一种新型的微网自适应过流保护方法

微网灵活的运行模式给保护带来了严峻的挑战,对此提出了一种新型的微网自适应过流保护方法。以微网三处典型的故障为案例,从并网和离网角度剖析了微网自适应保护应具备的功能。以此为基础,给出了微网自适应保护方案并阐述了集中式微网保护的主从工作机制;提出了三段式自适应保护的过电流整定算法,设计了故障识别流程;基于分析传统过电流保护时限配合在微网保护中存在的弊端,提出了微网自适应保护在并网和孤岛时的动作时限优化方案,结合案例分析了其优点。理论和案例分析表明,所提自适应保护方法能够快速可靠地识别故障区域,满足微网对保护的要求。

A novel adaptive overcurrent protection method for microgrid

The flexible operation mode of microgrid poses a serious challenge to the protection, so this paper proposes a novel current protection mehtod for microgrid. It takes three typical faults as case study, and analyses the function of adaptive protection in connected mode and islanded mode. Based on it, a new protection scheme for microgrid is presented, and the master-slave working mechanism of the centralized protection of microgrid is also illustrated. At the same time, this paper proposes the overcurrent setting algorithm of three zones adaptive protection and designs the flow chart of fault identification. Based on the analysis of the drawbacks of the traditional overcurrent protection time limit coordination, an optimization scheme about the operation time limit in connected mode and islanded mode is also presented, and the advantages are analyzed through the cases. The theory and cases show that the adaptive protection method can identify the fault zone rapidly and reliably, meeting the need of microgrid.