计及柔性直流装置的交直流配电网保护控制研究

Research on protection and control of AC/DC distribution network considering DC flexible device

交直流混合配电网可更好地接纳分布式电源和直流负荷,缓解城市电网站点走廊有限与负荷密度高的矛盾,已成为现代城市配电网的一个重要发展趋势。接入柔性环网控制装置后,配网由单端电源供电网络变为多端电源供电网络,其可靠性面临新的挑战。通过对交直流混合配电系统的故障特点进行总结,分析接入柔性直流控制装置后柔直侧及系统侧的保护影响,提出基于时序配合的智能装置协同控制架构。利用柔性电力电子器件的快速响应特性,设计柔性直流控制装置与交流保护控制装置配合的保护控制策略。在GOOSE有向节点及快速通信机制的作用下,运用保护控制协同策略进行故障定位及隔离,有效地增强了含柔性互联装置的交直流混合配电网可靠性,具有工程实用价值。

AC/DC hybrid distribution can accept distributed power supply and DC load more easily and can alleviate the contradiction between the restricted space of city grid site and the high density of load.Thus it has become an important development trend of modern city distribution network.After access to the flexible AC and DC devices,distribution network has changed to a multi terminal power network from a single terminal power network,thereby its reliability will face to new challenges.This paper summarizes the fault characteristics of AC/DC hybrid power distribution system,analyzes the influence of the flexible DC control device on the flexible side and the system side,and then proposes a cooperative control architecture of the time sequence cooperative smart device.It combines fault characteristics of AC/DC hybrid power system,uses the fast response characteristics of flexible power electronic devices,and designs the protection and control strategy of flexible DC control device and AC protective control device.By using GOOSE directed node and fast communication mechanism and applying protection and control coordination strategy for fault location and isolation,it effectively enhances the reliability of AC/DC hybrid distribution with flexible interconnection device,thus it has practical value in engineering.