中国电力 ›› 2023, Vol. 56 ›› Issue (4): 184-191.DOI: 10.11930/j.issn.1004-9649.202211032

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基于DFFT的低压直流线路主动式接地故障定位方法

曹赋禄, 赵晋斌, 潘超, 毛玲, 屈克庆   

  1. 上海电力大学 电气工程学院, 上海 200090
  • 收稿日期:2022-11-10 修回日期:2023-02-11 发布日期:2023-04-26
  • 作者简介:曹赋禄(1998-),男,硕士研究生,从事电力电子化继电保护研究,E-mail:cfl1101008577@163.com;赵晋斌(1972-),男,通信作者,博士,教授,从事电力电子电路、装置与系统、电力电子电路的智能化及模块化技术、现代电力电子技术在电力系统中的应用、新能源发电技术、无线电能传输技术研究。E-mail:zhaojinbin@shiep.edu.cn
  • 基金资助:
    国家自然科学基金资助项目(52177184)。

An Active Ground Fault Location Method for Low-Voltage DC Lines Based on DFFT

CAO Fulu, ZHAO Jinbin, PAN Chao, MAO Ling, QU Keqing   

  1. School of Electrical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
  • Received:2022-11-10 Revised:2023-02-11 Published:2023-04-26
  • Supported by:
    This work is supported by National Natural Science Foundation of China (No.52177184).

摘要: 针对含电力电子变压器的低压直流电缆线路接地故障定位的问题,提出一种利用电力电子变压器主动注入的单端量故障定位方法,以快速排查故障并恢复供电。通过电力电子变压器中压端口向低压侧注入210 Hz频率的正弦电压信号,特征信号将通过高频变压器传输到低压侧电容,利用快速傅立叶变换提取并辨识电容电压与电流的特征参数,计算出故障后的线路阻抗。同时,采用二次曲线拟合构造曲线的方法降低频谱泄露及频域电抗波形振荡带来的阻抗误差,获取准确的故障位置。最后通过电磁暂态仿真软件PSCAD/EMTDC仿真结果,验证了所提方法对含电力电子变压器的低压直流线路接地故障的有效性,并具有抗噪声干扰能力和一定的耐过渡电阻能力。

关键词: 电力电子变压器, 主动注入式, 低压直流配电线路, 故障定位, 单端式

Abstract: For the problem of locating ground faults in low-voltage DC cable lines containing power electronic transformers, a single-ended volume fault location method using power electronic transformers with active injection is proposed for rapid fault detection and restoration of power supply. A sinusoidal voltage signal with 210 Hz frequency is injected into the low voltage side through the medium voltage port of the power electronic transformer. The characteristic signal will be transmitted to the low voltage side capacitor through the high frequency transformer, and the characteristic parameters of the capacitor voltage and current are extracted and identified using the fast Fourier transform to calculate the line impedance after the fault. At the same time, a secondary curve fitting construction curve method is used to reduce the impedance errors caused by spectral leakage and frequency domain reactance waveform oscillation and to obtain the accurate fault location. Finally, the PSCAD/EMTDC simulation results have verified the effectiveness of the proposed method for locating the ground faults of low-voltage DC lines containing power electronic transformers with noise interference resistance and certain transition resistance resistance.

Key words: power electronic transformers, active injection, low voltage DC distribution lines, fault location, single ended