Effect of transformer winding on the transient response of power transformer bushings

This paper deals with the response of power transformer bushings under the effect of transformer windings during electromagnetic transients such as lightning. In transient domain, investigating the characteristic of each power component separately in the network wouldn't be adequate. Each component can make an influence on the transient current and voltage that may be measured from another one. This paper proposes to find the effect of transformer windings on the transient response of the bushing, which contains valuable information on bushing's condition. It may result helpful in diagnostics of such an important power component to avoid catastrophic failure. Natural transients would be helpful in monitoring of the bushing by utilizing them as stimuli for online dielectric response measurement. Transient response of the lumped model of the bushing in EMTP is compared with its finite element model (FEM) in COMSOL Multiphysics to validate the robustness of modeling approach. According to the frequency component of the lightning, transient electromagnetic wave module of COMSOL is applied. Then, the effect of the transformer winding on the transient response of the bushing is investigated in EMTP.