Capacitive-resistive field calculation on HV bushings using the boundary-element method

Capacitive-resistive field distributions including surface and volume resistivities have been computed in and around HV porcelain and capacitor bushings. The boundary element method has been applied for field computation in two axi-symmetric bushing configurations including four dielectrics. Effects of uniform and non-uniform distributions of surface resistivity and volume resistivities of different dielectric media are studied in detail. Special emphasis has been given to the stress distributions along the various dielectric-dielectric boundaries. Further, the values and locations of maximum stresses in different dielectrics are determined and reported in this paper. The plots of equipotential lines for a few typical cases of field distributions are also presented here for both bushings.