DEVICE FOR BLOCKING RELAY PROTECTIVE GEAR IN CASE OF FAULT IN SECONDARY CIRCUITS OF POTENTIAL TRANSFORMER

摘要

FIELD: electrical engineering, relay protective gear where actuating input quantities are voltages, including zero-sequence voltages, or those used as self-contained devices monitoring condition of potential transformer secondary circuits connected in star or in open delta. SUBSTANCE: device has multiwinding transformer 1 with one secondary winding connected through rectifier 2 to responding element 3, three primary windings first of which is connected to neutral and to all phases of potential transformer secondary windings connected in star through series resistors 4,5,6 equal in two phases and unequal to them in third phase; second primary winding is connected through series resistor 8 to potential transformer secondary phase of same polarity as third phase of star connected in open delta; third primary winding is connected through series resistor 7 to starting lead of one secondary winding and to finishing lead of other secondary winding of two other phases of open delta. EFFECT: enlarged functional capabilities. 3 dwg