In-Circuit Differential-Mode Impedance Extraction at the AC Input of a Motor Drive System

TL;DR

This paper presents a non-contact, single-probe method using frequency-domain measurement to extract the differential-mode impedance at the AC input of a motor drive system, aiding in EMI noise evaluation.

Contribution

It introduces a novel single-probe setup for in-circuit impedance extraction, enabling non-contact and simple measurement of differential-mode impedance in motor drive systems.

Findings

Effective impedance extraction across different operating modes

Non-contact measurement reduces measurement complexity

Potential for improved EMI noise assessment

Abstract

The in-circuit differential-mode (DM) impedance at the AC input of a motor drive system (MDS) serves as a key parameter to evaluate and estimate the DM electromagnetic interference (EMI) noise caused by the switching of power semiconductor devices in the MDS. This paper discusses a single-probe setup (SPS) with frequency-domain measurement to extract the in-circuit DM impedance of an MDS under its different operating modes. The advantages of the SPS are its non-contact measurement and simple structure.