METHOD TO BUILD AND ADJUST RELAY PROTECTION WITH HIGH-FREQUENCY EXCHANGE BLOCKING SIGNAL ALONG LINE WIRES Russian patent published in 2011 - IPC H02H3/00 

FIELD: electricity.

SUBSTANCE: according to the method, from the ends of the line with a leaking power from the ends of each phase, as zero current value is exceeded in each phase, there is a high-frequency locking signal transmitted continuously along the line wires to sets of relay protections at all ends, preventing their operation in working, asynchronous and non-complete-phase modes. In case of external short circuits, by availability of a blocking signal at each end of the line good condition of a high-frequency channel is continuously monitored, in case of external short circuits and its fault, alarm is provided, as well as line switches disconnection is blocked. In case of internal short circuits on the line, due to power leak-in at the ends of the line at least in one of phases the high-frequency blocking signal along the line wires to the sets of relay protections disappears at all ends, and the latter disconnect the switches each at their end.

EFFECT: improved sensitivity.

2 dwg