Three-phase overhead line model for laboratory testing of fault passage indicators

For development and testing of Fault Passage Indicators (FPIs) a laboratory model of a three-phase overhead line has to be constructed. For reasons of current source intensity and space limitations in laboratory conditions, the phase currents and support pole dimensions should be properly scaled in order to achieve same values of magnetic flux density that would appear in normal FPI operating conditions. Scaling laws for calculating the phase currents for different types of faults and various support pole dimensions of the three-phase line model are proposed in this paper. Scaled fault currents and dimensions of the three-phase line model are calculated using the proposed scaling equations and a laboratory model is constructed. The proposed methodology is verified by measurements on the laboratory model.