETs FET1 and FET2 are used to improve the current capability of the main channel, and the control is controlled by the control signal Discharge_MOSFET_Ctrl issued by the single chip microcomputer 2. R06 is a current sampling resistor, generally taking Im Ω. The resistor R1 and the diode D1 constitute a control circuit of the transistor Q1. As shown in the figure, one end of the battery is connected to the positive electrode B+ of the battery, and the other end is connected to the sampling resistor R06. When the discharge current of the main channel is below 50A, the voltage drop on R06 is small, diode D1 is in the on state, and Dl selects the tube with the conduction voltage drop of 0.3V. The transistor Q1 is in a non-conducting state, and the three-pin potential of Q1 is the same as the three-pin potential of Q2 (Discharge_Short_Current_Protect). When the discharge channel occurs

    [0031] When a short circuit, the current will be very large, the Current_Res_Monitor potential will rise, the voltage difference between Dl will disappear, Dl will no longer conduct, the transistor Ql will be turned on, and the Discharge_Short_Current_Protect potential will be pulled low. Further, the Discharge_Mosfet_Monitor potential is pulled low, the main channel FET1 and FET2 are turned off, and the battery pack stops discharging to provide short-circuit protection. Once FET1 and FET2 are turned off, the D-potential is the same as B+. At this time, transistor Q2 is turned on, Discharge, Short_Current_Protect potential is locked low, and FET1>FET2 remains off, which has nothing to do with Discharge-M0SFET_Ctrl level. The function of short-circuit protection and locking to discharge. The D-end is separated from the load, Q2 has turned off again, and the discharge main channel can be unlocked, that is, the load-breaking unlock function.

    [0032] As shown in FIG. 5, the charging main channel current flows from the charger into the battery B+ and flows out from the negative electrode of the lithium battery to the negative terminal of the charger through the charging main channel. The present invention has been exemplarily described with reference to the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited by the above-mentioned manners, as long as various improvements made by the technical solutions of the present invention are adopted, or directly applied without improvement. In other cases, it is within the scope of protection of the present invention.

    No comments

    Welcome to visit my blog. Thanks for your comment. We will replay a few minute😊😊

    Post Top Ad

    UK Web Hosting Services