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This work describes the experimental activity and the analyses carried out to investigate more in depth the application of the Voltage Holding Prediction Model (VHPM) to predict the Lightning Impulse Voltage (LIV) breakdown probability of medium-voltage Vacuum Interrupters (VI). A new experimental campaign on two different VI models produced by Siemens, with same rated voltage but different structural features, has been carried out at the high voltage laboratory of the Industrial Engineering Department of the Padua University by systematic application of LIV pulses (up to 345 kV) on several samples of the two VI models. The comparison between the measured and predicted breakdown probabilities of one VI model is the main topic of this work.
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