交流大跨越线路改直流运行关键技术的研究及实践  

The Research and Implementation of Key Technologies for Converting AC Large Crossing Transmission Line to DC Operation

作　　者：张瑞永 奚海波 吴锁平 贾振宏 李金科 ZHANG Ruiyong;XI Haibo;WU Suoping;JIA Zhenhong;LI Jinke(China Energy Engineering Group,Jiangsu Power Design Institute Co.,Ltd.,Nanjing 211102,China)

机构地区：[1]中国能源建设集团江苏省电力设计院有限公司,南京211102

出　　处：《电力学报》2024年第3期255-263,共9页Journal of Electric Power

基　　金：江苏省自然科学基金(青年基金项目BK20210048);中国电力工程顾问集团公司科技项目(DG2-D04-2023);中国能源建设集团江苏省电力设计院有限公司科技项目(32-JK-2022-013)。

摘　　要：通过将交流大跨越线路改为直流运行,构建具有“内嵌式”直流系统定位和“扩展背靠背”的功能定位的系统网架,提升现有输电通道的输电能量密度,实现送受端220 kV分区柔性联络。针对镇江五峰山大跨越线路不改变杆塔结构的要求,根据绝缘子的爬距确定满足污秽要求的直流电压,并进行操作过电压、雷电过电压、直流跳闸率和通航高度的校核,同时进行了线路增容改造及导线排列方式优化。五峰山“交改直”改造工程的运行情况表明,将220 kV交流大跨越线路改为±200 kV直流运行后,其输送容量可达到原交流线路的4.8倍,有效解决了过江输电瓶颈问题,挖掘了长江大跨越线路的输电潜能。这一创新性示范方案为解决电网发展难题提供了有益的方案,尤其对于国内新增通道代价高昂或实施困难的场景具有重要意义。In this research,we propose a transformative solution to improve power transmission in the Zhenjiang Wufengshan area.By converting the existing AC large crossing transmission line to a DC system with embed-ded positioning and extended back-to-back functionality,we can significantly increase the power density of the transmission corridor.Without altering the tower structures,we determine the required voltage for DC operation base on the insulator’s creepage distance,ensuring compliance with pollution requirements.We validate the pro-posed approach through various calculations,including overvoltage operation,lightning overvoltage,DC circuit breaker trip rate,and navigational clearance.The operation of the Wufengshan“traffic to direct”renovation project shows that by implementing capacity expansion and optimizing conductor configuration,converting the 220 kV AC large crossing transmission line to±200 kV DC operation can achieve a transmission capacity 4.8 times higher than that of an AC line.This solution effectively addresses the current bottleneck in cross-river power transmission and harnesses the untapped transmission potential of the Yangtze River.It provides an inno-vative and valuable demonstration scheme for overcoming challenges in power grid development,particularly in scenarios where establishing new transmission channels is costly or difficult.

关 键 词：输电线路 大跨越 交流线路改直流运行 “嵌入式”直流 增容改造 

分 类 号：TM751[电气工程—电力系统及自动化]