1000kV交流输电线路的工频暂态过电压研究

以国家电网公司已进行了前期论证工作的晋东南-南阳-荆门单回百万伏级输变电示范工程为背景,研究了其在各种工况下的工频电压升高,包括空载线路电容效应、不对称故障及甩负荷三种工况,提出了包括采用高压电抗器进行无功补偿等限制工频电压升高的措施.仿真计算表明,空载线路电容效应引起的工频电压升高最大值为1.04pu,单相接地故障引起的工频电压升高最大值为1.31pu,甩负荷引起的工频电压升高最大值为1.20pu.对于甩负荷和不对称接地故障这两种工况,并联高压电抗器装设在线路末端时抑制工频过电压的效果比装设在首端或装设在两端时要好.

Research on Power Frequency Transient Overvoltage in 1000kV UHV AC Transmission Line

Against the background of a single circuit UHV power transmission project in one million voltage from Jincheng to Jingzhou via Nanyang that is reasoned by State Power Grid Corp. of China, its power frequency overvoltages in three operating conditions, i.e., capacity effect of unloaded line, unsymmetrical faults and load shedding, are researched, and the measures to eliminate power frequency voltage rising such as using high voltage reactor to compensate reactive power are put forward. Simulation results show that the maximum power frequency voltage rising caused by capacity effect in unloaded line, single-phase earth fault and load shedding are 1.04 per unit, 1.31 per unit and 1.20 per unit respectively. Under load shedding and unsymmetrical earth fault, the effect of eliminating power frequency voltage rising is better when parallel high voltage reactor is installed at the receiving end of transmission line but not at the sending end or at both ends.