Transformer Oil Dielectric Strength in the Contact Gap of the Explosive Arc-Extinguishing Device

I O Muravlev,N F Uvarov,M A Surkov,Kh Tsoggerel,E V Tarasov

doi:10.1088/1757-899x/189/1/012018

Abstract

The article describes the experimental results on the breakdown of the high-speed flow of transformer oil. In real conditions, the flow moves in the contact gap of a high-voltage explosive switch with speeds from 67 to 152 m / s. The geometry of the contact gap is sharply inhomogeneous and forms turbulence in the flow zone. In the arc chute medium the air inclusions pass from the dissolved state to the gaseous and the emerging bubbles enter to the electric field. Breakdown occurs, mainly through gas inclusions. In the moment, the gradient of the breakdown voltage is reduced by 91.6% compared to the static state of the oil. The experiments were carried out on the model of a high-voltage explosive switch, connected to the power circuit of the surge generator. The probing of the gap was made by a standard pulse of 1.5 / 50 μs. As a result, the dependences of the gradient of the breakdown voltage on the flow rate of the transformer oil for the usual geometry of the high-voltage explosive switch contact system are constructed.

Highlights

The study of arc extinguishing process in the explosive switch model allowed to explain its high current-limiting effect of the high speed arc extinguishing fluid on the electric arc [1]
Methods of the Experiment Experiments on the dielectric strength of the transformer oil flow were performed on a model of the explosive switch contact system, simulating the beginning of a current conductor movement (Figure 2)
To find out how the dynamics of the contact gap formation affects the gradient of the breakdown voltage at the curve points 67 m/s and 152 m/s in Figure 4 a series of experiments for 2 mm gap was conducted

Summary

Introduction

The study of arc extinguishing process in the explosive switch model allowed to explain its high current-limiting effect of the high speed arc extinguishing fluid on the electric arc [1]. The final stage of the high-voltage circuit shutdown process is determined by the recovery speed of contact gap electric strength. 2. Methods of the Experiment Experiments on the dielectric strength of the transformer oil flow were performed on a model of the explosive switch contact system, simulating the beginning of a current conductor movement (Figure 2).

Results

Conclusion