Improvement of the Insulation System of Unconventional Combined Instrument Transformer Using 3-D Electric-Field Analysis

This paper presents the new printed-circuit board (PCB) technology medium voltage combined instrument transformer. The capacitors of the voltage transformer and coils of the current-to-voltage transducers are designed and manufactured using PCB technology. The design of the insulation system of the combined transformer was carried out using electric field analysis. The electric field distributions, computed by applying the 3-D finite-element numerical method, are presented. The results for several different applications were compared with tests of real-life models.