Investigation of Cable Length Influence on EMI Spectrum in a WBG-Based Drive System

Despite the advantages of a wide band gap (WBG)based motor drive system, the electromagnetic interface (EMI) caused by WBG devices is a critical issue which should be taken care of. This paper investigates the influences of cable length on electromagnetic interface (EMI) in a WBG-based drive system. This study shows its importance to adopt the actual length of cable installed in the drive system in order to make the test results more representative of real system level operation condition. Analysis is obtained on the EMI noise generated in a WBG-based drive system influenced from different cable length. This study is investigated based on the comparison of frequency response of common mode (CM) and differential mode (DM) impedance and the EMI spectrum. The CM and DM impedances influences in CM noise and overvoltage across output terminal impacts DM noise spectrum. The experiments results are given for the 250V DC input converter with 60 Hz, 105V and 4A Line to Line AC rms output with R-L load in a three-phase drive system with no cable, using 1- and 6-meter cables between converter and the load.