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This post was last edited by Yu Qin on 2020-2-29 23:35. In long-distance power transmission, power transmission and transformation equipment is subject to various types of overvoltages. At lower transmission voltages, the main factor determining the insulation level of the power transmission and transformation system is lightning overvoltage, and protection can be provided using simple spark gap arresters. Later, people switched to nonlinear resistors such as series silicon carbide, leading to the development of valve-type surge arresters that can limit both distant lightning overvoltages and near lightning overvoltages. As transmission voltages increase to higher, ultra-high, and extra-high levels, lightning overvoltages do not rise in proportion; instead, switching overvoltages gradually become the main factor determining the insulation level of power transmission and transformation systems. Therefore, magnetic blowout valve arresters and current-limiting magnetic blowout valve arresters were developed accordingly to achieve the capability of limiting lightning overvoltages and switching overvoltages. In the early 1970s, scientists focused on research into the application of zinc oxide nonlinear resistive elements in power surge arresters. Due to the excellent nonlinear characteristics, superior current-carrying capacity, and other advantages of zinc oxide’s nonlinear resistance, zinc oxide arresters have seen rapid development in recent years. Products in the entire range of 3.3–500 kV have already been manufactured, and efforts are underway to develop them for even higher voltage levels. The development of zinc oxide arresters has become the main trend in arrester technology. The development of lightning arresters for electrical applications can be summarized in four stages: the first is the spark gap ； Second, silicon carbide valve-type latticed window ； Third is, silicon carbide current-limiting arresters ； Fourth, zinc oxide arresters. (Original content by Junhe Electronics; please indicate the source when reproducing it)