中国电力 ›› 2024, Vol. 57 ›› Issue (10): 78-89.DOI: 10.11930/j.issn.1004-9649.202401043

• 新型配电系统保护与控制关键技术 • 上一篇    下一篇

注入电流分布特性辨识的配电网故障选线方法

王晓卫1(), 岳阳1(), 郭亮2(), 王雪1, 王毅钊3, 张志华3, 杨峰峰4   

  1. 1. 西安理工大学 电气工程学院,陕西 西安 710054
    2. 国网江西省电力有限公司电力科学研究院,江西 南昌 330000
    3. 国网陕西省电力有限公司电力科学研究院,陕西 西安 710100
    4. 浙江省送变电工程有限公司,浙江 杭州 310020
  • 收稿日期:2024-01-09 出版日期:2024-10-28 发布日期:2024-10-25
  • 作者简介:王晓卫(1983—),男,通信作者,博士,副教授,从事电力系统继电保护、配电网接地故障处理研究,E-mail:proceedings@126.com
    岳阳(1995—),男,硕士研究生,从事电力系统继电保护研究,E-mail:yue4230@126.com
    郭亮(1986—),男,硕士,高级工程师,从事配电网继电保护研究,E-mail:guoliangxinyu@126.com
  • 基金资助:
    国家自然科学基金资助项目(52177114)。

Injection Current Distribution Characteristics Identification Based Distribution-Level Fault Line Selection

Xiaowei WANG1(), Yang YUE1(), Liang GUO2(), Xue WANG1, Yizhao WANG3, Zhihua ZHANG3, Fengfeng YANG4   

  1. 1. School of Electrical Engineering, Xi'an University of Technology, Xi'an 710054, China
    2. Institute of Electric Power Research of Jiangxi Electric Power Company, Nanchang 330000, China
    3. Institute of Electric Power Research of Shaanxi Electric Power Company, Xi'an 710100, China
    4. Zhejiang Electric Transmission & Transformation Co., Ltd., Hangzhou 310020, China
  • Received:2024-01-09 Online:2024-10-28 Published:2024-10-25
  • Supported by:
    This work is supported by National Natural Science Foundation of China (No.52177114).

摘要:

针对谐振接地系统单相接地故障特征微弱,基于故障特征的选线方法灵敏度和可靠性降低的问题,提出一种主动注入信号辨识的故障选线方法。首先,推导了注入电流受线路对地导纳影响下的分布特性,利用此分布特性构造选线判据。然后,从不同角度分析了注入信号对系统运行的影响,选择适宜参数的注入信号。考虑降低注入频率能够提高主动注入式选线方法的耐过渡电阻能力,故选择注入低频信号。测量注入信号后各条馈线的零序电流,选择稳态零序电流时间窗,利用Prony算法辨识各条线路零序电流中25 Hz电流幅值完成故障选线。最后,Pscad仿真和现场实测波形验证结果表明,该方法在不同故障场景下均能准确实现故障选线,且具有良好的耐过渡电阻能力。

关键词: 配电网, 单相接地故障, 注入法, Prony算法辨识, 故障选线

Abstract:

Addressing the challenges posed by the subtle characteristics of single-phase grounding faults in resonant grounding systems, which lead to decreased sensitivity and reliability in fault line selection methods reliant on these characteristics, an innovative approach for fault line selection through active injection signal identification is proposed. Initially, the distribution characteristics of the injected current, influenced by line-to-ground conductance, are derived. These characteristics then form the foundation for constructing a robust line selection criterion. Furthermore, a thorough analysis is conducted to assess the impact of the injected signal on system operation from various perspectives. This analysis leads to the selection of an optimal injection signal with suitable parameters. Notably, to enhance the method's resilience against transition resistance, a decision is made to inject a low-frequency signal. Subsequently, the zero-sequence current of each feeder line is measured after injecting the signal. A specific steady-state zero-sequence current time window is identified, and the Prony algorithm is employed to accurately discern the 25Hz current amplitude within the zero-sequence current of each line. This approach enables precise fault line selection. Extensive PSCAD simulations and on-site waveform measurements validate the effectiveness of this method. The results demonstrate its ability to accurately identify fault lines across a range of fault scenarios, while maintaining excellent resistance to transition resistance.

Key words: distribution network, single phase ground fault, injection method, Prony algorithm identification, fault line selection