A current-based solution for transformer differential protection.I. Problem statement

摘要

This paper analyzes the problem of transformer differentialnprotection. First, the authors review the concept of transformerndifferential protection. They then analyze magnetizing inrush,noverexcitation and current transformer (CT) saturation phenomena asnpossible causes of relay misoperation. Finally, they summarize thenexisting methods for discriminating internal faults from inrush andnoverexcitation conditions