低压电网在130MHz频段的阻抗测量与特性分析-电网技术.PDF

29 卷 19 期 电 网 技 术 Vol. 29 No. 19 2005 年10 月 Power System Technology Oct. 2005 文章编号：1000-3673 （2005 ）19-0050-05 中图分类号：TN913.6 文献标识码：A 学科代码：5105010 低压电网在1~30MHz 频段的阻抗测量与特性分析 涛，杨晓宪，张保会 （西安交通大学电气工程学院，陕西省 西安市 710049 ） Measurement and Research of Impedance Characteristics of Low Voltage Power Networks within Frequency Band from 1MHz to 30MHz ZHENG Tao，YANG Xiao-xian，ZHANG Bao-hui （School of Electrical Engineering，Xi an Jiaotong University，Xi an 710049 ，Shaanxi Province，China ） ABSTRACT: On the basis of continuous measurement during 网本身是为传输工频电能而设计的，利用电力网 24 hours for three typical low voltage power networks, the 高频载波传输数据会存在许多问题，主要是载波 impedance characteristic of low voltage power network within 频带的限制，另外对低压电网信道的特性也缺乏足 the frequency band from 1MHz to 30MHz is researched. The 够的认识。目前国内外在此方面的研究主要是通过 method to measure the impedance of low voltage power 测量分析噪声、信号衰减及阻抗失配的情况来建 network by network analyzer is discussed and the features that [1-9] 信道模型 。 how the impedance of low voltage power network varies with 信号的衰减主要与传输线路的长度及多次的 frequency, time and location is analyzed. Analysis results show that within the frequency band from 1MHz to 30MHz the 多径反射有关，因为多径反射是由于电力调制解调 impedance of low voltage power network varies from more 器与低压电网的阻抗不匹配以及信号通过低压电 than ten ohms to one thousand ohms and in general it decreases 网中的阻抗不连续点造成的，所以研究低压电网的 with the increment of frequency. When frequency is higher 阻抗特性，改善传输系统的阻抗匹配程度，可以明 than 20