Analyze the planning plan of the low-temperature intelligent lithium battery processing system

The design summary of the low-temperature intelligent lithium battery management system analyzes the planning method of a low-temperature intelligent lithium battery processing system. The system is composed of 32 20Ah4 series and 8 parallel units. This method has basic maintenance, power measurement, power balance and fault recording functions. After testing, the system functions well and meets the planning requirements. The current battery processing system is mainly designed for the use of large-capacity battery packs and short battery life. The equipment served by the production system has high power consumption, short battery cycle, and low power consumption of the production system itself, which is not suitable for surface applications with low power consumption. For remote gas monitoring, the uniform system current is only a few milliamps, and it needs to work continuously for more than 6 months at low temperatures. In order to meet the application of this project, this paper analyzes a planning method for a low-temperature intelligent lithium battery processing system. It has functions such as basic maintenance, power metering, charging balance, and defect recording. After testing, the system functions well and meets the planning requirements. 1. The overall structure of the system The low-temperature lithium battery processing system is mainly composed of basic maintenance circuit, fuel gauge, balance circuit and secondary maintenance, as shown in Figure 1. According to the consideration of low power consumption, many low power consumption devices were selected in the planning, such as the processor adopts MSP430FG439 low power consumption single-chip microcomputer. The reference voltage is REF3325, the power consumption is extremely low, only 3.9db; the operational amplifier uses LT1495, the working current is only 1.5a; the digital potentiometer uses AD5165, the quiescent current is as low as 50nA. The power processing circuit is added to the intermittent operation circuit, the operation current is large, and the energy consumption is reduced. The additional voltage of the low-temperature battery pack is 14.8v, which consists of 4 batteries in series, and each battery pack contains 8 single cells. The normal working voltage is 2.5v~4.2v. Each collection cycle collects the voltage of each group of batteries, and the processor issues instructions to the maintenance realization circuit according to the voltage, and executes the corresponding maintenance actions. The equalization circuit is completed by a single-chip microcomputer and a transistor, instead of a dedicated equalization chip. The system records the maximum value of abnormal information such as voltage, current, temperature, battery life, and remaining power in the storage device. The processor supplies the TTL communication interface, and the on-site computer reads the log in the storage device through the TTLRS232 conversion module. In order to prevent abnormal maintenance failures such as the MCU crash during the charging process. Add a secondary maintenance circuit. If the voltage exceeds the preset value, start the secondary maintenance circuit to blow the three-terminal fuse to prevent the occurrence of failure. 2. Hardware planning 2.1 Realization of circuit maintenance The maintenance execution circuit is the execution mechanism of the maintenance action, CH is the charge control switch, and DISCH is the discharge control switch. Perform corresponding maintenance operations through the control of CH and DISCH, as shown in the circuit diagram in Figure 2. CH and DISCH are set to low level during normal operation, and M1 and M2 are turned on at the same time. When the discharge overcurrent or overdischarge status occurs, DISCH is set to high level. At this time, Q2 is disconnected, Q3 conducts, the charge of the gate capacitance of M2 is discharged rapidly, M2 is closed instantly, and the maintenance is completed. When charging overcurrent or overcharge status occurs, CH is set to high level and M1 is turned off. The MOSFET circuit chooses IRF4310, the on-resistance of the MOSFET is only 7k, and the flow rate is as high as 140. CH and DISCH are set to low level during normal operation, and M1 and M2 are turned on at the same time. When the discharge overcurrent or overdischarge status occurs, DISCH is set to high level. At this time, Q2 is disconnected, Q3 conducts, the charge of the gate capacitance of M2 is discharged rapidly, M2 is closed instantly, and the maintenance is completed. When charging overcurrent or overcharge status occurs, CH is set to high level and M1 is turned off. The MOSFET circuit chooses IRF4310, the on-resistance of the MOSFET is only 7k, and the flow rate is as high as 140. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.