Ablation-Assisted Current Interruption in a Medium Voltage Load Break Switch

Conference: ICEC 2014 - The 27th International Conference on Electrical Contacts
06/22/2014 - 06/26/2014 at Dresden, Deutschland

Proceedings: ICEC 2014

Pages: 6Language: englishTyp: PDF

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Authors:
Gjendal, Gaute Jensen; Jonsson, Erik (Norwegian University of Science and Technology, Trondheim, Norway)
Runde, Magne (SINTEF Energy Research, Trondheim, Norway)

Abstract:
Near an electric arc some polymers, known as ablation materials, change the properties of the arcing medium in a beneficial manner. The interruption capability for current interruption improves by increasing the pressure and the heat dissipation from the arc. The present paper studies medium voltage (MV) current interruption by ablation. In an MV test laboratory, current interruption experiments are carried out with polypropylene (PP) ablation plates. Both the current and transient recovery voltage are varied. The results reveal that the PP ablation has the potential to interrupt the thermal phase for all tested currents, up to 800 A. The dielectric strength in the arcing zone after the thermal phase is however poor, and dielectric re-strikes easily occur, causing the interruption to fail.