Research on the influence of metal groove on wires coupling in EMU

More metal grooves were used in EMU to neatly arrange the wires. On one hand, they protect wires against external electromagnetic interference and reduce external radiation from the wires. On the other hand, the metal grooves create waveguide structures that affect the coupling among wires inside the metal grooves. To study the influence of the metal groove's different parameters on the coupling between wires, an equivalent metal groove model was established in this paper. In the equivalent model, it is very convenient to change the parameters of the metal groove. By changing these parameters, the results of wires coupling in a variety of cases that is not easy to realize in reality can be obtained. The results can provide an effective reference for the design of metal grooves. The equivalent model was validated by measurements.

I. Introduction

Nowadays, coupling of wires is a critical issue in electromagnetic compatibility (EMC) problems. Because of the limited space in EMU, the power wires may be arranged in parallel to signal wires of control systems for a long distance. Interference harmonics on the power wires may couple to the nearby signal wires via wires coupling, thus, lead to failures in the control system. In order to resolve the problem, signal wires usually go through the metal grooves to connect with the control system devices for reducing wires coupling and protect signal wires against external electromagnetic interference. However, the metal grooves creates a waveguide structure that will affect coupling between wires [1]. Therefore, the influence of metal groove on wires coupling must be studied.