SAFE OPERATIONAL METHOD OF REDUCING ACTIVE VOLTAGE OF GROUND-FAULT PHASE OF SWITCHED OFF GROUNDING SYSTEM Russian patent published in 2020 - IPC H02H9/02 

FIELD: electric power engineering.

SUBSTANCE: use: in electric power engineering. According to the method of transformer winding on the side of inefficient grounding system are equipped with several shunt steps; in case of single-phase ground fault there selected is shunting stage of winding of phase of occurrence of short circuit for short-circuiting directly to ground or through the impedance to reduce the fault-in-phase voltage in order to provide the voltage value at the closure point below the grounding voltage of the electric arc-burning circuit in order to meet the long-term continuous safe operation requirements.

EFFECT: enabling elimination of instantaneous single-phase earth fault, damping of long-term current of single-phase earth fault, limitation of growing amplitude of phase voltage without short-circuit and risk of breakdown of insulation of this phase, reduced risks for safety of people and equipment, efficient prevention of failures at power outages and improvement of reliability and safety of power supply.

10 cl, 6 dwg