Characterisation of corona formation for twin-point/plane gaps under HVAC

Corona formation in twin-point/plane gaps is experimentally investigated under HVAC. There are many factors affecting such corona formation. The investigated factors are the spacing between the two points, gap length between the twin-point and the plane, ambient temperature, relative humidity, frequency of the applied voltage, and electrode material. In order to study and explain such phenomena, a photographic investigation together with a simultaneous measurement of both the applied voltage and the corona current are also introduced.