Master's Thesis from the year 2013 in the subject Electrotechnology,
grade: 2.3, RWTH Aachen University (Institut für Stromrichtertechnik und
Elektrische Antriebe (ISEA)), language: English, abstract: The accurate
state of charge (SOC) is required for the battery for hybrid electric
vehicles (HEV). Because HEV batteries, a widely fluctuating current
profile; partial recharging phases (regenerative braking); inadequate
lifetimes to date; expanding market and strong competition from other
battery technologies is a major drawback in this application. Though as
lead acid batteries are improved as well, they are widely used for micro
hybrid vehicles, and the types of lead acid batteries, which are used in
micro hybrid cars are quite similar to starter batteries. The motivation
of this thesis work is to eliminate the drawback and determine the SoC
of the energy storage system (lead acid battery) in the HEV. Because the
conventional SoC determination method (e.g. coulomb counting, chemical
method, voltage method etc) cannot measure the SoC correctly. In this
thesis, I studied, analysed and compared different published research
works and proposed a new approach by using electromotive force (EMF) to
calculate SoC, which was successfully developed and validated.
