POWER DIRECTION RELAY Russian patent published in 1996 - IPC

FIELD: electrical engineering; process control and protection systems of turbine-generator sets to check turbine stop valves for upsetting by determining moment of turbogenerator transfer to running as motor sa as to improved relay sensitivity. SUBSTANCE: relay has pulse shaping unit 1, relay operating region shaping unit 2, coincidence unit, monostable multivibrator, pulse-potential converter, incorporating operation delay and reset provision, relay region correction unit responding to load current. Relay functions as follows. With forward direction of power, pulses of shaping units are in phase, short-time pulses start arriving from coincidence unit at supply mains frequency; these pulses are stretched by unit; converter operates and yields d.c. signal corresponding to relay operation. EFFECT: improved relay sensitivity. 1 dwg