Searcharxiv⌕ Search

arXiv subjects

Costas Psychalinos

Publications and source records attributed to Costas Psychalinos.

2 recordsLinked to original sources
arXiv2023

Observation of a Pinched-Loop in a Current-Excited Inductive Circuit

In this work, we show that a pinched-loop can be observed in the voltage-current plane when a series R-L circuit is current excited. Specifically, the resistance (R) in this circuit is variable and is voltage-controlled by the voltage developed across the inductor due to the exciting current. In this context, we confirm our previous results that the pinched-loop is not a characteristic of memrsitors or memrsitive systems and that it can be observed in many other nonlinear systems. Numerical simulations, circuit simulations and experimental results validate the theory.

physics.app-ph↗
arXiv2023

Time-domain Response of Supercapacitors using their Impedance Parameters and Fourier Series Decomposition of the Excitation Signal

Supercapacitors are mostly recognized for their high power density capabilities and fast response time when compared to secondary batteries. However, computing their power in response to a given excitation using the standard formulæ of capacitors is misleading and erroneous because supercapacitors are actually non-ideal capacitive devices that cannot be characterized with a single constant capacitance. In this study we show how to estimate accurately the time-domain power and energy of supercapacitors in response to any excitation signal represented in terms of its Fourier series coefficients with the sole knowledge of the frequency-domain impedance parameters of device. The presented theory is first verified and validated with simulations conducted on an equivalent fifth-order RC circuit emulating the behavior of a fractional circuit consisting of a resistance (Rs) in series with a constant phase element (CPE) of fractional impedance ZCPE = 1/Cαsα. Then we do the same for a commercial supercapacitor modeled as an Rs-CPE circuit, and subjected to both a periodic triangular voltage waveform and a random voltage excitation. The results are conclusive and very promising for adopting the proposed procedure to estimate the power and energy performance of supercapacitors in response to real-world charging and discharging signals.

physics.app-ph↗