Grounding fault indicator system considering different line parameters

Abstract

The invention relates to a grounding fault indicator system considering different line parameters and belongs to the power fault detection technical field. The system includes fault indicators, a datacollector and a master station; the fault indicators cooperate with the master station. Transient high-frequency components and direct-current components are utilized to perform judgment. According to a judgment process, the data of the first group of fault indicators of each outgoing line are processed; high-frequency energy is improved by a modifier formula, so that the influence of different line parameters can be decreased; and the larger one of improved high-frequency energy and direct-current energy is selected to perform line selection. After line selection is completed, the corresponding energy information of each group of fault indicators of a fault line is obtained by using the same steps; and when the energy information of the two adjacent groups of fault indicators satisfies requirements, it can be determined that a fault occurs between the two groups of fault indicators. The grounding fault indicator system considering different line parameters of the invention can assistin decreasing data processing quantity, is suitable for systems where a plurality of neutral grounding modes co-exist and has high accuracy in systems with large differences in line length and largedifferences in line parameters.

Description

technical field [0001] The invention belongs to the technical field of power fault detection, in particular to a ground fault indicator system considering different line parameters. Background technique [0002] During the operation of the power system, faults often occur; among them, the number of single-phase ground faults accounts for more than 80%. After a single-phase ground fault occurs, the fault current value has a great relationship with the neutral point grounding mode of the system; while the low-voltage distribution network in my country mainly adopts the operation mode of small current grounding. When a single-phase ground fault occurs in a low-current grounding system, the current flowing through the ground point is only the line-to-ground capacitance current, which is much smaller than the load current, so it will bring many difficulties to fault detection. Therefore, the single-phase ground fault is the most likely to occur but the most difficult to detect. ...

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Problems solved by technology

However, none of the fault indicators are suitable for many power system operating conditions

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