Browse Publications Technical Papers 2018-01-0443
2018-04-03

Battery Impedance Measurement with Step Current of Different Amplitude under Temperature and State of Charge Control 2018-01-0443

Electrochemical Impedance Spectroscopy (EIS) is often applied to analyze and describe the battery internal electrochemical processes. And the methods of battery state estimation including state of health diagnosis with electrochemical impedance have attracted a wide attention. In the paper, a novel fast impedance measuring method based on wavelet transform with a step excitation current is proposed and further studied. With the method, the current generated by the electric vehicle and the responding voltage of the battery can be utilized to calculate and provide the battery impedance for the battery management system. Taking into account the varying amplitude of the current and the battery states, the battery impedance was measured with step excitation signals of different amplitude at different temperature and state of charge (SOC). Then the battery impedance was calculated with the proposed method and compared to the electrochemical impedance measured with an electrochemical workstation. It is observed that the impedance in the mid high frequency range (>10 Hz) greatly related to changes of the internal processes and properties caused by the aging process is weakly affected by the varying signal amplitude. And the effect is limited and can be neglected at high temperature (>25 °C). SOC also has little effect on the impedance in the frequency range higher than 10 Hz. It benefits the state of health diagnosis with the impedance in the frequency range. Accordingly, a state of health diagnosis method based on the impedance calculated with the wavelet transform is proposed in the end.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.

Due to current capacity constraints, printed versions of our publications - including standards, technical papers, EDGE Reports, scholarly journal articles, books, and paint chips - may experience shipping delays of up to four to six weeks. We apologize for any inconvenience.
We also recommend:
TECHNICAL PAPER

A Modular Wide Bandwidth High Performance Automotive Lithium-Ion Cell Emulator for Hardware in the Loop Application

2018-01-0431

View Details

TECHNICAL PAPER

A Novel Battery Impedance Model Considering Internal Temperature Gradient

2018-01-0436

View Details

TECHNICAL PAPER

Model-Based Evaluation of Chemistry Selection for Dual Energy Storages for 12V Advanced Start-Stop Vehicles

2016-01-1209

View Details

X