Transformer DC magnetic bias suppression method based on multi-soil model

Abstract

The invention discloses a transformer DC magnetic bias suppression method based on a multi-soil model. The method comprises the steps: establishing a rectangular coordinate system model according to the geographic position of each station in the research area; selecting a reasonable number of measurement points by adopting a clustering analysis method in combination with the terrain and landform in the region; actually measuring the soil resistivity at each measurement point to obtain a plurality of equivalent soil models; respectively calculating the ground potential distribution of each station in the region when the DC grounding electrode operates in a single pole mode under each soil model, performing comprehensive weighting on different ground potentials obtained under various soil models by utilizing a weight coefficient matrix to obtain the ground potential of each station based on the multiple soil models, and calculating the DC magnetic bias of each transformer on the basis. The transformer DC magnetic bias suppression method based on the multiple soil models has the advantages that the soil models are closer to the actual situation, ground potential calculation is more accurate and the like, and can provide a more accurate ground potential distribution result for calculation of magnetic bias current in transformer DC magnetic bias suppression research.

Description

technical field [0001] The invention relates to a multi-soil model-based method for suppressing direct current magnetic bias of a transformer, which belongs to the technical field of electric power systems. Background technique [0002] UHV DC transmission has the advantages of large capacity, long distance, and low loss. More and more DC transmission lines have been put into operation in recent years. When the DC system is being debugged, overhauled or fails, the operation mode of unipolar-earth loop will appear, and a huge DC ground current will be generated in the DC grounding pole, and a DC electric field will be formed around the grounding pole, resulting in different degrees of grounding in the surrounding substations. The potential rises, and then a bias current is generated in the neutral point grounding system of the main transformer. [0003] At present, in the current DC bias suppression methods of transformers, the literature on DC bias research basically adopts...

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Problems solved by technology

For a study area of ​​hundreds or even hundreds of kilometers, it is difficult for one soil model to accurately simulate the actual soil conditions at each site, especially for areas with complex and diverse topography and landforms, one soil model cannot take into account different soil conditions. The transformer DC bias determined by this has a large error, which brings interference to the transformer DC bias suppression

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