信号传输电缆低频下电磁兼容性设计

Electromagnetic Compatibility Design of Signal Transmission Cable under Low-Frequency

不同于高频电磁干扰环境,在低频电磁干扰环境中电场影响较小而磁场影响较大。为了保证信号传输用电缆能够在恶劣的低频电磁环境中有效可靠地传输各种弱电信号,从低频下的电磁场屏蔽原理、屏蔽效能理论计算、屏蔽材料选用、屏蔽结构选择等方面详细阐述了提高电缆的抗低频电磁干扰能力的设计方法,特别是低频环境下磁屏蔽效能提高途径。经实际验证,通过多层复合屏蔽形式设计,利用不同屏蔽层之间的电磁反射及吸收,电缆可具有抗高低频电磁干扰的能力。

Unlike high-frequency electromagnetic interference environments, in low-frequency electromagnetic interference environments, the influence of electric field is relatively small, while the influence of magnetic field is relatively large. In order to ensure that signal transmission cables can effectively and reliably transmit various weak current signals in harsh low-frequency electromagnetic environments, the design methods for improving the cable's resistance to low-frequency electromagnetic interference are elaborated, especially the ways to improve magnetic shielding effectiveness in low-frequency environments, from the principles of electromagnetic shielding at low-frequency, theoretical calculation of shielding effectiveness, selection of shielding materials, and selection of shielding structures. Through practical verification, the cable can have the ability to resist high and low frequency electromagnetic interference by designing a multi-layer composite shielding form and utilizing electromagnetic reflection and absorption between different shielding layers.