Analyse par méthode analytique du comportement d'un générateur à induction à triode haute fréquence pour torche à plasma inductif

Abstract

This paper presents an analytical method of analysis of the working of an induction triode high frequency generator, called COLPITTS, used for inductive plasma torch applications. After recalling the principle of an inductive plasma torch, different electrical variants of a COLPITTS are given. All these variants led to a unique simplified electrical scheme which is analysed with power electronic notions and also by taking in account the simplified anode characteristics of the triode. This leads to analytical explicit to expressions of all electrical values, showing two different possible working ratings of the triode, depending on the value of the electrical charge of the generator. At last, a numerical application on a given triode type shows how the application of this method, by determination of all the electrical values, gives a good knowledge of the right working conditions for a given application