Threshold of space charge injection and electroluminescence in polymeric insulation

Results of EL emission in flat-sheet samples of polymeric insulation (polyethylene), subjected to a uniform field, from two laboratories, are compared. The EL technique has been employed to detect space charge injection, trapping and recombination centers in the material. The voltage has been varied over a range often found in practice, and the frequencies used cover a part of the spectrum used in electrical and electronic apparatus. The aim of this collaborative project is to enhance the understanding of the aging mechanisms of dielectrics in service, determine the threshold field of space charge injection and provide the electrical and electronic industry with guidelines that would reduce the probability of catastrophic insulation breakdowns.