Electric Field in Polymeric Isolators of the 500kV Voltage Class

Abstract

This study presents a detailed study of the electric field in polymeric isolators of the 500kV voltage class through modifications in the dimensions of the anti-corona ring. That is, by varying the three dimensions of the anti-corona ring: height (h), distance of the anti-corona ring conductor (r) and the diameter of the anti-corona ring conductor (d); it was possible to observe the electric field distribution in a polymeric isolator of the 500 kV voltage class. Such voltage class in currently applied to prevent loss of energy in long transmission lines. However it faces disadvantages, like the problem of the increased corona effect, which besides generating electromagnetic noise, increases the level of the electric field around the conductors and the isolator. The corona effect is responsible for an electric energy loss that is in the order of hundreds of kW/km in TLs and generates noises that reach up to 65dBm. This effect occurs when the air’s critical value is exceeded, causing the electrons to collide with air resulting in the formation of ozone which is a major cause of corrosion in isolators. In this study, this issue is addressed and it is outlined sizing measures for manufactoring the anti-corona ring.