Conference Agenda

Meeting EMC requirements on conducted emissions is one decisive development goal for modern e-drive systems. The well-known approach to achieve limits for 800 V systems via a filter comes with some drawbacks, like the increase of size or cost. Having those disadvantages in mind, the here proposed solution is to reduce the level of interference during operation by applying different modulation algorithms. Here the achieved improvements are quantified via a validated numerical computer model for an industrial automotive powertrain. As baseline for the comparison, a widely used modulation algorithm (Space Vector Modulation) is taken. Improvements between the investigated algorithms and the reference are shown for conducted emission results in frequency domain.

In motor drive systems, a long motor cable can parasitically couple to the ground plane, leading to violations of emission limits. This study investigates this phenomenon in detail through both measurements and simulations. To this end, an analytical model is introduced to predict internal common mode (CM) cable resonance and ground resonance frequencies, where conducted noise emissions are amplified. The paper further explores the role of cable shield imperfections and mode conversion in the excitation of antenna mode (AM) currents using 3D simulation. The paper concludes with the identification of efficient filtering schemes to damp the typical internal CM cable resonance and the ground resonance, offering solutions for mitigating conducted emission issues in motor drive systems.

This work describes a fully integrated computational framework to estimate conducted missions of 3-phase grid-connected inverters as a function of the used circuit topology and switching modulation schemes. The circuit’s functionality is emulated mathematically using Python to obtain the Common-Mode (CM) and Differential-Mode (DM) time domain output voltage waveform, which is post-processed using a software-emulated EMI receiver. The result is an accurate prediction of unfiltered frequency domain raw emissions, while providing the flexibility to compare different inverter topologies and pulse width modulation strategies with least amount of time and effort. Additionally, the framework allows to introduce disturbances on modulation as well as inverter level for a comprehensive analysis.

This study investigates electromagnetic emissions mechanisms below 30 MHz due to high voltage switching of power devices. The relationship between conducted and radiated emissions is discussed. A prototype buck converter with a 300 A / 1200 V IGBT module is used to analyze switching behavior at switching speeds from 1.5 kV/μs to 28 kV/μs, using time-domain measurement methods. It is found that switching behavior affects both conducted and radiated emissions, particularly from 10 MHz to 30 MHz. Furthermore, radiation mechanisms of the buck converter are experimentally analyzed by changing its configurations. The results show that the buck converter exhibits an incidental radiated emission mechanism involving the protective earth cable, which acts as a monopole antenna due to potential fluctuations relative to the ground. The mechanism, which bypasses the conventional common mode emission path, degrades the effectiveness of choke coils and filters.