The Research On Restrain Strategy For Over-voltage Of UHV Transmission Line

China's development is imperative,ultra-highvoltage grid transmission line overvoltage is limited internal development UHV transmission technology process must solve the problem. Internal overvoltage the highest multiples and system running voltage amplitude connected, so the higher voltage level, the more serious the overvoltage problems. In UHV long-distance transmission system, industrial frequency voltage rise decided electrical equipment insulation level. China will UHV grid location for the bone grids, and operating over-voltage is decided according to power system one of the insulation level.This paper mainly discusses no-load long lines of power frequency capacitor effect caused by high voltage parallel should be elevated to limit and reactor reactor to let rise of compensation position to be in the end of lines, end compensation effect is best. Power system is dynamic, light load operation conditions, the line voltage on the high side, heavy load operation conditions, low voltage controlled reactor, if use, can replace fixed reactor both industrial frequency overvoltage restrictions and reactive power regulation. This article mainly discuss no-load UHV transmission lines in EHV 60%,80% and 90% three compensation degree circumstances limit effect, and agreed to compensate degrees cases in the first terminal, compared the positions, end etc compensation restrictions effect is. Consider racing circuit happened single-phase short circuit fault, will be in grounded potential power flow produce unfavorable point, so should be in reclosing controlled reactor limit on adding small neutral circuit reactance. If the racing line parallel operation, besides considering industrial frequency overvoltage outside, still should plan and amplitude higher close brake overvoltage, generally choose close brake resistance restriction but prepare for electric power system is complicated and hard to satisfy single level off the resistance power system, this paper use multilevel off need overvoltage. Off resistance limit finally, using the ATP- EMTP the rationality of the above measures simulation analysis and conclusions. Proposed in this foundation the limit of ultra-high voltage internal overvoltage reasonable measures.