130 | 0 | 2 |
Downloads | Citas | Reads |
为提升实验教学质量,该文设计了一种配电网单相接地故障选段实验。首先研制了接地故障实验平台,包括10 kV真型实验系统和接地电流识别装置。接着,提出了配电网接地故障选段的设计方案,并针对故障电流识别准确率低的工程普遍性问题,在深入分析健全区段与故障区段暂态零序功率累加和极性差异性的基础上,设计了一种基于遗传算法与小波包能量熵的特征频带优选的接地故障电流识别方法。实验结果表明,所提方法具有自适应、免阈值的优点,相对于其他文献方法具有较高的识别准确率。最后,针对不同的课程需求,设计了层次性实验,在提升学生的实践操作技能和增强实验教学效果方面发挥了积极作用。
Abstract:[Objective] A single-phase grounding fault is the most frequent type of fault in distribution networks, and identifying the fault accurately and locating the fault section for the safe operation of power networks is crucial. However, because of small fault current, weak fault characteristics, and poor dispersion, the accuracy of fault location in engineering practice is low. In order to enhance the quality of experimental teaching, students' cognition of single-phase grounding fault in distribution networks, and their practical analytical skills, this paper presents an experimental design scheme for the resonant grounding fault segment in distribution networks. [Methods] First, the design method of the single-phase grounding fault experiment platform is described, including the components of the 10 kV true type experiment system and the hardware and software designs of the single-phase fault grounding current identification terminal to build a real experimental environment for the research. Second, the design scheme of the distribution network grounding fault section is proposed. After an in-depth analysis of the polarity differences between the transient zero-sequence signals in the healthy section and the faulty section, it is found that when transient zero-sequence power is directly calculated, misjudgment will occur because of the influence of arc suppression coil compensation and noise interference. However, some frequency band information of the zero-sequence power contains characteristic information that can effectively suppress the interference. Based on this, the transient zero-sequence power is decomposed by a wavelet packet algorithm, in which the frequency band with strong energy entropy can stably reflect the state characteristics of the line. Considering the randomness and uncertainty of the fault arc and the presence of field noise, the high-entropy characteristic frequency bands of each fault sample are not the same, and the number of characteristic frequency bands available for selection is large. Therefore, this paper further proposes a feature frequency band optimization method based on a genetic algorithm and wavelet packet energy entropy. In the offline stage, the genetic algorithm is used to screen the massive historical data and optimize the selection of feature frequency bands to improve the identification accuracy of the fault section. In the single calculation stage, the five frequency bands with the highest wavelet packet energy entropy are selected as the characteristic frequency bands, and then, the fault characteristic frequency bands with strong characterization ability are determined by intersection operation. This method can effectively suppress the noise interference and enhance the identification performance of the fault section. [Results] Experimental results show that the proposed method is highly adaptive, requires no threshold in ground fault current identification, and achieves an accuracy of 95.24%. Compared with other methods in the literature, the proposed method can maintain higher recognition performance under various working conditions. Finally, hierarchical experiment schemes are designed according to different curriculum requirements for students to gradually master the whole process from fault mechanism analysis to advanced intelligent identification methods. [Conclusions] The experimental platform and single-phase grounding fault identification method not only improve the students' hands-on and engineering application capabilities but also lay the foundation for further research and application of single-phase grounding fault detection technology in distribution networks and provide an innovative practical teaching model for the cultivation of talent in the field of power engineering.
[1]邱伟强,郭谋发,郑泽胤.基于单一直流源级联H桥变流器的配电网接地故障柔性消弧方法[J].电网技术, 2019, 43(10):3848–3858.QIU W Q, GUO M F, ZHENG Z Y. Flexible arc suppression method for grounding faults in distribution networks based on cascaded H-bridge converter with a single DC source[J]. Power System Technology, 2019, 43(10):3848–3858.(in Chinese)
[2]高伟,唐钧益,林宝全,等.配电网单相接地故障虚拟仿真教学系统设计[J].实验技术与管理, 2022, 39(5):160–165.GAO W, TANG J Y, LIN B Q, et al. Design of virtual simulation teaching system for single-phase grounding faults in distribution networks[J]. Experimental Technology and Management, 2022,39(5):160–165.(in Chinese)
[3]邹长青,刘对,林兵,等.基于特征能量和BFAGA算法的含分布式电源配电网单相接地故障区段定位[J].高电压技术,2024, 50(6):2706–2715.ZOU C Q, LIU D, LIN B, et al. Section location of single-phase grounding faults in distribution networks with distributed generation based on characteristic energy and BFAGA algorithm[J].High Voltage Engineering, 2024, 50(6):2706–2715.(in Chinese)
[4]许可,范馨月,张恒荣.基于图卷积网络的配电网故障定位及故障类型识别[J].实验技术与管理, 2023, 40(1):26–30.XU K, FAN X Y, ZHANG H R. Fault location and fault type identification in distribution networks based on graph convolutional network[J]. Experimental Technology and Management, 2023,40(1):26–30.(in Chinese)
[5]王雪文,石访,张恒旭,等.基于暂态能量的小电流接地系统单相接地故障区段定位方法[J].电网技术, 2019, 43(3):818–825.WANG X W, SHI F, ZHANG H X, et al. Section location method for single-phase grounding faults in small-current grounding systems based on transient energy[J]. Power System Technology, 2019, 43(3):818–825.(in Chinese)
[6]郭谋发,刘世丹,杨耿杰.利用时频谱相似度识别的配电线路接地选线方法[J].中国电机工程学报, 2013, 33(19):183–190.GUO M F, LIU S D, YANG G J, et al. Grounding line selection method for distribution lines based on time-frequency spectrum similarity recognition[J]. Proceedings of the CSEE, 2013,33(19):183–190.(in Chinese)
[7]郭谋发,陈志欣,高伟,等.配电网继电保护培训系统设计与实现[J].实验技术与管理, 2019, 36(5):72–79.GUO M F, CHEN Z X, GAO W, et al. Design and implementation of relay protection training system for distribution networks[J]. Experimental Technology and Management, 2019,36(5):72–79.(in Chinese)
[8]侯义明.《配电网技术导则》修订背景和编制原则[J].供用电, 2017, 34(1):28–31.HOU Y M. Revision background and compilation principles of technical guidelines for distribution networks[J]. Power Supply and Utilization, 2017, 34(1):28–31.(in Chinese)
[9]郭谋发,高伟,陈彬,等.配电网自动化技术[M].第2版.北京:机械工业出版社, 2018.GUO M F, GAO W, CHEN B, et al. Distribution network automation technology[M]. 2nd ed. Beijing:China Machine Press, 2018.(in Chinese)
[10]刘源延,孔小兵,马乐乐,等.基于小波包变换与深度学习的超短期光伏功率预测[J].太阳能学报, 2024, 45(5):537–546.LIU Y Y, KONG X B, MA L L, et al. Ultra-short-term photovoltaic power prediction based on wavelet packet transform and deep learning[J]. Acta Energiae Solaris Sinica, 2024, 45(5):537–546.(in Chinese)
[11]白鹏,刘楠,董卓龙,等.基于遗传算法的元胞自动机复杂楼宇人员疏散模型[J].实验技术与管理, 2024, 41(8):236–243.BAI P, LIU N, DONG Z L, et al. Complex building personnel evacuation model based on genetic algorithm and cellular automaton[J]. Experimental Technology and Management,2024, 41(8):236–243.(in Chinese)
[12]聂兴毅,黄华,李旭东,等.基于改进小波包能量熵和阈值自适应的切削颤振在线监测[J].仪器仪表学报, 2024, 45(5):227–238.NIE X Y, HUANG H, LI X D, et al. Online monitoring of cutting chatter based on improved wavelet packet energy entropy and threshold self-adaptive[J]. Chinese Journal of Scientific Instrument, 2024, 45(5):227–238.(in Chinese)
[13]张浩,张大海,刘乃毓,等.基于改进VMD及ConvNeXt的小电流接地系统单相接地故障选线方法[J].高电压技术,2025, 51(2):730–741.ZHANG H, ZHANG D H, LIU N Y, et al. Single-phase grounding fault line selection method for small-current grounding systems based on improved VMD and ConvNeXt[J].High Voltage Engineering, 2025, 51(2):730–741.(in Chinese)
[14]张乃刚,张加胜,郑长明,等.基于零序电流幅值分布相似性的小电流接地故障定位方法[J].电力系统保护与控制, 2018,46(13):120–125.ZHANG N G, ZHANG J S, ZHENG C M, et al. Fault location method for small-current grounding systems based on similarity of zero-sequence current amplitude distribution[J]. Power System Protection and Control, 2018, 46(13):120–125.(in Chinese)
[15]林骏捷,林佳壕,郭谋发.基于多暂态特征量聚类的配电网接地故障区段定位方法[J].电气技术, 2023, 24(5):16–22.LIN J J, LIN J H, GUO M F, et al. Section location method for grounding faults in distribution networks based on multi-transient feature clustering[J]. Electrical Technology, 2023, 24(5):16–22.(in Chinese)
[16]李建设.基于多元智能理论的物理实验教学评价内容设计[J].实验技术与管理, 2013, 30(7):143–146.LI J S. Design of evaluation content for physics experiment teaching based on the theory of multiple intelligences[J].Experimental Technology and Management, 2013, 30(7):143–146.(in Chinese)
Basic Information:
DOI:10.16791/j.cnki.sjg.2025.07.005
China Classification Code:TM862
Citation Information:
[1]高伟,郑子杰,李育凤等.基于暂态零序功率特性的配电网单相接地故障选段实验设计[J].实验技术与管理,2025,42(07):34-42.DOI:10.16791/j.cnki.sjg.2025.07.005.
Fund Information:
福建省教育厅2022年本科高校教育教学研究项目(重大项目)(FBJG20220284); 福建省自然科学基金项目(2021J01633)