Measurement method of voltage amplitude and phase angle at non-identical phase-cross-line grounding fault point of double-circuit line

Abstract

The invention discloses a voltage amplitude and phase angle measuring method for a double-circuit line non-same-name-phase overline grounded fault point. The method includes the steps that the fault phase voltage, the fault phase current and the zero-sequence current of a protecting and installing position of a circuit line I of a double-circuit line on the same tower are firstly measured; the phase angle of the zero-sequence current of a circuit line II of the double-circuit line on the same tower is calculated, and the zero-sequence current of the circuit line II of the double-circuit line on the same tower is calculated; the voltage amplitude of the double-circuit line non-same-name-phase overline grounded fault point is calculated. Only single-end single-circuit line electric amount is used without introducing the electric amount of the other circuit line, and measurement results are not affected by changes of operation modes of the electric power system. Influence on accuracy of measuring the voltage amplitude of the double-circuit line non-same-name-phase overline grounded fault point by zero-sequence mutual inductance between the lines, transition resistance and a load current is eliminated, and the measuring method is high in measurement accuracy.

Description

technical field [0001] The invention relates to the technical field of electric power system relay protection, in particular to a method for measuring the voltage amplitude and phase angle of a double-circuit line with non-identical phases across lines to ground fault points. Background technique [0002] Through the real-time measurement of the voltage of the double-circuit line's non-identical phase-crossing ground fault point voltage, it is helpful to timely grasp the influence of the non-identical phase-crossing ground fault of the double-circuit line on the thermal stability and dynamic stability of the parallel double-circuit line on the same pole. To ensure the safety of parallel double-circuit lines on the same pole and the stability of the power grid provide a reliable basis for decision-making. [0003] Through the real-time measurement of the voltage of the double-circuit line's non-identical phase-crossing ground fault point voltage, the online diagnosis of the d...

AI Technical Summary

Problems solved by technology

[0004] However, at present, in the field of relay protection technology, a measurement method that can accurately calculate the voltage of the ground fault point of the non-identical phase of the double-circuit line with the same pole has not been proposed. The thermal stability and dynamic stability of double-circuit lines paralleled on the same pole provide a reliable basis, and it is also unable to provide a basis for diagnosing the ground fault types of non-identical phase-crossing lines of double-circuit lines

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