HHT (Hilbert-Huang transform)-based microcomputer small-current earth-fault line selection device

Abstract

The invention relates to an HHT (Hilbert-Huang transform)-based microcomputer small-current earth-fault line selection device which is serially connected with a voltage transformer and then connected to a busbar outgoing line. The line selection device comprises a microcomputer and a plurality of zero-sequence transformers, the microcomputer is provided with serial communication interfaces, the zero-sequence transformers are connected with the microcomputer through the serial communication interfaces, and the zero-sequence transformers are parallelly connected onto the microcomputer. A voltage transformer is in triangular connection with an opening of the microcomputer, the voltage transformer, the microcomputer and the zero-sequence transformers form a circuit connected onto the busbar outgoing line, and the microcomputer adopts HHT line selection. The HHT-based microcomputer small-current earth-fault line selection device has the advantages that by means of HHT for line judgment and selection, oblivion of fault features due to interference and measurement errors is avoided, and sensitivity and reliability in fault line selection are improved; in addition, owing to adoption of the microcomputer for treatment, low cost, easiness and effectiveness in implementation and realization of meeting the requirement on automatic utilization of a power distribution network are achieved.

Description

technical field [0001] The invention relates to a small current grounding line selection device, in particular to a microcomputer small current grounding line selection device based on Hilbert-Huang Transform (HHT), belonging to the technical field of electrical protection. Background technique [0002] Most of my country's 3KV-66KV distribution network adopts the small current grounding method, that is, the neutral point is not effectively grounded, including the neutral point ungrounded system and the neutral point grounded system through the arc suppression coil. The advantage of the non-effective neutral point grounding system is that it can automatically extinguish the arc and restore insulation in most cases when a single-phase grounding occurs. However, when a permanent ground fault occurs, in order to prevent the fault from expanding due to the rise of the non-faulted phase voltage, the fault line must be determined and cut off as soon as possible, which raises the p...

AI Technical Summary

Problems solved by technology

This problem has not been well solved for a long time, restricting the development of distribution network automation

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