Adaptive Neuro-Fuzzy Control Circuit for Cell Equalization in Battery Management System

Abstract

In battery system, Li-ion cells are more and more replacing the traditional acid batteries, due to its lightweight and higher energy density. They are widely used in products such as the portable consumer electronic devices. Each lithium-ion battery cell can produce voltage from 1.5V to 4.5V. However, applications such as electronic vehicles (EV) require much higher voltages. Such high voltage can be achieved through serially connected cells. Generally, an EV battery pack consists of hundreds of connected individual cells. However, the imbalance between cells is a severe problem in these high voltage battery systems. These phenomena cause premature failures of the cells, and possible damage to the cells. Therefore, in serially connected battery string, balancing voltages between the battery cells is essential for cell protection and prolongation of the battery life. In this thesis, all the perspectives about battery equalization from basic fundamentals to critical analysis are presented. In addition, the proposed optimal control method for battery management system is elaborated to enhance the energy ecency and equalizing time performances. . . .