“嵌入式”直流技术在省级输电网中的规划及应用

江苏电网作为典型的省级输电网,面临着大规模新能源接入带来的能源转型压力和挑战,需要从“源网荷储”等各方面进行转型升级。本文通过对负荷、电源、网架结构等江苏能源电力发展格局的分析,总结了江苏电网面临的例如重要输电断面输电能力不足等挑战。结合新能源大规模发展及江苏输电网结构特点,重点分析了“十四五”及远景江苏输电网过江断面输电能力需求,提出了送、受两端均位于江苏交流电网内部且分布长江两侧的“嵌入式”直流技术。相比较于传统的互联方式建设的远距离、大容量直流输电技术,本文提出的 “嵌入式”直流输电技术通常利用现有架空输电线路或现有/预留交流电缆通道,构建江苏省内交直流混联电网,在有限输电走廊空间内可大幅提高电网关键断面的输电能力,挖掘现有电网的供电潜力,满足江苏电网发展的需求。

Planning and application of embedded DC transmission technology in the provincial transmission power grid

Jiangsu power system as the typical provincial receiving-end power system is faced with the pressures and challenges induced from system-integration of rapid developments of renewable energy during the energy transition period, which needs to be upgraded in "source-network-load-storage" and other aspects. Through the analysis of energy development from "source-network-load-storage " aspects in Jiangsu, challenges faced by Jiangsu power system such as insufficient transfer abilities of important transmission sections are put forward. Considering the large-scale integrated renewable energy and structure characteristics of Jiangsu transmission power grid, transmission-capacity demands of the critical north-to-south Yangtze-river-crossing section during the "14th Five-Year Plan" and future are emphatically analyzed. Afterwards "embedded" DC transmission technology that both the transmission- and receiving-ends are located in Jiangsu AC network and distributed on both sides of the Yangtze River are proposed. Comparing with the traditional long-distance and high-capacity DC transmission technology constructed under the interconnection mode, the "embedded" DC transmission technology proposed in this paper usually uses the existing overhead transmission lines or existing/reserved AC cable channels to construct the AC-DC hybrid power grid in Jiangsu Province, greatly improving transmission capacities of important sections with limited transmission corridor spaces and power supply potential abilities of the existing power system to satisfy the development demands of Jiangsu power system.