Converter transformer electric-thermal coupling field calculation method based on improved meshless method

Abstract

The invention provides a converter transformer electric-thermal coupling field calculation method based on an improved meshless method. The method includes the steps that a mathematical nonlinear model of extreme high voltage converter transformer insulating oiled paper materials is determined, and a two-dimensional axial symmetric nonlinear electric-thermal coupling field calculation model is determined; the improved meshless method is used for calculating a converter transformer electric-thermal coupling field, modes of model point distribution are adjusted through self-adaption according tosizes, and the electric field and temperature field of a converter transformer are calculated respectively; the sizes of local sub-fields are adjusted in the vicinity of calculation boundary areas toprevent the local sub-fields from intersecting with global boundaries, and the point distribution method is used for calculation on the global boundaries; in the coupling data transmission process between the electric field and the temperature field, when a thermal load of the temperature field needs to be calculated, the gauss integral points of the local sub-fields of the temperature field andthe local sub-fields in an electric field calculation model are searched for according to geometric coordinates, and the thermal load is obtained according to the node number interpolations in the local sub-fields; electric field material properties are updated, and the iterative calculation and the distribution law acquisition of the converter transformer electric-thermal coupling field are obtained. The method 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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