Prediction of v-t Characteristics of air at different pressures

The breakdown characteristics of any given insulation is determined by its voltage-time (v-t) characteristics. The superior characteristics of compressed air will mitigate the use of SF6 gas in Medium voltage circuit breakers and indoor design gas CB. In order to analyze the performance of compressed air experiments are carried out for various pressures and waveshapes and compared for different electrode configurations. In this paper voltage-time (v-t) characteristics are extracted for different pressures ranges from 30 mbars to 4000 mbars for impulse overvoltage ranging from 0.064/50μs, 0.4/50μs and 1.2/50μs. The breakdown characteristics are compared for uniform field and non-uniform field configurations. The Parametric constants A and B are obtained using hyperbolic model. The A and B constants are predicted for pressure of 2000 mbars and are compared with the experimental data obtained and error percentage are found.