Low Voltage Battery Management System with Internal Adaptive Charger and Fuzzy Logic Controller

Abstract

Lithium ion (Li-Ion) and lithium polymer (Li-Po) batteries need to be used within certain voltage/current limits. Failure to observe these limits may result in damage to the battery. In this work, we propose a low voltage battery management system (LV-BMS) that balances the processes of the battery cells in the battery pack and the activating-deactivating of cells by guaranteeing that the operation is within these limits. The system operates autonomously and provides energy from the internal battery. It has a modular structure and the software is designed to control the charging and discharging of eight battery cells at most. A STM32F103 microcontroller is used for system control. The fuzzy logic controller (FLC) is used to set the discharge voltage limit to prevent damage to the battery cells, shorten the settlement time and create a specialized design for charge control. The proposed structure enables solar panel or power supplies with different voltage values between 5 V and 8 V to be used for charging. The experimental results show there was a 42% increase in usage time and the voltage difference between the batteries was limited to a maximum of 65 mV. Moreover, the charge current settles at about 20 ms, which is a much faster response when compared to a PID controller.

Recent Advancements in Battery Management System for Li‐Ion Batteries of Electric Vehicles: Future Role of Digital Twin, Cyber‐Physical Systems, Battery Swapping Technology, and Nondestructive Testing

“…The operating voltage and operating currents are the two major factors which affects the life, and performance of the battery. [ 35–44 ] It is advised that both the operating voltage and operating current should be kept within the safe operating area (SOA). Any operation beyond SOA may result in the permanent failure of the battery.…”

“…In this regard, Goksu et al [ 37 ] developed a voltage‐controlled BMS using a microcontroller. They investigated that the fuzzy logic controller and the charge controller compares the battery voltage level to the desired value and accordingly sends the data to the user, which includes the steps such as activate charging, deactivate charging, and set charge.…”

“…The estimation of SOH of the battery is one of the decisive factors in the performance of the EV. [ 35–50 ] The SOH of the battery is defined as the ratio of the present capacity to the capacity of the battery when it is just manufactured. It is observed that if SOH falls below 80% of its initial value, the battery is said to be unfit for use.…”

A novel battery management scheme for critical loads

“…A BMS for four Li-ion cells was constructed by utilizing STM32F103C8 and PIC18F4520 microcontrollers as master and slave controllers to monitor and regulate cell voltages, currents, and temperatures was discussed in Ref. [19]. A battery thermal management system (BTMS) with different cooling techniques are proposed in Ref.…”