Current-Mode Power Converter for Radiation Control in DBD Excimer Lamps

Abstract

A pulsed current-mode converter specifically designed for the supply of dielectric barrier discharge excimer lamps is proposed in this paper. The power supply structure is defined on the basis of causality criteria that are justified by the structure of the lamp model. The converter operation is studied, and its design criteria are established using state-plane analysis. This converter, operating in discontinuous conduction mode, controls directly both the amplitude and the duration of the emitted ultraviolet (UV) pulses. Experimentally, the UV radiation is demonstrated to be proportional to the current injected into the gas, and the degrees of freedom offered by the control of the supply are shown to be very efficient for the active control of the UV power.

Atmospheric Pressure Low Temperature Direct Plasma Technology: Status and Challenges for Thin Film Deposition

“…Most of the literature deals with voltage sources. However, there is some research related to current power supplies for DBDs 127–129. The main benefits are a better control of the discharge current, an increase of the discharge duration and therefore an increase of the discharge power without transition to thermal plasma 130…”

Square-Shape Current-Mode Supply for Parametric Control of the DBD Excilamp Power

“…There are evidences of correlation between the shape of the current injected into the gas and that of the instantaneous UV radiation [8], [10].…”

“…The lamp current frequency will be varied from 50 to 200 kHz; this range has been selected on the basis of previous results presented in [1], [8], [10], and [32], concerning the discharge regime and the lamp efficiency.…”

“…Due to the capacitive nature of the DBD (see Fig. 1-bottom) [9], the lamp current must be bidirectional to avoid the indeterminate growing of the lamp voltage [10].…”

Designing the high voltage transformer of power supplies for DBD: Windings arrangment to reduce the parasitic capacitive effects

“…Fig.1 reminds the principle of topologies, proposed on the basis of causality reasoning [5,6], to supply DBD devices with an efficient control of the operating conditions. It exhibits an equivalent circuit of the DBD, which is modeled as follows [7]: C d represents the dielectric barriers that separate the discharge gas from the power supply metallic electrodes; C g characterizes the gas when it is non-conducting and G gas stands for the gas conductance after its breakdown.…”