The invention discloses a generator outlet PT disconnection early warning device and early warning method, belongs to the technical field of thermal power
plant electric power facility protection monitoring, and solves a problem that early warning cannot be carried out in advance for initial faults of a
voltage loop. The device comprises
voltage transmitters and an analog quantity input module, wherein the three
voltage transmitters are respectively connected with three secondary small buses of a voltage
transformer, the analog quantity input module comprises a voltage sampling module, a
differential pressure module, an absolute value module, a comparison module, a one-out-of-three module, a time
delay module and an alarm module which are connected in sequence, and the voltage sampling module is connected with the voltage transmitters. The method comprises steps of taking a voltage value, calculating a voltage difference, taking an absolute value, comparing, delaying judgment and giving an alarm. The device is advantaged in that logic calculation is carried out through the analog quantity input module, the early warning information is obtained, an
alarm signal is sent out, early warning is sent out when an initial fault occurs in a
voltage loop, on-duty and maintenance personnel are reminded to check a PT primary loop and a PT
secondary loop, and accident expansion is prevented.