On the modification of the dielectric barrier discharge electrical properties over one-hour operation using measurements without discharge

In this work, the electrical properties of a semi-industrial dielectric barrier discharge (DBD) system, characterized by a single thin dielectric, were investigated over a one-hour operation period. The discharge, generated in nitrogen, operated in the classical filamentary regime. While the discharge operated over an hour, measurements at low applied voltage, i.e. without discharge, have been introduced. The applied voltage and the charge were recorded during the non-discharge period. These measurements, analyzed using Lissajous figures and an equivalent circuit model of the setup, allowed extraction of several electrical parameters. Using basic PSIM simulations, it is first shown that the parasitic resistance (Rp) and capacitance (Cp) induce changes in the area and slope of the Lissajous figures, respectively. Those are usually used to estimate the power (Poff) and the cell capacitance (Ccell). The results demonstrated that both Poff and Ccell are increasing over one hour. Such trends are seen to be occurring whatever the electrical conditions chosen for the discharge operation. Simultaneous time resolved temperature measurements on the polymer present the same evolution than Poff and Ccell. From the strongest variation, Cp is estimated to increase from 5 pF to 64 pF, while Rp is decreasing from 14 MΩ to 3 MΩ. Such modifications are not trivial. No change in power was observed during the one-hour discharge operation. Therefore, several hypotheses are proposed to explain the observed phenomena, particularly regarding the relationship between temperature and the charge storage properties of PTFE, as discussed in recent literature.