Distance protection measurement method of double-circuit line on the same pole

Abstract

The invention discloses a six-phase-sequence-impedance-based distance protection measurement method of double-circuit lines on the same pole. Two circuit lines are viewed as a whole body. Six single-phase ground impedance measuring elements, six interphase impedance measuring elements and six interline impedance measuring elements are formed by three voltages and six currents in the two circuit lines on the side of the whole body. Totally eighteen measuring impedances are formed. The measurement equation of the distance protection measuring method is as shown as the accompanying drawing, wherein UIAu, UIBu, UICu, UIIAu, UIIBu and UIICu respectively denote voltage drops of A, B and C on the unit length of a circuit line I and a circuit line II, ZS denotes line self-impedance, Zp denotes interphase mutual impedance of the same line, ZM denotes interline mutual impedance, L denotes line length, iIA, iIB, iIC, iIIA, iIIB and iIIC respectively denote A, B and C phase currents, and delta denotes interline zero-sequence mutual inductance compensation coefficient.

Description

technical field The invention belongs to the field of electricity, and in particular relates to a novel distance protection measurement method suitable for parallel double-circuit lines on the same pole. Background technique my country's rapidly developing economy has an increasing demand for electric energy, and ultra-high voltage, large-capacity, and long-distance transmission lines will become the mainstream of power grid construction in the future. The double-circuit line on the same pole has the advantages of saving outlet corridors, large transmission capacity, less investment, quick results, improved power supply reliability, and simple operation and maintenance. It can well adapt to the requirements of modern power systems such as reliability, economy, and large transmission capacity. , so it has been widely used. Double-circuit or multi-circuit power transmission technology on the same pole is a comprehensive technology involving multiple fields and disciplines. I...

AI Technical Summary

Problems solved by technology

Since the zero-sequence current of the two-circuit line is related to the systems on both sides, line parameters, fault point location, and fault type, this blocking area is not easy to determine

It can be seen that due to the particularity of faults in double-circuit lines on the same pole, zero-sequence protection and distance protection, which are widely used on single-circuit lines, cannot meet the requirements of double-circuit lines on the same pole.

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