AC/DC waveform extraction method, device and equipment and a storage medium

Abstract

The invention relates to the technical field of power system grounding safety, and discloses an AC / DC waveform extraction method, device and equipment and a storage medium, and the method comprises the steps: separating the waveform of an AC / DC part in a DC bias current, carrying out the spectrum analysis of an AC component and a DC component, and obtaining the harmonic content of each component. The analysis of the proportion relation of the current contents with different frequencies is beneficial to the research of the distribution rule of the direct-current magnetic bias of the transformer and the elimination of the adverse effect of the direct-current magnetic bias on the alternating-current power grid. The method comprises the following steps: recording a grounding current waveform of a neutral point of a transformer through a data recorder; acquiring the number of sampling points in each period under the power frequency of 50Hz according to the sampling frequency; according to the grounding current waveform, the sampling frequency and the number of the sampling points in each period, calculating an average value of data points in each period under the power frequency of 50Hz, and obtaining a DC offset waveform; and subtracting the DC bias waveform from the grounding current waveform to obtain an AC current waveform.

Description

Technical field [0001] The present invention relates to a power system grounding security technology, particularly to a DC waveform extracting method, apparatus, device, and a storage medium. Background technique [0002] With the rapid development of urban rail transit, the DC traction power supply system of stray current problem of growing emissions in recent years, some areas power supply companies will also find stray current transformer neutral invasion along the subway network by grounding power system , it will lead around the substation DC bias magnetic phenomenon to varying degrees. Transformer DC bias phenomenon will cause increased noise transformer adverse impact on nearby residents, while causing no power loss and excitation current harmonic content increases and other issues, and even cause structural abnormalities equipment, equipment and a serious threat to security and stability operation. Real-time recording wave transformer neutral grounding current Extraction ...

AI Technical Summary

Problems solved by technology

[0003] At present, the existing technology is mainly aimed at the measurement, recording and detection of DC current at the neutral point of the substation, and there is no related technology for the extraction method of AC and DC waveforms in the neutral point grounding current of the substation.

Moreover, the real-time wave recording of the neutral point grounding current of the transformer in the field requires a large amount of data storage, and it is very difficult to extract the proportion of AC and DC content. Effective AC and DC waveform information cannot be obtained, which is not conducive to the analysis of the DC bias magnetic distribution of the transformer.

In addition, the sampling rate of the existing DC bias current at the neutral point is too low, only one data per second, and the average value of the DC component and the effective value of the AC component are given, without the actual waveform, which makes it impossible to analyze the waveform. Such as spectrum analysis and harmonic analysis are not good for understanding the source of the DC bias component and the selection of the filtering scheme

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