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EMI Characterization with Parasitic Modeling for a Permanent Magnet Motor Drive



Xudong Huang, Pepa Elton, Jih-Sheng Lai, Allen R. Hefner Jr., David W. Berning, Shaotang Chen, Thomas Nehl


In this paper , a permanent magnet ac motor drive is tested extensively, and the prominent frequencies are identified for their relationship with the noise sources and their propagation paths. Switching characteristics of the power MOSFETs are evaluated for the noise source modeling. Major parasitic components and noise propagating mode path are measured with the time-domain reflectometry method and verified with a 3-dimensional finite element analysis tool. The inverter circuit model is then constructed with major parasitic inductance and capacitance in device modules, passive components, leads, and interconnects. To verify the validity of the inverter model, a comparative study is performed with computer simulations and hardware experiments. The fundamental mechanisms by which the EMI noises are excited and propagated are analyzed, and the significant roles of parasitic elements coupling with device switching dynamics in EMI generation are examined. The results indicate that the identification of parasitic inductance helps verify the noise peaking frequencies. The noise mitigation effects of added dc choke and RC snubbers are also characterized and proven with both simulation and measurement.
Proceedings Title
Proc., IEEE Industry Applications Society (IAS) Annual Meeting
Conference Dates
October 12-16, 2003
Conference Location
Salt Lake City, UT, USA


common mode noise., filter, motor drive, switching noise, Time domain reflectrometry, EMI


Huang, X. , Elton, P. , Lai, J. , Hefner Jr., A. , Berning, D. , Chen, S. and Nehl, T. (2003), EMI Characterization with Parasitic Modeling for a Permanent Magnet Motor Drive, Proc., IEEE Industry Applications Society (IAS) Annual Meeting, Salt Lake City, UT, USA, [online], (Accessed April 18, 2024)
Created October 11, 2003, Updated October 12, 2021