In a bushing used on a 36 kV 3-phase line consisting of two different insulating layers with relative dielectric constants Ԑr1= 1 and Ԑr2= 4, the conductor diameter is 25 mm and the flange (pedestal) diameter is 200 mm. There is air in the first layer and its puncture strength is Ed1= 30 kV/cm. Calculate the smallest value of the thickness of the air layer so that there is no discharge.

In a bushing used on a 36 kV 3-phase line consisting of two different insulating layers with relative dielectric constants Ԑr1= 1 and Ԑr2= 4, the conductor diameter is 25 mm and the flange (pedestal) diameter is 200 mm. There is air in the first layer and its puncture strength is Ed1= 30 kV/cm. Calculate the smallest value of the thickness of the air layer so that there is no discharge.

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter4: Transmission Line Parameters

Section: Chapter Questions

Problem 4.36MCQ: When the electric field strength at a conductor surface exceeds the break-down strength of air,...

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