METHOD AND RELAY OF ADAPTIVE REMOTE PROTECTION FOR POWER TRANSMISSION LINES Russian patent published in 2011 - IPC H02H3/40 G01R31/08 

FIELD: electricity.

SUBSTANCE: short circuit current (I_F) flows via transient resistance (R_F) at short circuit point. First, by means of certain algorithm there calculated is total resistance (Z_relay) of short circuit loop on the basis of phase voltages (V_ph1, V_ph2, V_ph3) and phase currents (I_ph1, I_ph2, I_ph3). Then, there determined is shift (ΔZ) of total resistance of short circuit loop on the basis of total resistance (Z_relay) of short circuit loop, total resistance of (Z_1L) of power transmission line for direct sequence of currents and phase angle (γ) of complex coefficient (k_F) of short circuit current distribution; at that, coefficient (k_F) of short circuit current distribution represents ratio of current (I_relay) of short circuit loop to short circuit current (I_F). Finally, there calculated is distance (d) to short circuit place by subtracting shift (ΔZ) of total resistance (Z_relay) of short circuit loop and by dividing the result by total resistance (Z_1L) of power transmission line for direct sequence of currents.

EFFECT: improving protection accuracy and reliability.

6 cl, 2 dwg, 5 tbl