Study of behavior of the arc of the circuit breaker mt(15kV) from magnetic diagnostics


B. Hamaidi*, A. Haddouche, M. Ouadi
Badji Mokhtar University Annaba B.P.23000, ALGERIA
Faculty of Engineering Department of Electromechanical
Electromechanical Systems Laboratory

* Corresponding author: E-mail:

Received: 02 February 2011; revised version accepted: 21 July 2011



     Circuit breakers are used in electrical installations where they play an essential role in protecting people and systems against short-circuits and overloads. These circuit breakers utilize the spontaneous appearance of an electric arc current limiting short-circuits in an installation. Technically the breaker must be able to interrupt or establish strong operating current overload or short circuit and also be able to support constraints in electric fields. The value of this electric field is critical to avoid failure of the dielectric break after the extinction of the arc. The geometrical shapes knowledge of the circuit breaker plays a fundamental role in determining the electric field. The problem is then to act on the arc and its dynamics in order to accelerate its extinction, and thus improve the quality of the power interruption. Unfortunately, the electric arc has explosive properties (phenomenon fast and unstable) and destructive to the device. Many physical laws (mechanics of fluids, electromagnetism), intervene and complicate attempts to improve the circuit breakers on the limitation of short-circuit fast extinction of the arc, increase in the number of operation. For that and starting from the magnetic diagnostics, we must conduct studies on the dynamics of the arc in the medium voltage switchgear (MT). The objective is to present a study on the phenomena caused by the presence of separators, the displacement of the arc in order to optimize the cutoff.

The study shows that modeling of circular electrodes generates a factor of Schwaiger very low value and that the electrical constraints are only localised in the vicinity of one electrode.

Keywords: Dielectric; Electrical field-medium voltage circuit breaker magnetic-diagnosis.

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