METHOD FOR DETERMINING SHORT CIRCUIT PLACE IN POWER TRANSMISSION LINES WITH SERIES COMPENSATION WITH DOUBLE-END NON-SYNCHRONISED MEASUREMENT

摘要

FIELD: electricity.;SUBSTANCE: distance to short circuit place and short circuit resistance is determined by means of voltage and current values, measurement at stations (A) and (B) before and after the short circuit appears. Based on the consumption that short circuit appears in the line section between station A and device from series capacitor and metal-oxide varistor there determined is synchronisation angle δ_A in e^jδA units. Based on the consumption that short circuits appear in the line section between station B and device from series capacitor and metal oxide varistor there determined is synchronisation angle δ_B in e^jδв units. Then, taking into account the model of line with distributed parameters, distance to short circuit (d_A) or (d_B) is determined by the following formula: d_A=P_scd_LA, d_B =(1-p_sc)d_LB where: d_LA, d_LB - hypothetic distance to short circuit, which is expressed in the ratio to length (p_scℓ), the value of which is obtained by means of iterative method using e^jδB and e^jδA. The, equivalent impedance of compensation block at the short circuit stage and is calculated using the values after short circuit of measured voltage and currents, and equivalent impedance of compensation block before short circuit (Z_{SC1_pre}) is calculated in order to determine which of the distances (d_A) or (d_B) is final result.;EFFECT: design load is reduced and accurate synchronisation is provided.;2 cl, 12 dwg