A proposal to determine the humidity correction factor during lightning lmpulse testing

The humidity correction factor for lightning impulse tests is carried out according to a standard international procedure. However, this procedure is not suitable to application in short distance air gaps typical of medium voltage apparatus. This paper deals with a new proposal to define a humidity correction factor suitable to application in medium voltage apparatus. The developed procedure was based in testing results on sphere-sphere and rod-rod gaps. All the data was obtained at the High Voltage Laboratory of Escola Federal de Engenharia de Itajuba using a 450 kV 1.25 kJ impulse voltage generator. (4 pages)