Active cell balancing of Li-Ion batteries using single capacitor and single LC series resonant circuit

Ferdous S Azad,Abidur Rahman,Istiak Ahmed,A K M Ahasan Habib

doi:10.11591/eei.v9i4.1944

Abstract

In this paper a novel single series resonant tank and capacitor converter based voltage balancing circuit for series supercapacitor string and battery cells string is presented. It recognizes the balancing circuit which recovered the maximum energy and zero voltage gap between cells in a series supercapacitor system or battery system. This balancing circuit not only inherits the improvement of conventional single series resonant converter based balancing system, but also recovers the drawback of switching loss, conduction loss and voltage gap between cell strings. All MOSFET switches are controlled by a pair of complementary PWM signals. Also the resonant tank and parallel capacitor operate between the two mode of charging and discharging. This voltage balancing circuit has shown promising result to be used in battery management system.

Highlights

Electric vehicles (EV) has become popular in last few years
The DC to DC active voltage balancing circuit is simulated in MATLAB SIMULINK-2016a
Supercapacitors are used as an energy storage cells for this topology

Summary

INTRODUCTION

Electric vehicles (EV) has become popular in last few years. In the transportation sector EVs are suitable alternative to gas or diesel engine vehicles because of ecological and economical issues [1]. In EV, electricity is used to drive the motor without emitting any CO, CO2, nitrogen oxides, sulphur dioxide For these reasons EV is called zero-carbon emission vehicle which will solve the energy and environmental issues [2]. The rechargeable batteries or supercapacitors are electrochemical vessel, for that reason after some charging and discharging cycles their physical characteristics will change Due to their internal resistance, in terms of capacity among the battery cells are slight different which causes imbalance in the cell voltage during charging and discharging time. A BMS can monitor the individual cell status on charging or discharging time, the charge balancing system could save the Li-ion cell from over-charging and over-discharging hazard and increase the performance of the rechargeable battery or supercapacitors to supply power effectively in EV [8,9].

PROPOSED VOLTAGE BALANCING CIRCUIT

PRINCIPLE OF VOLTAGE BALANCING SYSTEM:

Operational mode I

Operational mode II

RESULTS AND DISCUSSION

CONCLUSION