Visualization of Noise Propagation in Grounding System

Abstract

This paper develops a probe for measuring the high frequency grounding potential and demonstrates its effectiveness. The developed probe is applied to a motor drive system and measures a potential difference between a grounding terminal and the motor frame connected by a grounding conductor. Moreover, this paper attempts to visualize noise propagation in a grounding system. An experimental system is constructed on a lattice-shaped ground plane. A three-phase cable stretched on the ground plane connects between a common-mode voltage source and a motor, and the motor frame is earthed to the ground plane. In experiment, the developed probes detect 25-point potentials, and reconstructing these 25 waveforms makes it possible to visualize noise propagation. In addition, influence of a common-mode choke upon the noise propagation are shown experimentally.