Protective system for voltage transformers

摘要

The subject of the invention is a protective system for voltage transformers, finding application in the attenuation of ferroresonant states occurring in voltage transformers in high and medium voltage grids. A protecting system for voltage transformers comprising a damping burden (3) connected into an open delta system of three auxiliary secondary windings of three single-phase transformers (VT1, VT2, VT3), which is activated and deactivated by a switching element (2) connected in series with the damping burden (3). The protective system is characterised in that the switching element (2) has a control input (C) connected to an output of control means suitable for controlling a time sequence of deactivating the damping burden (3) by controlling the conductive and nonconductive states of the switching element (2).