OVERVIEW OF BMS (BATTERY MANAGEMENT SYSTEM)
Semco Infratech Pvt Ltd
Lithium Battery Testing & Manufacturing Equipments Supplier ? Turnkey Automated/Semi-Automated Assembly Line
In this article, we are discussing the Importance and function of?the Battery Management system?and how it works and protect the Battery.
Introduction
BMS is an electric vehicle battery management system, which is an important link between the vehicle power battery and the electric vehicle. The BMS collects, processes, and stores important information during the operation of the battery pack in real time, exchanges information with external devices such as the vehicle controller, and solves key issues, safety, usability, ease of use, and service life in the lithium battery system. The main function is to improve the utilization rate of the battery, prevent the battery from overcharging and over-discharging, prolong the service life of the battery and monitor the status of the battery. In layman’s terms, it is a system for managing, controlling, and using battery packs.
1. What is a BMS system
1. The range of use of lithium-ion batteries is limited
For lithium-ion batteries, the ideal working range is very limited and not broad. Therefore, lithium-ion batteries must be managed during the application process, especially in the application scenario of power batteries.
2.?Security Issues
·???????Distortion
·???????Swelling
·???????Flaming on fire
·???????Explosion
overvoltage (overcharge), overcurrent, and overtemperature will bring a series of safety hazards to lithium-ion batteries.
3.?Performance Management
The external characteristics of lithium batteries are closely related to their own state (SOC/SOH/temperature) and ambient temperature.
4.?Longevity
1.????Temperature factor Environmental factor
2.????Voltage factor (SOC & ΔSOC) Voltage factor (SOC window)
3.????Current factor
High SOC and high-temperature environment will aggravate the irreversible capacity loss of the battery
5. Consistency
·???????Capacity
·???????Impedance
·???????Self-discharge rate
It is almost impossible to require all the cells in the battery pack to be completely consistent, which means that there will be inconsistent working conditions (internal resistance/heat generation / SOC range) and different aging rates between the cells, so it is necessary to Balance management.
2. What is the Main Task of BMS?
Main tasks of BMS:
BMS needs to avoid over-range abuse of power batteries and ensure the safe, reliable, efficient, and long-life operation of power batteries.
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3.?Introduction to BMS System??
1.1 BMS system architecture
A Typical BMS System Architecture
BMS System Architecture
Master-slave BMS topology
Local ECU layer
Is daisy-chained communication used?
Advantages
Disadvantages
BMS Function List & Data Sampling Requirements
BMS Function List
Estimating the remaining capacity of the Battery is the core content of the BMS and has always been a difficulty in the industry. First of all, it is an estimated value, which is calculated by the algorithm according to the battery pack voltage, current, discharge rate, temperature, and other factors. This requires your system to collect accurately enough and fast enough to ensure the final result is accurate. But this is also related to the processing speed of your main control chip, the accuracy of the AFE, the selection of the current collection scheme, and the accuracy of the temperature sensor. There are also many factors related to the overall consideration of the sampling frequency of the system. Choosing a chip with high processing speed and high precision will inevitably increase the cost. The faster the sampling frequency, the greater the system load. Therefore, under the current technical conditions, everyone refers to their own specific projects to weigh various factors.
According to the V/I/T measurement value, estimate the internal resistance capacity and then estimate the SOC and SOH. The SOC and SOH are combined to obtain the SOP available power, which is finally reflected by the user as the remaining mileage.
Common?industry?requirements?for estimation accuracy are as follows:
Data Sampling Requirements
V/I/T?Accuracy?Requirements
The provisions in the national standard QCT897 are as follows: general enterprise standards will be higher than this,
?Conclusion:
BMS helps in preventing battery failure and mitigating potential hazardous situations, which ensures that batteries function properly in the final application. It ensures that the battery operates efficiently, giving proper indications from time to time to the driver regarding the state and condition of the battery. It is the BMS that protects the battery from misuse and damage, prolongs battery life, and ensures that the battery is always ready for use. In terms of the importance and safety of the car, the BMS is definitely an underestimated part of the electric car and deserves the same attention as the battery itself.
About Semco?-?Established in 2006,?Semco Infratech?has secured itself as the number 1 lithium-ion battery assembling and testing solutions provider in the country. Settled in New Delhi, Semco gives turnkey solutions for lithium-ion battery assembling and precision testing with an emphasis on Research and development to foster imaginative, future-proof products for end users.
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