Analysis of switching effects of vacuum circuit breaker on dry-type foil-winding transformers validated by experiments

In this paper, the prestrike and the restrike effects during switching a vacuum circuit breaker (VCB) connected to a dry-type foil-winding transformer are theoretically and experimentally analyzed. The analysis is conducted by performing a wide range of experimental three-phase switching ON/OFF tests for a 3.75-MVA prototype test transformer connected to a VCB by a cable with different lengths and for different loading conditions.