近地空间与电网相关的谐波辐射现象研究  

Research on Harmonic Radiation Related to the Power Grid inthe Near-Earth Space

作　　者：张敬雯 吴静[1] 谢天宇 Zhang Jingwen;Wu Jing;Xie Tianyu(School of Automation Science and Electrical Engineering Beihang University,Beijing 100191 China)

机构地区：[1]北京航空航天大学自动化科学与电气工程学院,北京100191

出　　处：《电工技术学报》2023年第11期2861-2869,共9页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(5177706);北京市自然科学基金(8222063)资助项目。

摘　　要：大量卫星探测结果表明近地空间存在与地面电网谐波频率一致的辐射现象,但相应的谐波辐射源仍不确定。通过分析与晋东南—南阳—荆门特高压交流输电工程走向接近的DEMETER卫星轨道上的电场强度探测数据,发现空间存在2~5 kHz频带内的谐波辐射事件,且事件的数量在该特高压输电工程投入运行后急剧增加。地面实测结果表明,特高压输电工程首端确实存在数千赫兹的谐波辐射。利用偶极子等效地面谐波辐射源,基于全波模型,分析了其产生的电磁波在半球空间电离层中的传播特点,并与卫星探测结果进行了对比,表明近地空间谐波辐射现象与地面变电站的谐波辐射具有一定关联。此外研究了甚低频(VLF)电网谐波辐射在南北地磁共轭空间传播的机理,并利用卫星探测实例进行了初步验证。A large amount of satellite-based observations show that the radiation corresponding to the power grid harmonic frequencies with the strength of more than 10dB greater than background noise exits in the near-Earth space.Some references believe that it is originated from power lines and name it power line harmonic radiation(PLHR).This paper studies the specific source of the power grid corresponding to PLHR by comparing the ground-based measurements with the satellite-based measurements and discusses its propagation mechanism in the ionosphere The spectrogram of the electric field strength observed along satellite DEMETER orbits that point in the same general direction as the Jindongnan–Nanyang–Jingmen ultra–high voltage(UHV)AC transmission line has been analyzed first.The results show after the UHV project went into operation at the end of 2008,the number of PLHR events in the frequency range of 2~5 kHz occurring in the ionosphere increased sharply.The ground-based measurement results show that the harmonic radiations at 2.5~3 kHz and 4~4.5 kHz do exist at the head end of the UHV project.The above results indicate the source of PLHR is closely connected with the UHV project.The full-wave model is used to explore the propagation characteristics of the UHV project's electromagnetic wave in the ionosphere.A horizontal dipole with the length of 200 m and the height of 12 m above the ground is used to equivalent the harmonic radiation source and the ionosphere is regarded as a stratified,linear,anisotropic and uniform plasma.The numerical results show that the electric field strength reaches the maximum values 0.15μV/m of 2.8 kHz at(660 km,530 km)in which 660 km is the altitude of DEMETER and 530 km is the distance away from DEMETER in the horizontal direction and 0.07μV/m of 4.25 kHz at(660 km,540 km),respectively.These values are close to but generally lower than the electric field strength of 0.09~0.27μV/m observed by DEMETER which is 551 km away from the UHV line in the horizontal direction.The difference

关 键 词：特高压电网 谐波辐射 近地空间 卫星探测 

分 类 号：TN011.2[电子电信—物理电子学] TM154.1[电气工程—电工理论与新技术]