Scale Model Studies of AC Substation Electric Fields

Energized scale models of EHV/UHV substations can be used as design tools to detennine the electric field distribution. To prove the method, an energized scale model of an existing 345-kV substation has been designed and built. The paper reviews modeling and instrumentation problems and their solutions, calibration and verification tests, and discusses the accuracy of model measurements. Comparison of corresponding test points shows that the agreement between substation and model measurements is good: the mean of absolute values of errors is about 4.6%. In the course of the study, the electric field strength of the model was mapped, and the effects of a wide range of modifications were examined. The feasibility of short circuit (charging) current measurements on model vehicles was also proven.