Overvoltages during switching operations of vacuum switching devices
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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