Temperature and Electric Field under Pulse Voltage along the Stress Grading System of a Form-Wound Coil

Simulation studies under pulse voltage using a 2D axisymmetric model in COMSOL® 5.3a on the temperature and electric field along the stress grading system (SGS) of a form wound coil are reported in this work. The validity of the 2D model is shown by comparing the results with the measured temperature profile along the SGS. The effect of the nonlinearity of stress grading tape (SGT) conductivity is evaluated on both temperature and electric field. The results show that increasing the level of the nonlinearity of the SGT conductivity reduces the maximum electric field. On the other hand, the temperature rise is decreased by reducing the level of the nonlinearity of the SGT conductivity. As such, the effect of nonlinearity changes are not mutually compatible in controlling both the electric field and temperature profiles.