The composition of lithium iron phosphate battery and the method of BMS fault analysis
11 Jun 2021 - lithium-ion battery lithium iron phosphate batteries.
Our lives are constantly changing with global diversity, including all kinds of electronic products that we're exposed to, and you're not familiar with some of the components of these products, such as lithium iron phosphate batteries.
In recent years, large capacity without secondary pollution of the battery has come out one after another, the price of performance is also getting higher and higher, always understand the attributes of the battery, which requires a battery management system to achieve.However, it's not just a question of whether a lithium-ion iron phosphate battery pack needs BMS.Lithium-ion battery system is huge, so it is necessary to supervise and optimize the management system of lithium-ion iron phosphate battery to maintain its safety, durability and power performance.
Battery management system BMS, which involves microcomputer technology and detection technology, dynamically monitor the running state of the battery unit and battery pack, can accurately calculate the remaining power of the battery, charge and discharge protection of the battery, make it in the best working state, reduce the operating cost, improve the service life.In this paper, a new management system for lithium-ion iron phosphate battery is designed and implemented based on some advanced achievements at home and abroad.
Iron phosphate lithium ion battery BMS management system is not as optional as some battery production companies said, but must have, but also throughout the application of lithium ion battery pack.BMS lithium-ion battery management system has been studied at home and abroad, and began to be applied in many fields, has been able to meet the needs of some markets, the application of lithium-ion battery has put forward higher requirements for the battery management system, to ensure the safety of power lithium-ion battery pack, is the primary task of lithium-ion battery management system。
The composition of lithium ion iron phosphate battery pack
(1) Battery module
For example, a 50Ah lithium-ion iron phosphate battery requires 16 cells, each 3.2V.The height of the battery is 4U, which can be embedded into the machine roomless cabinet. A single battery pack can be used in parallel to form a battery pack with a larger capacity。
(2) Battery Management System (BMS)
BMS is mainly used to manage the charge and discharge process of batteries, improve the service life of batteries, and provide users with relevant information circuit systems.BMS generally consists of monitoring, protection circuit, electrical, communication interface, thermal management device and other parts.Its important functions include intelligent charge management, battery balance management, intelligent intermittent charge and discharge management, thermal system management, communication management, etc.
Lithium ion Iron phosphate battery pack with BMS
The ideal lithium-powered lithium-ion battery has a high degree of consistency in performance.As long as the battery is overcharged or overdischarged during use, there is no safety problem.The actual situation is that the quality of the mobile phone battery is fully up to the standard when it is delivered, but it explodes in the process of use.There have also been reports of fires, explosions in laptop battery packs and product recalls.
Lithium-ion iron phosphate batteries have safety problems from the beginning to the end of life and recovery.Even if the factory is fully in line with international safety standards, it will evolve from a safe state to an unsafe state during use.The performance of a single section of lithium iron phosphate battery with good quality gradually decreases to reach the service life.An inferior battery will gradually undergo various abnormal degradation
and decay in the course of use, and enter a worrisome unsafe state.It's a process of cumulative change.
BMS is not optional, as some battery companies claim, but a must, and it runs through the use of lithium-ion iron phosphate batteries.BMS has been studied at home and abroad and has been applied in many fields.It has been able to meet the needs of some markets.The application of lithium-ion battery puts forward higher requirements for battery management system to ensure the safety of lithium-ion battery pack.This is the primary task of power lithium-ion iron phosphate battery management system.
BMS fault analysis method for lithium iron phosphate battery pack
● Fault repetition method
BMS vehicles with lithium-ion iron phosphate battery packs have different faults under different conditions.Where conditions permit, the fault should be reproduced under the same conditions as far as possible and the problem points should be identified.
When similar interference phenomenon occurs in the system, each part of the system should be removed one by one to determine the part that affects the system.
●Low substitution method
When the temperature, voltage and control of a module are abnormal, change the position of the module with the same number of strings to diagnose the module problem or the wiring harness problem.
Lithium-ion iron phosphate batteries will power the entire vehicle.It is wrapped in a metal case to form the body of the battery pack.The module structure design realizes the integration of the module, including the cooling hardware of the module.The quality of cooling system design is the premise of good management of BMS.