Widely used in transmission and distribution lines, the effective anti-accident measures. That is, when the line failure, the relay circuit breaker tripping, the device auto-reclosing after a short time interval, so that a re-breaker. In most cases, fault lines (such as lightning, wind, etc.) is temporary, after tripping circuit breaker insulation performance (insulator and air space) can be restored, coincidence can be successful again, which increased the power supply system reliability. Limited circumstances permanent fault, automatic re-closing devices on the move after the opening relay action Zaitao to identify reasons, be excluded from the power supply. Under normal circumstances, line fault reclosing after tripping sooner, the better. Reclosing allow for the shortest time interval 0.15 to 0.5 seconds. Rated voltage lines higher insulation to the longer ionization time. Automatic reclosing the success rate structure on line, voltage levels, weather conditions, fault type, and other major changes may be. According to statistics of China's power sector, usually ranging from 60% to 90%. Another electricity sector widely used anti-accident measures are automatic standby power input, the time usually required for the 0.2 ~
0.5 seconds. It required little investment in the maintenance of normal supply substantial economic benefits.
