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E. Lawera, M. Mlkrut

ANALYSIS OF THE PROPACATION OF GROUND FAULT CURRENTS IN UNEARTHED RING NET- • • WORKS (PROM THE POINT OF VIEW OF PROTECTION CHOICE

S u m m a r y

The paper is deroted to the analyals of the propagation of ground fault currents ln unearthed networks wlth ring connezlons. On the basls ot inwes-tlgatlon of 6 kV diatrlbutlon networks in coal alnes the structure and para-< meters of model networks accepted for analysis as well as thelr equlvalent diagram were found. For thesa networks the multl-rarlant calculatlons of ground fault currents were madę and the results of quantitatlve analysis of thelr propagation ln ring connexlons were given. The concluslons were pre-sented on crlterlons and prlnciples of protecting the ring networks from one-phase, llne-to-earth fauls.