基于混合调制的海底直流电缆故障定位方法  

Fault Location Method for Submarine DC Cable Based on Mixed Modulation

作　　者：白龙雷 范道平 罗博 游江 马泽军 李靖德 邹亮[2] BAI Longlei;FAN Daoping;LUO Bo;YOU Jiang;MA Zejun;LI Jingde;ZOU Liang(Yantai Research Institute,Harbin Engineering University,Yantai 264006,Shandong Province,China;School of Electrical Engineering,Shandong University,Jinan 250061,Shandong Province,China)

机构地区：[1]哈尔滨工程大学烟台研究院,山东省烟台市264006 [2]山东大学电气工程学院,山东省济南市250061

出　　处：《中国电机工程学报》2025年第4期1623-1631,I0033,共10页PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING

基　　金：国家自然科学基金项目(52307006);烟台市重大创新科技项目(2023ZDCX015)。

摘　　要：近年来,海底直流电缆因受海水侵蚀、船锚损伤等破坏而引发的长时间断电事故频繁发生,严重威胁到水下输电系统的安全稳定运行,快速准确定位故障源对提升电缆绝缘可靠性具有重要意义。而现有的扩展频谱时域反射法因其测距范围受到码元持续时间限制,导致测试效率和准确度均偏低,为此,该文提出一种混合调制的方法,将码元持续时间不同的m序列进行相乘调制,通过正弦信号对其进行二进制相移键控调制,得到涵盖故障信息丰富的混频信号,既可实现宽范围测距,又能提高测试效率与精度。通过模型推导与实验验证,模拟海底电缆断线故障并进行定位研究。结果表明,m序列的周期与测距范围成正比,而码元持续时间则与测距盲区呈正相关关系。基于此,该文将码元持续时间为1和0.1μs的m序列进行调制实验,结果表明,测距范围分别从3141和314.1 m扩展至3235.23 m,测距盲区进一步减小。因此,利用所提出的混合调制方法,可有效克服现有方法的弊端,极大提高海底电缆故障定位效率和精度。In recent years,long-term power failure accidents of submarine DC cables have occurred frequently due to damage factors such as seawater erosion and anchor damage,posing a serious threat to the safe and stable operation of underwater transmission systems.It is of great significance to locate the fault source quickly and accurately for improving the reliability of cable insulation.However,the existing spread spectrum time-domain reflection method has low testing efficiency and accuracy due to its limited ranging range constrained by symbol duration.Therefore,this paper proposes a mixed modulation method,which multiplies m sequences with different symbol durations and modulates them through binary phase shift keying using a sine signal,resulting in a mixed frequency signal rich in fault information.This method can realize wide range ranging and improve the testing efficiency and accuracy.Through model derivation and experimental verification,a submarine cable break fault is simulated and studied for location.The results show that the period of the m sequence is proportional to the ranging range,while the duration of the symbol is positively correlated with the blind spot of the ranging.Based on this,modulation experiments are carried out on m sequences with symbol durations of 1μs and 0.1μs.The results show that the ranging range is extended from 3141 m and 314.1 m to 3235.23 m,respectively,and the ranging blind spot is further reduced.Therefore,using the mixed modulation method proposed in this paper can effectively overcome the drawbacks of existing methods and greatly improve the efficiency and accuracy of submarine cable fault location.

关 键 词：混合调制 电缆故障检测 扩展频谱时域反射法 海底直流电缆 

分 类 号：TM75[电气工程—电力系统及自动化]