Research on structural type of two-way connection fittings based on valve hall

Abstract

Based on the research on the structural type of valve hall two-way connection fittings, with the sustained and rapid economic growth, the power demand of various industries increases. While accelerating the construction of UHV backbone power grid, improving the transmission capacity and transmission quality of the existing power grid has become a top priority. In ± 800kV UHV DC transmission project, the rated current is up to 6250A, and the current carrying capacity of valve hall fittings in converter station increases accordingly, which puts forward higher requirements for heat resistance and reliability of fittings. Therefore, it is very necessary to study the operation reliability of valve hall fittings in converter station. In this paper, two structural types of two-way connection fittings are analyzed. The temperature field of two-way connection fittings is simulated by using the electric thermal coupling finite element analysis method. At the same time, the high current temperature rise test is carried out, and the temperature at the key position of two-way fittings is measured by thermocouple. The high current temperature rise test and simulation results show that when 6250A current is applied, there is uneven shunting between the two specimens. Under the condition of meeting the temperature rise limit, the flow through of aluminum strand connection mode is more uniform than that of aluminum row connection mode. The test results are consistent with the simulation results, which provides a reference for the subsequent design of valve hall fittings.