摘要
为研究有损大地上的屏蔽电缆与外界电磁场耦合的感应电流分布特性,基于天线理论和传输线模型导出外场辐射下电缆屏蔽层耦合的异模感应电流和共模感应电流计算公式,推导了电缆端接不同负载时,电缆屏蔽层耦合的共模感应电流解析表达式,并研究了感应电流的分布特性,得到了电缆两端架空时谐振频率与电缆长度的关系。结果表明:异模感应电流、共模感应电流和总感应电流均随电缆架空高度的增大而增大;异模感应电流、共模感应电流和总感应电流均随大地电导率的增大而减小。研究成果可为计算感应电流的辐射大小提供理论依据和数据基础,同时对电缆的电磁防护有一定参考价值。
In order to research the induced current distribution characteristics for the external electromagnetic field coupling to shielded cable above a lossy ground, based on the antenna theory and transmission line model, the calculation formulas of differential mode（DM） induced current and common mode（CM） induced current are derived for the electromagnetic field coupling to cable sheath, the analytic expression of CM induced sheath current is obtained for different terminal loads of cable, the induced current distribution characteristics of the cable sheath is researched, and the relation- ship between resonance frequency and cable＇s length is acquired for the cable overhead at both ends. The results show that DM induced current, CM induced current, and total induced current all increase with the increase of cable height, but they all decrease with the increase of ground conductivity. The proposed results can provide a theoretical basis and data base for computing radiated emission of induced current and can be used as references to electromagnetic protection of cable.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2016年第8期2451-2456,共6页
High Voltage Engineering
基金
国家自然科学基金(U1434203)~~
关键词
场线耦合
感应电流分布特性
天线理论
传输线模型
异模感应电流
共模感应电流
electromagnetic field-to-line coupling
induced current distribution characteristics
antenna theory
transmission line model
differential mode induced current
common mode induced current
