Small-current grounding line selection method and device

Abstract

The invention provides a small-current grounding line selection method and device. The method comprises the steps of acquiring a capacity current of each circuit at a bus and in an effective frequencyband, allowing a flowing direction of the capacity current to be opposite to those of capacity currents of other circuits, and taking a circuit of which the flowing direction of the capacity currentis opposite to those of the capacity currents of the other circuits as a first pre-selection circuit; acquiring a zero-sequence current of each circuit, and selecting a second pre-selection circuit according to phase characteristic of the zero-sequence current of each circuit; and judging that the same circuit is a fault circuit if the first pre-selection circuit and the second pre-selection circuit are the same circuit. According to the small-current grounding line selection method provided by the invention, steady-state component line selection and transient-state component line selection are combined, so that analysis can be performed from a steady-state component and a transient-state component in a fault signal, whether a corresponding circuit is the fault circuit is further judged, and the line selection reliability is greatly improved.

Description

technical field [0001] The present application relates to the technical field of high-voltage equipment, in particular to a method and device for selecting a small-current grounding line. Background technique [0002] The occurrence of single-phase grounding problems in the operation of high-voltage transmission lines will directly affect the stability of the entire power system and may cause excessive faults. At present, some low-current grounding line selection methods and devices have been introduced in the industry for unidirectional grounding faults in high-voltage transmission lines. However, these methods and devices often have problems of misselection and missed selection in practical applications. Therefore, in practical applications, the line selection device is idle and the user uses the original method of manual switch test to find the grounding line. Contents of the invention [0003] The present application provides a small current grounding line selection m...

AI Technical Summary

Problems solved by technology

However, these methods and devices often have problems of misselection and missed selection in practical applications. Therefore, in practical applications, the line selection device is idle and the user uses the original method of manual switch test to find the grounding line.

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