基于阻抗匹配的输电线路在线取能方法研究  

Research on On-line Energy Acquisition Method for Transmission Lines Based on Impedance Matching

作　　者：刘铮[1] 樊绍胜[1] 胡劼睿 LIU Zheng;FAN Shaosheng;HU Jierui(School of Electrical and Information Engineering,Changsha University of Science and Technology,Changsha 410114,Hunan Province,China)

机构地区：[1]长沙理工大学电气与信息工程学院

出　　处：《中国电机工程学报》2019年第23期6867-6876,共10页Proceedings of the CSEE

基　　金：国家自然科学基金项目(61473049,51877011);电力机器人湖南省重点实验室项目(2018TP1025)~~

摘　　要：针对常规电流互感器在线取能方法无法在较宽的输电线路电流变化范围内,实现稳定较大功率输出的问题,提出了基于阻抗匹配的输电线路在线取能方法。该方法利用套在输电线路上磁芯的励磁电感与磁芯副边匹配电容实现并联谐振,大幅增加线路阻抗从而抑制线路上的电流。同时通过分流的方式将输电线路上的负荷电流导入负载实现功率输出。通过分析该方法取能原理,建立基于阻抗匹配的输电线路在线取能电路模型,推导出取能电路模型中各参数与取能功率间的关系,继而实现取能电路与负载阻抗相匹配,提高在线取能功率。最后的仿真以及实验表明:在输电线路电流为50A时,取能电路的输出能达到15.44W,折算得到功率密度达到了25733W/m^3。是相同条件下常规电流互感器取能方法输出功率密度2倍以上,已经能够支撑一些低功耗监测仪器的供电需求。当线路电流达到80A以上,取能电路的输出功率更是可以达到30W左右,已具有足够的供能能力。In view of the problem that the conventional current transformer on-line energy acquisition method cannot achieve stable and large power output under a wide range changes of transmission line current,an on-line energy acquisition method for transmission lines based on impedance matching was proposed.In this method,parallel resonance is generated by matching the secondary winding of the open gap magnetic core with its magnetizing impedance,thus the equivalent impedance of the damping branch of the magnetic core is increased.So that the load can get more electric energy by more current separated by the other branch.The energy acquisition method has the advantages of low cost,easy installation,wide range of power acquisition,large and stable power supply.The final simulation and experiments show that the novel method can achieve 15.44 W output when the bus current is 50 A,while the power density of the system reaches to 25733 W/m3,which is two times of the traditional method.And the energy obtained is able to support some low-power monitoring instruments.While the power output is reach about 30 W when the line current reaches more than 80 A,which has enough power supply capacity.

关 键 词：在线取能 磁芯 励磁阻抗 阻抗匹配 输出功率 

分 类 号：TM75[电气工程—电力系统及自动化]