LLC inverter design for driving surface DBD optimized for airborne bacteria inactivation

Abstract

This paper proposes a design for an LLC resonant inverter with reflecting plasma characteristics to improve indoor air quality. A surface dielectric barrier discharge (SDBD) helps improve indoor air quality since it effectively inactivates airborne bacteria. By collaborating with plasma physics and power electronics, this study electrically models the SDBD structure. Thus, it presents a compact and commercially viable plasma generation circuit to drive the SDBD feature. The traditional LLC inverter design procedure is not optimized for such an application due to utilization differences. An LLC resonant inverter operating in the resonant mode combined with a step-up transformer is optimally designed to generate a 4-kV(pk-pk), 7.8-kHz sinusoidal voltage with a total power consumption of less than 2.5 W. By investigating optical emission spectroscopy (OES), the production of a reactive species for the inactivation of airborne bacteria is confirmed. Furthermore, the sterilization performance is tested by observing the removal rate of the Staphylococcus epidermidis (S. epidermidis) bacteria inside a 1 m(3) chamber.