Protection of Electrical and Electronic Systems against Surges by an Isolation Transformer

摘要

Przepi?cia wywo?ane przez wy?adowania piorunowe w s?siedztwie linii s? jedn? z podstawowych przyczyn uszkodzeń urz?dzeń systemów elektrycznych i elektronicznych. Podano uproszczone zale?no?ci do wyznaczania liczby analizowanych udarów. Badano w?a?ciwo?ci jednofazowego podwójnie ekranowanego izolacyjnego transformatora. Pomiary przeprowadzono ekranem uziemionym lub nieuziemionym. Wykazano, ?e nieprawid?owo uziemiony ekran transformatora mo?e wyeliminowa? efekt ochrony.%Surges due to flashes to and near a line, are one of the main causes of damage to equipment of the electrical and electronic systems within a structure. Simplified formulae are given for an approximated evaluation of the number of considered surges. The effectiveness of single-phase double screen isolation transformer in the attenuation of common mode transient voltage is investigated. Tests were performed with its ungrounded and grounded screens. It is shown that a not correct grounding of the transformer screen may eliminate the effect of protection.