摘要
随着配电网线路安全运行要求的提高,分布式电源注入的谐波会使得现有的选线方法失效,且单一判据的故障选线方法愈加难以胜任复杂配电网系统发生单相接地故障后的选线工作。因此文中提出了计及分布式电源注入谐波的谐振接地系统单相接地故障联合选线。针对谐振接地系统中出现单相接地故障后,故障线路与健全线路的暂态零序电流相位、周期变化不同的特点,先根据低频周期差异用多尺度交叉样本熵计算暂态零序电流,再根据高频相位差异用加权暂态能量法及同步挤压小波变换计算高频暂态零序电流的重构误差。此外,使用加权暂态能量法控制计算量并通过多尺度交叉样本熵、加权暂态能量和重构误差3个判据判定故障线路。实验结果显示,文中的联合选线法受不同故障条件的影响小,准确性高,抗干扰性强。
With the improvement of the requirements for the safe operation of distribution network lines,the harmonics injected by distributed power generation make the existing line selection methods ineffective,and the fault line selection method with a single criterion becomes more and more difficult to meet the line selection work after the single-phase ground fault occurs in the complex distribution network system.Therefore,a single-phase grounding fault joint line selection for resonant grounding system considering the injection harmonics of distributed power sources is proposed.In view of the characteristics of different phases and periodic changes of transient zero-sequence current of fault lines and sound lines after a single-phase grounding fault occurs in the resonant grounding system,the transient zero-sequence current is calculated by multi-scale cross-sample entropy according to the difference in low-frequency period.Then,according to the high-frequency phase difference,the weighted transient energy method and the synchronous squeeze wavelet transform are used to calculate the reconstruction error of the high-frequency transient zero-sequence current.In addition,the weighted transient energy method is used to control the calculation amount and determine the fault line through three criteria:multi-scale cross-sample entropy,weighted transient energy and reconstruction error.The experimental results show that the joint line selection method is less affected by different fault conditions and this method has high accuracy and strong anti-interference.
作者
李琰
赵莹
杜磊
徐天奇
田业
LI Yan;ZHAO Ying;DU Lei;XU Tianqi;TIAN Ye(The Key Laboratory of Cyber-physical Power System of Yunnan Colleges and Universities,University Key Laboratory of Information and Communication on Security Backup and Recovery in Yunnan Province,Yunnan Minzu University,Kunming 650504,China;Beijing Power Transmission Co.,Ltd.,Beijing 102401,China)
出处
《电力工程技术》
北大核心
2023年第4期113-121,共9页
Electric Power Engineering Technology
基金
国家自然科学基金资助项目(62062068)。
关键词
分布式电源
谐振接地系统
联合选线
多尺度交叉样本熵
加权暂态能量
同步挤压小波变换
distributed power supply
resonant grounding system
joint line selection
multi-scale cross-sample entropy
weighted transient energy
synchronously squeeze wavelet transform
