特高压交直流耦合电网主变充电对特高压直流运行影响研究

Study on the Influence of Transformer Charging on UHVDC Operation in UHVAC and UHVDC Coupled Power Grid

随着特高压交直流工程大规模建设和交直流耦合程度的加深,多直流馈入受端电网主变充电对直流输电及受端电网运行具有一定影响。根据规划2017年淮沪特高压交流南半环重要枢纽苏州站将投运,为了研究特高压交流苏州站启动调试期间充电对锦苏直流运行的影响,在RTDS中搭建了锦苏直流和淮沪特高压交流及周边等值交流电网,采用与锦苏直流输电工程在控制保护功能和故障下的暂态响应等方面特性一致的特高压直流控保真型装置与RTDS构成闭环仿真平台,对锦苏直流近区空充主变以及特高压交流主变后锦苏直流运行情况进行了仿真分析。结果表明,锦苏直流近区主变充电会导致锦苏直流周期性换相失败并闭锁,但是苏州特高压交流主变空充对特高压直流运行无明显影响,所得结论对淮沪特高压交流工程启动调试具有重要参考意义。

With the increasing coupling degree of UHV AC/DC system and large-scale construction of UHV AC/DCproject,main transformer charging in multi-DC feed-in receiving end power grid has certain influence on the DCtransmission and the operation of the receiving end. According to the plan,in 2017 Suzhou station for important hubof Huaihu UHVAC southern half will be put into operation,in order to study the influence of charging on the opera-tion of Jinsu UHVDC during the commissioning of UHVAC Suzhou station,in the RTDS Jinsu UHVDC and HuaiHuUHVAC equivalent power grid is built,actual control and protection device are built to form a closed loop simulationplatform with RTDS. Its performance remains highly consistent with actual UHVDC project in protection functions,behavior under fault of AC and DC and other aspects of characteristics. The operation of JinSu UHVDC near-zonetransformer and UHVAC transformer after air-charging are simulated and analyzed. The results show,transformernear JinSu UHVDC charging will lead to cyclical commutation failure and blocking,but the Suzhou UHVAC trans-former empty charge has no significant effect on the UHVDC operation basically. The conclusion is of great reference significance for the commissioning of HuaiHu UHVAC project.