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In recent years, bird droppings flashover faults frequently occur on transmission lines. Based on the existing conditions of the laboratory, this paper explores the flashover mechanism of 110 kV bird droppings. A new type of bird droppings propulsion device was designed and developed, and the process of bird droppings falling in the natural state was simulated without voltage. According to several typical forms of bird droppings, the main findings are ① the bird droppings connected to the two poles are the most serious short circuit situation; ② the bird droppings flashover fault of the 110 kV line is actually a single-phase grounding fault of the line through a resistance, and the grounding resistance is between 20 and 300 kΩ; and ③ the conductivity is the most sensitive factor affecting bird droppings flashover. [ABSTRACT FROM AUTHOR]

During the opening and closing process of the contact, it will undergo repeated arc ablation and wear. After each ablation and wear, the composition, performance, and shape of the contact surface constantly change, leading to cracks, slag drop, melting, evaporation, and other phenomena on the contact surface, ultimately causing the contact to fail, resulting in the switch not being able to open and close normally. In order to study the failure mechanism of arc contacts caused by arc erosion after breaking short-circuit current, a pair of arc contacts for the cumulative breaking short circuit current test was selected as the research object. The metallographic, microscopic morphology, and energy spectrum analysis of the arc contacts were conducted, and the analysis results were compared with the new arc contacts to reveal the evolution and development process of arc contacts from cumulative arc erosion to failure during breaking. [ABSTRACT FROM AUTHOR]

In this paper, pulse laser cleaning and angle grinder polishing were used to clean the surface rust of carbon steel, and the cleaning effects of different cleaning methods for carbon steel surface rust were studied. The change of the micro-region morphology and element composition of the cleaned surface was analyzed. Comparative experiments were conducted on the corrosion resistance and paint anticorrosion ability of cleaned metal surfaces. Through comparison and analysis, the use of laser cleaning technology can improve the surface cleanliness and corrosion resistance of metals, reduce maintenance times, and extend service life. Laser cleaning machines with a power of 100 W or above can effectively perform precision cleaning and can be widely promoted in the field of power systems. [ABSTRACT FROM AUTHOR]