Title :
Filamentary electromechanical breakdown
Author :
Fothergill, J.C.
Author_Institution :
Dept. of Eng., Leicester Univ., UK
fDate :
12/1/1991 12:00:00 AM
Abstract :
A breakdown mechanism is proposed in which a filamentary-shaped crack propagates through a dielectric, releasing both electrostatic energy and electromechanical strain energy stored in the material due to the applied electric field. The mechanism predicts a breakdown strength which is proportional to the fourth root of Young´s modulus and a time to breakdown comparable with that taken for a sound wave to cross the dielectric (≈0.1 μs in 25 μm thick polyethene films). Analysis of previously unexplained results of M. Hikita et al. (1985) on thin films of polyethylene yields good agreement with the proposed mechanism and a filament radius which is comparable to the gross morphological features of the dielectric
Keywords :
electric breakdown of solids; electric strength; polymer films; 25 micron; Young´s modulus; applied electric field; breakdown mechanism; breakdown strength; electromechanical strain energy; electrostatic energy; filamentary-shaped crack; gross morphological features; polyethene films; time to breakdown; Capacitive sensors; Current measurement; Dielectric breakdown; Dielectric thin films; Electric breakdown; Electrodes; Electrostatics; Plastic films; Polyethylene; Voltage;
Journal_Title :
Electrical Insulation, IEEE Transactions on
