METHOD AND DEVICE FOR TRANSMITTING AND RECEIVING RELAY PROTECTIVE GEAR SIGNALS Russian patent published in 2006 - IPC H02H3/30 

FIELD: high-frequency relay protective gear of power transmission lines.

SUBSTANCE: proposed method includes transmission of two-position blocking signal, monitoring signal, and n^th signal instruction shifted in frequency relative to carrier fo. In absence of instructions from relay protective gear blocking signal is transmitted at frequency fo ± Δf, where Δf = Fk is desired frequency shift of monitoring signal. During transmission of n^th instruction Δf = Fn, where Fn depends on number of n^th instruction. Blocking signal is received by determining polarity of signal frequency deviation from carrier; monitoring signal and n^th instruction are found by determining Δf. Device implementing this method has generator unit that functions on transmission end for generating frequency-keyed variable-deviation carrier and is provided with control and keying circuits. On receiving end device has instruction decoder designed for decoding n^th instruction by deviation of frequency-keyed signal and blocking signal decoder designed for determining blocking signal by polarity of deviation of received signal frequency from carrier.

EFFECT: reduced frequency band of high-frequency communications, enhanced noise immunity in blocking signal transmission, reduced cost, simplified design of equipment.

6 cl, 4 dwg