背靠背换流站核心区域设计方案分析

The Scheme Analysis of the Core Area in Back-to-Back Converter Station

为解决跨区输电以及短路电流超标问题,可考虑采取直流背靠背技术实现电网异步互联和目标网架优化。本文结合2022年投产的云霄换流站和粤中换流站工程实际,对比分析柔性直流和常规直流两种直流背靠背技术的工程特点。论文总结了两个工程核心区域的电气接线、设备选型和布置方案,并从技术方案和工程造价两方面开展对比分析。研究结果表明:在大多数异步联网场景下,常规直流背靠背技术仍然具有一定工程造价优势;但柔性直流背靠背技术在多直流馈入电网应用时可降低同时换相失败风险,具有无可替代的技术优势。本文相关研究成果可为后续背靠背直流工程设计应用提供参考。

In order to solve the problems of cross-regional transmission and short-circuit current exceedance,DC back-to-back technology can be considered to realize the asynchronous interconnection of the power grid and the optimization of the target grid.In this paper,combined with the actual engineering situation of the Yunxiao and Yuezhong converter station whitch both were put into operation in 2022,the engineering characteristics of LCC and VSC DC back-to-back technologies are compared and analyzed.This paper summarizes the electrical wiring,equipment selection and layout schemes of the two projects core area,and carries out a comparative analysis from the aspects of technical scheme and project cost.The results show that in most asynchronous networking scenarios,LCC DC back-to-back technology still has certain engineering cost advantages.However,the VSC DC back-to-back technology can reduce the risk of simultaneous commutation failure when multiple DC feeds into the power grid,and has irreplaceable technical advantages.The research results in this paper can provide a reference for the subsequent back-to-back DC engineering design application.