摘要
智能配电网可接纳大量分布式电源(distributed generation,DG),受DG故障特性和控制策略影响,智能配电网故障判断方法的灵敏性和可靠性面临挑战。提出了一种基于工作电压相位比较的故障判断方法,首先,以被保护线路的数学模型为切入点,分析工作电压在被保护线路内、外部发生故障时的变化规律;然后,确定了整定阻抗的幅值和相角的取值原则,提出了基于工作电压相位比较的故障判断方法;最后,分析了T接支路对故障判断方法的影响,并推导了影响故障判断正确性的边界条件。采用PSCAD软件搭建了仿真模型,仿真结果表明,当线路阻抗性质改变及线路存在T接分支时,该故障判断方法能够可靠区分被保护线路内、外部故障,保护动作特性基本不受DG的影响,能够对配电网故障做出可靠的判断。
Smart distribution network can accept a large number of distributed generation(DG).Affected by DG fault characteristics and control strategies,the sensitivity and reliability of fault diagnosis methods for smart distribution network are challenged.A fault judgment method based on phase comparison of working voltage is proposed.Firstly,the mathematical model of the protected line is taken as the starting point to analyze the variation law of the working voltage when faults occur inside and outside of the protected line.Then the principle of setting amplitude and phase angle of the impedance is determined,and the fault judgment method based on the phase comparison of the working voltage is given.Finally,the influence of the T branch on the fault judgment method is analyzed,and the boundary conditions affecting the correctness of the fault judgment are derived.The simulation model is built by PSCAD,the simulation results show that when the line impedance nature changes and the line has T-connected branches,the fault judgment method proposed in this paper can reliably distinguish the internal and external faults of the protected line,and the protection characteristics are basically not affected by DG,which can make a reliable judgment on the fault.
作者
王瑞梅
丛伟
王泽乾
张子衿
古千硕
张永杰
WANG Ruimei;CONG Wei;WANG Zeqian;ZHANG Zijin;GU Qianshuo;ZHANG Yongjie(Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education(Shandong University),Jinan 250061,China;Qingda o Power Supply Company,State Grid Shandong Electric Power Company,Qingdao 266001,China)
出处
《供用电》
2023年第6期26-33,共8页
Distribution & Utilization
基金
国家自然科学基金项目(51877126)。
关键词
智能配电网
分布式电源
故障判断方法
工作电压
整定阻抗
smart distribution network
distributed generation
fault judgment method
operating voltage
setting impedance
