Small current grounding line selection device and line selection method

Abstract

The invention discloses a small current grounding line selection device and line selection method, thereby improving the line selection precision. The device comprises an AC input conversion module for isolating and transforming an input analog signal and transmitting the converted analog signal to an A/D conversion module, the A/D conversion module for collecting an analog signal and transmittingthe signal to a CPU module, a switch input module for collecting a switch-in amount and transmitting the information to the CPU module, the CPU module for selecting the collected analog amount as line selection sample data, carrying out fault line determination, and outputting a switch-out amount to a switch-out output module, and the switch-out output module for receiving the switch-out amount outputted by the CPU module and controlling turning on/off of an external device.

Description

technical field [0001] The disclosure relates to a small current grounding line selection device and a line selection method. Background technique [0002] At present, the distribution network operation mode of 35kV and below in my country mostly adopts the small current grounding operation mode. When a single-phase ground fault occurs in this operating mode, the short-circuit current is very small, and the fault line cannot be quickly identified. Therefore, it is particularly important to quickly and accurately select the fault line when a single-phase ground fault occurs. [0003] When a small current single-phase ground fault occurs, the power grid can still run for two hours in this state because the line voltage of the system remains symmetrical, and there is no need to trip immediately. However, due to the increase of the non-fault relative ground voltage, it is easy to break down the weak points of the insulation in the system, and may develop into a two-phase or thr...

AI Technical Summary

Problems solved by technology

[0005] (1) There is an error in the wiring of the small current grounding line selection device, the line selection method is insufficient, and the grounding line is falsely reported, which will cause a power outage on the normal operating line and seriously affect the reliability of the power supply

[0006] (2) The control personnel use the "road-pull method" to try to pull the running line, which may easily cause power outages on the normal running line and seriously affect the reliability of power supply

[0007] (3) The data processing performance of the small current grounding line selection device is weak, which prolongs the grounding fault troubleshooting time, which may cause weak points in the insulation in the system to break through, and develop into a two-phase or three-phase short circuit, affecting the reliability of power supply

[0008] The existing line selection method only singlely gives which line is faulty, but the accuracy of fault judgment under different conditions is not high. In addition, the single result of the existing line selection method is not conducive to the use of information fusion technology for comprehensive judge

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