A corona Investigations

Abstract

The increasing need for more and more energy consumption has made it necessary to use higher and higher transmission voltages. Many technical problems have emerged as a result of the use of such voltages. One of these problems is the occurrence of corona discharges and the associated power losses. Earlier studies of A.C. corona were started by Peek, who provided valuable information concerning the corona onset voltages, corona power loss and spark over voltages for different conductor arrangements. The Edison Electric Institute together with a group of companies have under taken considerable research work on discharges on a project EHV trans- mission line and a great amount of' work was presented which threw more light on the design of' EHV trenSt1ission lines on the basis of economic corona power loss. Despite the wealth of information on corona and its associated power 1oss measurements, little effort has been made to investigate the physical mechanism involved during the growth the of A.C. corona discharges. Thus, this work is intended to explain some of the physical processes undergone during A. C. corona occurrence Oscil1ographic recordings have been made of the Current pulses occurring during corona growth from smooth and stranded conductors of different diameters centered in a hexagonal mesh. Measurement were also made of’ the corona power loss in room air for the different conductors and the effect of' flowing air on this loss was investigated. The results obtained have provided information which may give a better understanding of the physical processes governing the growth of A.C. corona discharges.