Abstract
This paper presents the results of experimental studies of voltage phenomena in the switching operations of vacuum switching devices made by various manufacturers in several different configurations of 6 kV, 10 kV, 20 kV and 35 kV networks. During switching-on operations of the inductive loads, re-ignition of the electric arc between the contacts of the vacuum switching devices appears. Each arc ignition appearance leads to over-voltages with gradients close to those of lightning over-voltages. Switching-off operations of the inductive loads with vacuum switching devices leads to the cutting-off of the current before it passes through a natural zero and the appearance of multiple re-ignitions of the arc between their contacts. All this leads to significant over-voltages on the equipment insulation. The analysis of surges in the studied networks, and measures and means to reduce the stress of isolation are proposed.
References
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