PROJECT TITLE :

Single-Perturbation-Cycle Online Battery Impedance Spectrum Measurement Method with Closed-Loop Control of Power Converter - 2017

ABSTRACT:

This paper presents a methodology for an online real-time electrochemical impedance spectroscopy (EIS) measurement of batteries using closed-loop management of power converter. Unlike the previously proposed technique which allows the measurement of the ac impedance for one frequency, the presented method in this paper permits for obtaining the EIS for a spectrum of frequencies by using the knowledge included during a single perturbation cycle, or a few cycles of perturbation to get a a lot of correct EIS with a very wide frequency range. This will end in faster EIS measurement for a spectrum of frequencies and beneath the identical battery operating conditions. The presented technique utilizes closed-loop control operation for the EIS measurement functionality, that allows for better control of the output voltage and for upgrading the concept to be able to realize no added perturbation ripple at the output of the system. The presented on-line real-time EIS measurement technique utilizes an influence converter with closed-loop control in order to form an output voltage step-perform perturbation at a given frequency to generate battery voltage and current responses. By applying Fourier analysis to those responses, an EIS will be obtained for a vary of frequencies equal or on top of the perturbation frequency of the step perform. Also, this paper presents a method to eliminate the added perturbation ripple when 2 or more power converters are used. The theoretical basis and experimental prototype results are provided to illustrate and validate the presented technique.