THREE-PHASE POWER TRANSMISSION LINE CONNECTION MODE Russian patent published in 2009 - IPC H02H3/06 

FIELD: electricity.

SUBSTANCE: invention relates to the filed of electrical power engineering and is to be implemented in protective relay and automation equipment for control over connection of three-phase power transmission lines (PTL). The proposed mode envisages the sequence of operations being as follows: phase 1 connection, phase 2 and phase 3 voltages measurement, check-up of each of the voltage values measured for being lower than the first reference value; in case the check-up yields positive results one proceeds with phase 2 connection, phase 3 voltage measurement, check-up of the phase 3 voltage value measured for being lower than the second reference value; in case the check-up yields positive results one proceeds with phase 3 connection; in case any check-up yields negative results or there is a protective relay signal for disconnection of the currently connected phase the subsequent phases remain unconnected and the previously connected ones become disconnected. After connection of phase 1 and measurement of phase 2 and phase 3 voltages one additionally performs check-up of each of the voltage values measured for exceeding the third reference value. The first and the second reference values are taken to be equal to 75-85% of the rated phase voltage value; the third reference value is taken to be equal to 5-15% of the rated phase voltage value.

EFFECT: elimination of the risk of interphase fault close-in of a line having all its phases disconnected combined with the mode realisation simplification.

5 cl, 1 dwg