Small-current grounding line selection device line-outgoing system

Abstract

A small-current grounding line selection device line-outgoing system is connected with a voltage transformer, a grounding loop and a grounding line selection device, and comprises a zero sequence current transformer input terminal, CT ends and zero sequence transformers, which are connected in sequence. The grounding line selection device is connected with a zero sequence current transformer, the voltage transformer and a contactor; by adding the CT ends and the zero sequence transformers or secondary line accessing devices to the current transformer input terminal, use needs of full cable outgoing, overhead line outgoing or mixed line outgoing are met; and when the voltage transformer detects a zero sequence voltage, the grounding loop is controlled to be connected, and then, fault lines are judged according to the current data collected by the zero sequence current transformer. The small-current grounding line selection device line-outgoing system, for line outgoing modes of different landforms, eliminates errors, realizes line fault elimination accurately and quickly, and guarantees normal work of the grounding line selection device.

Description

technical field [0001] The invention relates to an outlet system of a small current grounding wire selection device, in particular to the technical field of electric power detection. Background technique [0002] Most substations of 35KV and below in my country's power grid adopt the neutral point ungrounded method or the neutral point grounded method through the arc suppressing coil. When the grounding line selection system appears single-phase grounding in these two grounding methods, the current flowing through the grounding point is equal to the line distribution. Capacitive current, the value is small. Therefore, these two grounding methods are called small current grounding methods. The advantage of the low-current grounding system is that after a single-phase grounding occurs, the system can supply power normally (usually 2 hours), which provides time for troubleshooting and ensures the normal operation of the power grid system. [0003] Since the power grid layout i...

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Problems solved by technology

[0003] Since the layout of the power grid is greatly affected by factors such as terrain, often different terrains, after the grounding line is single-phase grounded, it will cause different errors in line fault troubleshooting, which will affect the troubleshooting of down-line faults.

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