放射直流微电网短路故障保护策略  

Protection strategy of short circuit fault in radial DC microgrid

作　　者：张伟亮 张辉[1,2] 支娜[1] 王韩伟[1] 杜明桥[1] ZHANG Weiliang;ZHANG Hui;ZHI Na;WANG Hanwei;DU Mingqiao(School of Electrical Engineering,Xi’an University of Technology,Xi’an 710048,China;State Key Laboratory of Control and Simulation of Power System and Generation Equipment,Tsinghua University,Beijing 100084,China)

机构地区：[1]西安理工大学电气工程学院,陕西西安710048 [2]清华大学电力系统及发电设备安全控制和仿真国家重点实验室,北京100084

出　　处：《电力自动化设备》2021年第5期203-209,共7页Electric Power Automation Equipment

基　　金：国家自然科学基金面上项目(51877175,52077176);陕西省重点研发计划资助项目(2017ZDXM-GY-003)。

摘　　要：考虑直流微电网故障电流突增、电压突降特性,提出基于支路两端导纳差值导数的保护方法。通过检测支路两端的电流和电压,计算支路两端导纳的差值并求导,以支路导纳差值的导数作为故障判据,该判据充分利用了故障线路电压和电流参量,提高了保护灵敏度,且导纳差值的导数在故障发生初始阶段最大,可快速与动作阈值比较,判断故障发生与否,减少了故障检测时等待电流或电压变化至阈值的时间。将所提保护方法与过电流保护和低电压保护进行对比,结果证实了所提方法在速动性、灵敏性和保护范围方面性能更好。Considering the characteristics of fault current surge and voltage drop of DC microgrid,a protec⁃tion method based on derivative of admittance deference between two ends of the branch is proposed.By detecting the current and voltage of two ends of the branch,the admittance difference between two ends of the branch is calculated and its derivative is obtained.Taking the derivative of admittance difference as the fault criterion,the voltage and current parameters of the fault line are fully used to improve the sensi⁃tivity of the protection.The derivative of admittance difference is the largest at the initial phase of the fault,which can be quickly compared with the setting threshold to judge whether the fault occurs or not,thus reducing the time of waiting for the current or voltage to change to the threshold during fault detec⁃tion.The proposed method is compared with the over current protection and under voltage protection.The results show that the proposed method has better performance in the aspects of speed,sensitivity and pro⁃tection range.

关 键 词：直流微电网 故障检测 导纳 灵敏度 速动性 

分 类 号：TM73[电气工程—电力系统及自动化] TM727