Prediction of lightning impulse voltage induced breakdown in vacuum interrupters

In this work, we investigate the Lightning Impulse Voltage LIV breakdown probability of different medium-voltage Vacuum Interrupter (VI) tubes manufactured by Siemens; for this investigation, the Voltage Holding Prediction Model (VHPM) has been employed. The study focuses on results of systematic LIV experiments (up to 250 kV) carried out in the Siemens VI factory on different VI configurations and aimed at validating the VHPM under impulsive voltage and in well-controlled conditions. In order to assess the predictive capability of the VHPM, the model has been applied to a tube configuration with unknown voltage breakdown characteristics exploiting Weibull parameters obtained from the analysis of tube configurations with well-known LIV features. Experiment and simulation showed fair agreement concerning the overall VI breakdown probability as a function of the voltage applied to the contact electrodes.