特高压直流工程的融冰控制保护策略及试验分析

Analysis of Control and Protection Strategy and Test for De-icing mode in UHVDC Project

极端气候条件和输送功率的限制使得直流电流无法满足融冰要求,导致直流输电线路形成覆冰,这将严重影响特高压直流系统的稳定运行。本文结合酒湖直流工程的融冰功能,阐述了特高压直流输电工程中循环阻冰模式和并联融冰模式运行的主接线拓扑结构与特点,提出了循环阻冰模式下两极联跳的策略和并联融冰模式下直流控制保护功能的修改方案。通过RTDS闭环实时数字仿真验证了融冰功能的可行性和有效性,可为特高压直流输电工程融冰运行方式的直流控制保护系统设计提供参考。

Because of extreme weather conditions and the limitation of the transmission power, the DC current can not meet the requirement of de-icing. And it will lead to the formation of the DC transmission line icing, affecting the stability of the UHVDC system seriously. Combined with the de-icing function in Jiuquan-Hunan UHVDC project, the main connection topological structure and characteristics of the round resistance ice mode and hybrid de-icing mode for the UHVDC project is described in this paper, and then the strategy of bipolar synchronous tripping in round resistance ice mode and the modified scheme of UHVDC control and protection function in hybrid de-icing mode are proposed. At last, the feasibility and effectiveness of the de-icing function are verified by RTDS closed loop real-time digital simulation. Reference is provided for the design of UHVDC control and protection system for the de-icing operation mode.