Estimation of Secondary Electron Emission Coefficients for Dielectric Barrier Discharge Simulations

The inverter-driven motors are increasingly used in industrial and mobility applications, driving the demand for greater performance and reliability. Recent advances in power electronics have raised inverter output frequencies and slew rates, increasing the risk of discharge and insulation failure. A better understanding of discharge phenomena is thus essential. The authors are developing numerical simulations of dielectric barrier discharge (DBD) in twisted pairs of enameled wire. This study investigates the estimation and applicability of the secondary electron emission (SEE) coefficient ( $\gamma $ ) to the DBD simulations, addressing the lack of empirical data. As a result, fitting was found effective for estimating $\gamma $ from discharge voltage measurements. The estimated values were $4.7\times 10^{\text {-3}}$ for polyimide (PI) and $7.5\times 10^{\text {-3}}$ for polyethylene (PE). Applying these values in DBD simulations suggests the potential to estimate discharge voltages under various pressure conditions. These findings imply that DBD simulations can enhance the accuracy of predictions of discharge phenomena in twisted pairs of enameled wire.