Couplings between a resonant current source power supply and a DBD excilamp
H. Piquet1, D. Florez2, X. Bonnin1, A. Belinger3, R. Diez2
1Institution Toulouse University. Institut National Polytechnique de Toulouse, 2 rue Camichel-31071 Toulouse cedex, France
2Pontificia Universidad Javeriana, Carrera 7, N 40-62 Faculdad de Ingenieria-110231 BogotГЎ, Colombia
3Toulouse University. UniversitГ© Paul Sabatier, 118, route de Narbonne-31062 Toulouse cedex 9, France
Keywords: dielectric barrier discharge, excimer lamps, power supply, optimization, resonant inverter, UV
Abstract
This paper presents a study of couplings which take place in systems where dielectric barrier discharge (DBD) excimer lamps are supplied with current source electrical power generators. Causal analysis, using the fundamental properties of the DBD, is used for the design of such current sources. A two steps approach is developed here: in order to control the lamp power, with the best efficiency concerning the UV emission, a current shape controlled current generator is set-up to investigate the possible degrees of freedom of the current waveforms: frequency, peak current, pulse duration. On this basis, “optimized” supplying conditions are selected, and a second power generator with high electrical efficiency is designed: its operating mode combines discontinuous current mode and soft-commutation (ZCS), obtaining as well low electromagnetic emissions and reduced switching losses. A classical electrical equivalent model of the lamp is used to achieve the state plane analysis and to calculate all the electric variables involved in the design of the converter and consequently to select its components. The mathematical relationships obtained from this process, especially those concerning the control of the injected power by means of the available degrees of freedom, are validated with simulations and experimental results. Experimental UV emission performances are presented as well.
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