多端直流异步联网对区域电网灾变恢复的支撑

摘要

A system model is established for asynchronous interconnection between the two-terminal VSC DC system and the AC grid.This article presents a strategy for the support of load recovery power by the multiple-terminal DC grid after a catastrophe occurs in the main grid.The support power is constrained by grid transmission capacity of non-faulty regions,power receiving capacity of the faulty grid,overload capacity of the DC line and transmission capacity of the converter station.Under these constraints,this article presents the maximum transmission capacity of DC power support,so as to ensure power restoration of main loads of the main grid as soon as possible and accelerate the process of catastrophe recovery of the faulty grid.Finally,simulation results verify the feasibility of the proposed strategy of support for catastrophe recovery of regional grid from VSC-MTDC.%建立了双端柔性直流输电系统与交流电网异步联网的系统模型,提出了交流主网发生灾变事故后,多端直流电网对其进行负荷恢复功率支撑的策略.支撑功率受到了非故障区域电网输送容量,故障电网的可受电能力,直流线路过负荷能力,换流站的输送容量等限制条件的影响.在这些约束条件下,提出了直流功率支援的最大可输送容量,以保证主网重要负荷尽快恢复供电,加速故障电网的灾变恢复过程.通过仿真验证了提出的多端直流异步联网对区域电网灾变恢复的支撑策略的可行性.