新型配电系统多层级交直流互联理念、关键技术与发展方向

Concept, Key Technologies and Development Direction of Multilevel AC/DC Interconnection in New Distribution System

随着“双碳”政策的推进与新型电力系统建设的深化,以分布式光伏与电动汽车为代表的新型源荷发展迅速,占比达到新高度。新型源荷功率的波动性和随机性对配电网的安全运行和灵活性提出了新的要求和挑战。针对柔性配电网建设的多样性、差异化特点,剖析了配电网各层级对交直流互联的需求,介绍了其在低压台区内实现源荷高效接入、低压台区间互联实现功率转移与故障支援、中压馈线实现供电能力与灵活性提升、区域层面实现新型源荷“大时空”匹配与区域间的互联互济4个层次的核心作用和研究进展。围绕交直流混合配电系统结构、优化规划、运行控制和故障恢复,对未来交直流混合配电系统的技术发展方向进行了展望。

With the promotion of the “carbon emission peak and carbon neutrality” policy as well as the construction of new power systems, renewable sources and novel loads, such as distributed photovoltaics and electric vehicles have developed rapidly and their proportion has reached new heights. Due to the power fluctuation and randomness, these sources and loads bring new requirements and challenges to the safe operation and flexibility of distribution networks. Aiming at the diversity and difference of flexible distribution network construction, this paper analyzes the demand for flexible interconnection at different levels of distribution network, and introduces its core role and research progress in four levels: realizing efficient integration of source and load in low-voltage station area, realizing power transfer and support between interconnected low-voltage station areas, realizing the improvement of power supply capacity and flexibility in medium-voltage line, and realizing source-load “large spatio-temporal” matching and the interconnection and mutual power support between power grids. Focusing on the structure of AC/DC hybrid distribution system, optimal planning, operation control and fault restoration, the future technical development direction of AC/DC hybrid interconnected distribution system is prospected.