Development of battery management system for cell monitoring and protection

Abstract

Battery has an important role as energy storage in electricity system utilization such as in electric vehicle and in smart microgrid system. Battery Management System (BMS) is needed to treat the dynamics of energy storage process in the battery in order to improve the performance and extend the life time of battery. In this paper, BMS cell monitoring and protection has been designed and tested for Lithium Ferro Phosphate (LFP) battery cells. The BMS cell monitoring function has been able to measure the battery parameters such as the voltage and current dynamics of each cell. The data taken from the BMS cell monitoring experiment is used to estimate the state of charge (SOC) of battery which is based on coulomb counting with coulomb efficiency ratios. The BMS cell monitoring function has successfully demonstrated the presence of unbalanced cell voltages during both processes of charging and discharging as well. From the analysis, the existence of capacity and energy fades was also investigated for every discharging and charging cycles. Based on the BMS cell protection experiment results, overcharged and over discharged protections have successfully been demonstrated for the battery cells. The charging process is disabled when the voltage of the corresponding battery cell exceeds its high limit (HLIM) at 3.65V, and the battery will be available for charging when all of the cell voltages are below their boundary limits (CAVL) at 3.3V. The discharging process will be disabled when the battery cell voltage is lower than the corresponding low limit (LLIM) at 2.5 V. The battery will be available again when all battery cell voltages are above their discharge available (DAVL) voltage at 2.8V. The proposed BMS cell monitoring and protection has shown its function as a data acquisition system, safety protection, ability to determine and predict the state of charge of the battery, and ability to control the battery charging and discharging.A BMS which flexible enough to protect different types of batteries and can provide all the safety features, has been a recent topic of development and research in electric vehicle and alternative energy systems [3]. As described in [2], a comprehensive BMS should include functions for data acquisition, safety protection, ability to determine and predict the state of the battery, ability to control battery charging and discharging, cell balancing, thermal management, delivery of battery status and the authentication to a user interface, communication with all BMS components and the most important thing is to prolong battery life.

Design and Implementation of Battery Management System for Electric Bicycle

“…This system will cut off the relay that measure the voltage between positive and negative terminal of the battery if it detects overcharge, over discharge, overload and short circuit [6]. Place the figure as close as possible after the point where it is first referenced in the text.…”

Performance Analysis of Energy Storage in Smart Microgrid Based on Historical Data of Individual Battery Temperature and Voltage Changes

“…The BMS will examine the operational parameters of the battery (e.g. voltage, current, and temperature) to estimate the battery state and control the charging and discharging processes [16] while maintaining safe and optimal operation of each battery [14]. BESS generate heat during rapid charge and discharge cycles at high current levels.…”

Design and Implementation of Software Calibrated Lead-Acid Monitoring System for Electric Motorcycle

“…The common scheme of cell voltage monitoring include: BMS chip monitoring [1], switching polling monitoring [2], master-slave multi module monitoring [3,6]. All schemes mentioned above can guarantee high monitoring accuracy.…”