并联电抗器在超(特)高压电网中应用及发展

研究了超（特）高压输电线路在长线电容效应、不对称接地和突然甩负荷等各种工况下工频过电压的产生．提出了采用并联电抗器进行无功补偿限制工频电压升高的措施。分析了并联电抗器在超（特）高压输电线路单端供电与双端电源供电情况下抑制过电压的作用。分析比较了裂心式、磁饱和式及变压器式3种超（特）高压可控并联电抗器的基本工作原理、主要功能和特性．指出裂心式可控电抗器具有非线性伏安特性，兼具大幅度限制操作过电压功能：磁饱和式电抗器的伏安特性与普通电抗器相近，结构简单、控制方便，具有优良的技术经济综合指标：变压器式可控电抗器与磁饱和式可控电抗器相比。谐波电流更小、响应速度更快、功率损耗更小。同时指出了特高压并联电抗器与超高压并联电抗器相比的特殊性。

Application and development of shunt reactors in EHV & UHV transmission lines

The power frequency over-voltage of EHV(Extra High Voltage) & UHV(Ultra High Voltage)power transmission lines in three operating conditions,i.e.capacity effect of unloaded line,unsymmetrical faults and load shedding is analyzed,and measures are put forward to limit the power frequency voltage rising by using the shunt reactor to compensate the reactive power.The function of the shunt reactor to restrain power frequency over-voltage is analyzed theoretically for EHV & UHV transmission lines with single power supply or double power supplies.Basic principles,main functions and characteristics of three high-voltage controllable shunt reactor types are analyzed and compared,i.e.split core type,magnetic valve type and transformer type.The volt-ampere characteristic of the split core type controllable shunt reactor is nonlinear,and the switching over voltage can be restrained greatly.The volt-ampere characteristic of the magnetic valve type controlled shunt reactor is similar to the common reactor,which is simple and convenient for control,with satisfying technology and economy index.Compared with the magnetic valve type controlled shunt reactor,the transformer type controlled shunt reactor is superior in its smaller harmonic current,faster respond speed and less power loss.Based on the comparison of shunt reactor used in EHV network and UHV network,the particularity of UHV shunt reactor is discussed.