Atom-decomposition-method-based detection method for arc-resistance ground fault of small-current grounding system

Abstract

The invention relates to an atom-decomposition-method-based detection method for an arc-resistance ground fault of a small-current grounding system so that an arc-resistance ground fault of a system can be detected quickly and effectively. A fault current is analyzed and an arc-resistance ground fault of the system is detected; when an arc-resistance ground fault occurs at the small-current grounding system, a fault current harmonic generates a certain amount of distortion because of the nonlinearity of the fault resistance; in harmonic energy distribution, the proportion of the energy of thethird harmonic and nearby harmonic components is high relatively; and on the basis of the characteristic of the arc-resistance ground fault, calculation is carried out to obtain a harmonic energy ratio and then a criterion is compared to detect the fault. According to the invention, the atomic decomposition method is used as a fault current signal analysis tool; the high-redundancy atomic libraryis able to capture natural features of the signal well to realize sparse signal decomposition; and the signal expression result is simple and reliable.

Description

technical field [0001] The invention relates to an arc in a small current grounding system, in particular to a method for detecting an arc resistance grounding fault in a small current grounding system. Background technique [0002] Most of my country's distribution network adopts the neutral point indirect grounding operation mode. When a ground fault occurs in this mode, the current at the grounding point is small, which is called a small current grounding system. When a single-phase ground fault occurs in a low-current grounding system, it often develops into an arc ground fault. Arcing ground faults will generate higher multiples of overvoltage, forming two or more point ground faults, resulting in higher overvoltages, which seriously threaten the safety of power equipment and affect the safety of system operation. Analyzing the fault signal and detecting the arc-flash ground fault in the distribution network is conducive to realizing the online detection of the arc-fla...

AI Technical Summary

Problems solved by technology

[0005] The present invention mainly aims at problems such as easy misjudgment or inability to identify arc ground faults in existing arc light ground fault detection methods, and introduces an atomic decomposition method to effectively detect arc light ground faults

The atomic decomposition method is a new method for analyzing nonlinear and non-stationary signals. It overcomes the shortcomings of traditional linear methods that cannot analyze non-stationary signals, and does not have the shortcomings of traditional methods such as wavelet.

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