METHOD FOR EFFICIENT EARTHING OF POWER TRANSFORMER NEUTRAL LINE

摘要

FIELD: electrical engineering.SUBSTANCE: invention relates to electrical engineering and can be used for protection of power transformers of electric stations and substations that operate in electric networks with rated voltage of 110 kV and higher against geo-induced currents in periods of geomagnetic activity at space weather perturbations. Method for efficient earthing power transformer neutral line through current-limiting resistor and thyristor switch consists in fact that in case of abnormal and emergency situations is switching thyristor switch, which is connected in parallel with current-limiting resistor and control pulses, thus providing continuous conductivity thyristor switch. Fixed appearance of constant component of currents and second harmonic phase current high-voltage winding of power transformer. In case said currents permissible values of supply of control pulses to the thyristor key. Resumed supply of control pulses only after termination of constant component currents.EFFECT: technical result consists in reduction of losses of active power in current limiting resistor and reactive power in power transformer.1 cl, 1 dwg