摘要
特高压直流输电系统双极闭锁故障时会导致输电断面上大量功率的瞬间缺失,从而使部分联络线严重过负荷。针对该问题,提出了在特定线路装设移相变压器来将过载联络线的部分潮流转移到其他轻载联络线上,从而减少了直流线路故障时所需切除的负荷量,提高了电网的供电可靠性。通过讨论移相器的数量和选址问题,总结出了不同情况下的决策方法,并以一个总负荷约为22 000 MW的大系统为例,确定了移相器的类型和具体模型,并推导和计算了移相器的相关参数,利用PSASP平台仿真出了不同移相角时各联络线的潮流。研究结果表明,移相器能够实现联络线之间输送功率的转移,充分利用了输电断面上联络线的输电能力,从而能够改善特高压直流闭锁故障带来的输电断面联络线过载问题。
The bipolar block faults of UHVDC transmission system can lead to instantaneous large power deficiency in the transmission sec-tion, which make part of the tie-lines heavily overload. Aiming at this problem, installing phase-shifting transformers in particular transmis-sion lines to transfer part of power flow from over-load tie-lines to other light-load tie-lines was proposed, which can reduce the amount of loadthat needs to be shed and improve the power supply reliability of the power grid when the bipolar block faults take place. Through discussingthe quantity and location problem of phase-shifting transformers, the decision-making methods under different circumstances were summarizedand a large scale power system whose total load is about 22 000 MW was taken as an example. The type and concrete model of phase-shiftingtransformer were decided and the relevant parametem of the phase-shlfting transformer were derived and calculated. The power flow of eachtie-line at different phase-shifting angles was simulated using PSASP. The results indicate that phase-shifting transformers can realize powerflow transfer between tie-lines and make full use of the transmission capability of the tie-lines on the transmission section, which can reducethe tie-line overload caused by bipolar block faults of UHVDC transmission system.
出处
《机电工程》
CAS
2016年第12期1496-1500,共5页
Journal of Mechanical & Electrical Engineering
关键词
移相变压器
特高压直流双极闭锁
联络线
潮流转移
电力系统分析综合程序
phase-shifting transformer（PST）
bipolar block faults in UHVDC
tie-line
power flow transfer
power system analysis softwarepackage （ PSASP ）
