有源配电网电流差动保护应用技术探讨

有源配电网具有多电源、多分段、多分支、功率双向流动、弱馈等特征,传统三段式电流保护难以保证选择性和灵敏性,需要提供新的更有效的保护方法。基于该背景,将正序故障分量电流差动保护引入到有源配电网,探讨其应用原理与实现技术。针对不同的馈线结构,给出了适应性差动保护动作判据及门槛整定原则。针对配电网线路特点,提出并实现了基于故障信息的电流数据自同步方法。根据配电自动化通信体系最新进展,探讨了基于点对点对等通信实现差动保护数据交换的通信规约。基于智能配电终端平台,开发出正序故障分量电流差动保护样机并对其进行了综合测试,测试结果验证了所提保护方案的可行性。

Study on application technology of current differential protection in active distribution network

For active distribution network, its characteristics can be described as multi-source, multi-segment, multi-branch, bidirectional power flow, bidirectional fault current, weak-infeed and so on. In this case, the selectivity and sensitivity of traditional over current protection scheme cannot be ensured. It is necessary to provide more effective protection methods. This paper introduces a current differential protection scheme based on positive sequence fault component (PSFC) into active distribution network, and discusses its application principle and implementation technology. For different structure of feeders, the corresponding criterions and threshold setting rules are provided. In view of the current condition of distribution network, a self-synchronization scheme using fault signal is proposed and realized. And the communication protocols used for data exchange of differential protection based on peer to peer communication is discussed according to the new development of distribution automation communication architecture. Finally, the proposed protection prototype is developed based on a platform of intelligent distribution terminal, and the test results have verified the feasibility of the protection scheme.