There are various structures and types of trolley lines, from the initial angle iron trolley line, channel steel trolley line, (high power consumption, poor safety) to the present H-type unipolar safety trolley line (high temperature resistant Flame retardant trolley line), tubular safety trolley line, cable trolley line (explosion-proof trolley line) seamless trolley line (sliding line with never-ending power, small current without joints), M for automatic lines Type/U-shaped trolley lines, high temperature resistant and high current steel body trolley lines, and high-tech non-contact induction trolley lines,