A Calculation Method of Converter Transformer-Heat Coupling Field Based on Improved Meshless Method

Abstract

The present invention claims to protect a calculation method of converter-transformation-thermal coupling field based on the improved gridless method, including determining the mathematical nonlinear model of UHV converter-rheology insulating oil-paper material, and two-dimensional axisymmetric nonlinear electrical-thermal coupling Field calculation model; the improved gridless method is used to calculate the coupled field of converter, electricity and heat. The model layout is adjusted according to the size, and the converter and temperature fields are calculated separately. The size of the subdomain avoids its crossing with the global boundary, and the collocation method is used for calculation on the global boundary. In the coupling data transmission of electric field and temperature field, when it is necessary to calculate the thermal load of the temperature field, the Gaussian integral point of the local subdomain of the temperature field is searched according to the geometric coordinates in the local subdomain of the electric field calculation model, and the thermal load is obtained by interpolation according to the number of nodes in the local subdomain The load value updates the material properties of the electric field, and realizes the iterative calculation and acquisition of the distribution law of the converter-transformation-thermal coupling field. The invention improves calculation time and accuracy.

Description

technical field [0001] The invention belongs to the technical field of insulation level evaluation of UHV equipment, and in particular relates to a calculation method for UHV converter-transformation-thermal coupling field. Background technique [0002] Due to the uneven distribution of domestic resources, UHV is being vigorously constructed, which is an important strategy in the 13th Five-Year Plan, especially with the proposal of the Energy Internet construction strategy, the safety and reliability of UHV systems has received a lot of attention. [0003] As the key equipment of the UHV system, the reliability of the UHV converter directly determines the safe operation of the system. However, the key technology of the converter still relies on foreign technology, mainly because of the insulation problem. Because the converter rheology insulation components have AC-DC composite action conditions, and the conductivity of oil and oil paper is greatly affected by temperature, t...

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Problems solved by technology

Both Harbin University of Science and Technology and Xi'an Jiaotong University have analyzed the distribution of the electric field under AC and DC conditions, while the North China Electric Power University has considered the nonlinearity of the electric field, and the existing design does not consider the influence of the actual temperature distribution on the electric field, but Select the temperature corresponding to the most severe case of insulation and the corresponding electrical parameters of oil and oil-paper, and use this as a basis to design converter rheological insulation components, and there is a problem of excessive insulation margin design

[0004] Therefore, the inventors found that domestic and foreign studies have seldom studied the problem of converter-thermal coupling, and due to the large size difference of converter-rheological insulation components, the use of grid-type analysis methods will have a large number of grids and reduce computational efficiency. Low-level problems, and there are also mapping accuracy problems in the coupling data transmission of electric field and temperature field, which need to be improved in these aspects

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