Effect Of Weld Defects On The Tubular Bus-bar Conductivity And Heat Generation

With the improvement of the national economy technical level and the power grid expanding, tube bus has been widely used in the power grid construction. Tube Bus welding quality is a key factor of overall performance. In this paper, according to tube bus welds porosity, incomplete penetration, cracks and other weld defects, as 220 kV transformer substation commonly used?150×7 tube bus for the study. Using of X-ray digital imaging system to detect the experimental samples to determine the type and macroscopic dimensions of weld defects. Through the flow experiments, using of infrared thermal imaging technology to study the different types of weld defects impact on tube bus heat generation.Firstly, according to the basic parameters and characteristics of 220 kV tube bus, introduced tube bus welding technology and welding characteristics, analyzed the basic characteristics and causes of a variety of common weld defects. Secondly, made a detection test on experimental samples by using of X-ray digital imaging system, determined the X-ray detect parameters and irradiation method. According to the measurement of the defect size on software imaging, derived calculation formulas of weld defects actual size. Meanwhile, according to the principle of electromagnetic induction, loaded current for tube bus test sample by using of up-flow current transformer, and using the Fluke thermal imager detect temperature changes around the weld. Analyzed the temperature difference around the weld of common weld defects experimental samples with different load currents, and compared with normal experimental sample data, got a different degree of influence and variation of weld defects on tube bus heat generation. Finally, using the finite element method calculate the tube bus heat losses of two-dimensional temperature field, analyzed impact of environmental conditions on the tube bus temperature field, and obtained the tube bus dimensional temperature field distribution curves; Established different weld defects tube bus dimensional finite element model to analyze the weld defects impact of tube bus heat generation. and compared with experimental results to verify the reliability of the simulation results, which provides an important reference and methods for tube bus weld quality live detection.