Neutral point multi-point grounding detection device based on high-accuracy detection current

Abstract

The invention discloses a neutral point multi-point grounding detection device based on high-accuracy detection current. The neutral point multi-point grounding detection device comprises an analyzer, a detector and a clamp meter, wherein a fault analysis module is formed by the analyzer and the clamp meter when in connection, and a fault positioning module is formed by the detector and the clamp meter when in connection. The analyzer adopts a detection current generator designed according to node shunt principle, wherein the detection current generator can achieve high linearity and significantly improve the accuracy of detection. The neutral point multi-point grounding detection device is wide in applicable scenarios and convenient to apply, for example, can be used for judging multi-point grounding of a secondary loop of a current transformer inspected by a transformer substation, and effectively detects whether multi-point grounding of the secondary loop of the current transformer occurs on the premise of ensuring that normal operation of a protective device is not affected.

Description

technical field [0001] The invention discloses a neutral point multi-point grounding detection device based on high-precision detection current, and relates to the technical field of electric power automatic detection. Background technique [0002] In the field of power technology, equipment that produces, transforms, transmits, and distributes electrical energy (such as generators, transformers, and transmission and distribution power lines, etc.), as well as equipment that uses electrical energy (such as motors, electric furnaces, relay protection and control devices, etc.), Even the same whole composed of energy management system is called power system. The composition of the power system can be divided into a primary system (or primary loop) and a secondary system (or secondary loop) according to functional differences: the former is responsible for the transmission and distribution of electric energy, and the latter is used to monitor the primary system (or primary loop...

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Problems solved by technology

[0005] In the patent application with the application number 201310109898.1, a method and system for detecting multi-point grounding of the neutral line network of the voltage secondary circuit are disclosed. However, in this application, conventional detection current injection equipment is used, and the commonly used three-phase current generator is When generating and outputting various AC and DC three-phase current waveforms required for verification, it is impossible to maintain the stability and accuracy of the output current waveform in the audio range from DC, power frequency to 2kHz at the same time, and there are narrow operating frequency bands, The attenuation is more obvious when outputting high-order harmonics, and the high-frequency components of the waveform are easy to induce self-oscillation and other shortcomings, which obviously do not meet the requirements of harmonic energy meter verification.

[0006] In the patent application with the application number 201310565336.8, a non-contact current transformer secondary circuit multi-point grounding detection method and system are disclosed, which use Faraday's law of electromagnetic induction to determine whether there is current in the neutral line. The method also has the disadvantage of low detection accuracy

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