INVESTIGATION OF THE OPERATION MODES OF PROTECTION AGAINST SINGLE-PHASE EARTH FAULT IN THE NETWORK WITH ISOLATED NEUTRAL POINT IN PRESENCE OF FERRORESONANCE PROCESSES

Abstract

The problem of distribution of zero-sequence currents and modes of protection against single-phase earth fault with the existence of ferroresonance processes are considered in the article. It’s shown that in the ferroresonance mode the false tripping of both electromechanical and digital relaying is possible. There have been considered the typical algorithms of protection against single-phase earth fault that are used by digital terminals of relay protection, and also special feature of their setting and blocking at the ferroresonance mode.