Including Experimental Aging of Shielded Cables into Bulk Current Injection Simulations

Transfer impedance of shielded cables is a main characteristic to describe cable shielding performance at least up to 1 GHz. Traditionally, a cable shield consists of a braid, a foil, or a combination of them. Braids have attracted a significant amount of research interest, while foils have not. Published studies have concentrated on cable shielding performance when cables are new. In this paper, a highly accelerated aging method for shielded cables is presented and applied to a cable made up of a combination of a braid and foil shield. Finally, the effect of aging on system performance during bulk current injection (BCI) tests is assessed by circuit simulation.

I. Introduction

As automotive electrification and digitalization progress, shielded cables become increasingly important, on the one hand to convey information and to protect it from external disturbances, and on the other hand to confine the disturbance signals generated by electric drivetrains. When conveying information, a shielded cable often connects a sensor to an electronic control unit (ECU). This case will serve as an example in this paper. To provide proof of proper functioning of their product, automotive equipment suppliers use different electromagnetic compatibility (EMC) tests. One of them is bulk current injection (BCI) [1] that emulates the radio frequency (RF) field coupling to the equipment under test (EUT) through the cables connected to it. This paper aims to show, by simulation, how the BCI test result can be affected by aging of a shielded cable i.e. if more RF field is coupled to the EUT after the cable has aged.