Improvement of breaking capability of vacuum circuit breaker using controlled fault interruption

Vacuum circuit breaker (VCB) is being developed to high-voltage and huge-current area, and a key problem is how to improve the fault interruption capability of VCB. Controlled fault interruption (CFI) technology can pre-estimate a usable zero-crossing after fault and make VCB open on a suitable time. The arcing time, arcing current integral and fault clearing time under CFI and non-controlled fault interruption (non-CFI) were compared using CFI algorithm simulation programmer. CFI failure interval was defined and analyzed. The results showed that the arcing time was reduced significantly, and the contact burning was weakened under CFI. CFI was especially suitable for VCB's and can improve VCB's interruption capacity and interruption success rate, reduce the contact burning and improve the life of an interrupter. To reduce opening time dispersion and the prediction error of zero-crossing can decrease the CFI failure interval and further improve the effect of interruption.