Method for determining maximum field intensity of intermediate joint for medium-low-voltage direct-current XLPE cable

Abstract

The invention discloses a method for determining the maximum field intensity of an intermediate joint for a medium-low-voltage direct-current XLPE cable. The method comprises the following steps: firstly, collecting the structure and operating parameters of the joint; determining characteristic parameters in a relational expression that the conductivity of the main insulation material and the joint reinforced insulation material of the used cable changes along with the temperature and the field intensity through a direct current conductivity test; then calculating the temperature and the fieldintensity of the main insulation part of the cable and the enhanced insulation part of the joint so as to determine the conductivity of the two insulation materials, and finally solving the maximum field intensity value in the joint; according to the method, complex simulation modeling is avoided, and the calculation time is saved; conductivity characteristic parameters are easy to obtain; a powerful reference is provided for determination of current-carrying capacity and operation voltage in engineering of transforming an XLPE cable line from alternating current to direct current, and the method has important significance for enhancing safety and reliability of a power grid.

Description

technical field [0001] The invention relates to a simplified method for calculating the maximum field strength of a cable joint, in particular to a simplified calculation method for the maximum field strength of an intermediate joint for medium and low voltage DC XLPE cables. Background technique [0002] With the advancement of my country's urbanization and the development of renewable energy, DC cables play an increasingly important role in power systems. Compared with AC cables, DC cables have the advantages of less loss, higher insulation strength, longer power transmission distance, and lighter weight. When the load demand in the city center continues to grow, if the cable lines are expanded or newly added in the urban area, it will be subject to factors such as long construction period, large capital expenditure, and limited space for urban construction planning. Therefore, it is necessary to fully tap the potential transmission of existing cable lines Capacity is esp...

AI Technical Summary

Problems solved by technology

In the actual application of this method, due to the three-dimensional characteristics of the joint structure, the preliminary modeling is more complicated; when setting the boundary conditions, it is necessary to have a certain understanding of electromagnetic fields and finite element related knowledge, which is difficult to master; and the electric-thermal coupling analysis High demands on researchers and computer configurations, and often time-consuming iterative process

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