环形直流配电网保护方法研究  

Research on Protection Method for Ring DC Distribution Network

作　　者：王成[1] 秦文萍[1] 韩肖清[1] 上官鑫 WANG Cheng;QIN Wenping;HAN Xiaoqing;SHANGGUAN Xin(Shanxi Key Laboratory of Power System Operation&Control,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]电力系统运行与控制山西省重点实验室(太原理工大学),太原030024

出　　处：《电力系统及其自动化学报》2020年第7期86-94,共9页Proceedings of the CSU-EPSA

摘　　要：本文以直流环形配电网为研究对象,深入分析了当直流线路发生接地故障时直流侧电压的故障特性,并据此提出了基于局部测量的直流配电网故障检测的保护方案。该方案以过电流保护和电流变化率保护为启动判据,并利用二次时变函数来预测故障时的线路侧电压,以故障时刻线路侧的预测电压和实测电压的差值作为主保护动作依据,配备欠压保护为后备保护以确保在故障情况下环形直流配电网能够安全稳定运行。本文增加了补充判据,进一步区分区内故障和区外故障,防止保护误动作。基于实时数字仿真器RTDS(real time digital simulator)对环形直流配电网保护方案进行仿真研究,验证了所提方案的可行性与有效性。In this paper,a DC ring distribution network is taken as the research object,and the fault characteristics of DC-side voltage when a DC line is grounded is analyzed in depth. On this basis,a protection scheme for the DC distribution network is proposed based on local measurement,in which the overcurrent protection and the varying rate of current are used as the starting criterion and the quadratic time-varying function is used to predict the line-side voltage at the time of fault. The difference between the predicted and measured voltages on the line side at the time of fault is used as the basis of main protection action,and the undervoltage protection is adopted as backup protection to ensure the safe and stable operation of the ring DC distribution network under fault. In addition,a supplementary criterion is added to further distinguish between faults inside and outside the protection zone,thus preventing the protection from malfunctions. A real-time digital simulator(RTDS)is used to simulate the proposed protection scheme for the ring DC distribution network,and results verify its feasibility and effectiveness.

关 键 词：环形配电网 接地故障 预测电压 实测电压 实时数字仿真器 

分 类 号：TM771[电气工程—电力系统及自动化]