基于幅相关系的有源配电网多端差动保护方案

Multi-terminal differential protection scheme for active distribution network based on amplitude-phase relationship

分布电源的大量接入使配电网从传统单向潮流的辐射状网络逐步转变为双向潮流的多端电源供电的配电网,出现了以T型接线为代表的多段线路。文章从多种类型分布式电源的故障特性入手,分析短路故障下有源配电网的多端电流的幅相关系,提出基于多端电流幅相关系的差动保护方案。保护方案包括启动判据和复合动作判据,启动判据兼具区分部分区外故障的作用,动作判据为两个独立判据的逻辑与,以保证可靠动作和避免误动。此外,文章讨论基于光纤通道通信的配电网多端信息同步技术,用以实现多端信息同步传输。PSCAD/EMTDC的仿真结果表明所提方案的可靠性和速动性。

The large amount of access to the distributed power supply has gradually transformed the distribution network from the traditional unidirectional tidal radial network to the two-way tidal multi-terminal power supply distribution network,and a multi-segment line represented by T-type wiring has appeared.Based on the fault characteristics of various types of distributed power supplies,this paper analyzes the amplitude-phase relationship of multi-terminal currents in active distribution networks under short-circuit faults,and proposes a differential protection scheme based on multi-terminal current amplitude-phase relationship.The protection scheme includes the initiation criterion and the composite action criterion.The initiation criterion has the function of distinguishing the faults outside the zone.The action criterion is the logical sum of two independent criteria to ensure reliable action and avoid maloperation.In addition,this paper discusses multi-terminal information synchronization technology based on fiber channel communication for distribution network to realize multi-terminal information synchronization transmission.The simulation results of PSCAD/EMTDC show the reliability and quickness of the proposed scheme.