柔性直流分区技术在多直流馈入的受端电网中的应用研究

多直流馈入的受端电网由于多直流落点受端系统的交直流相互作用复杂、直流馈入功率大,存在着交流故障引起多条直流同时发生换相失败的风险、区域间潮流交换困难、短路电流水平超标等问题.柔性直流输电以其快速灵活的调节功率、不增加系统短路容量等优越特性,在远距离大容量输电、异步联网等方面获得了广泛的应用.利用柔性直流输电的技术优势来...

Study on Application of Flexible Direct-current Segmentation Technology in Multi in-feed DC Receiving-end Power Network

The multi infeed DC receiving?end power network has such problems as simultaneous commuta?tion failure by AC fault,difficulty of inter?regional power flow exchange short circuit level beyond standard due to complicated interaction of AC and DC and high DC infeed power.While,the flexible DC transmis?sion has found wide application in such aspects as long?distance and large?capacity power transmission as well asynchronous networking due to its superiority such as fast and flexible regulation power without in?creasing short circuit capacity of the system.Use of technical superiority of flexible DC transmission for power network segmentation can not only reduce or even eliminate the coupling between AC and DC system and between DC and DC system during the C fault,but also provide reactive power support to the system and reduce the safe stability problem due to mutual influence between AC and DC system.In this paper,such indices as short?circuit current margin,multi infeed short?circuit ratio,proportion of short circuit faults leading to commutation failures of direct?current system and proportion of direct?current power loss caused by specific short circuit fault are introduced to evaluate current receiving?end power system repre?sented by Jiangsu power system.By comparing these indices with the application of flexible DC segmenta?tion technology,safety and stability of the system have been significantly improved.