METHOD AND DEVICE FOR AUTOMATIC CHECKUP OF NEUTRAL WIRE PARAMETERS IN 0.4-KV OVERHEAD OR CABLE LINES Russian patent published in 2007 - IPC H02H5/00 

FIELD: power engineering.

SUBSTANCE: proposed method and device designed for protecting power consumers against overvoltages caused by inadequate parameters of neutral wire or open circuit in the latter and for ensuring electric-shock, fire, and explosion safety depend for their operation on permanent passage of high-frequency rectangular pulses over neutral-wire - set-of-duplicate-ground-electrodes - ground circuit at difference in channel frequencies of at least 200 Hz. Then arriving signals are filtered off at supply end of line (substation) and decoded, predetermined pulse amplitude is estimated, and faulty line is disconnected in case this amplitude has reduced by more than 15 percent.

EFFECT: enhanced reliability of monitoring neutral wire parameters and checking for open circuit in this wire or in part of duplicate ground stakes at any point of line.

2 cl, 1 dwg, 1 tbl