Low-Frequency Conducted Emissions Assessment for Electric Powertrain

The conducted emissions (CE) in powertrain applications are a major concern due to the high current peaks and transients from torque profiles and sudden speed changes. This paper investigates the time-domain noises analytically through a curve-fitting process, whose results can be used to reproduce the noise waveforms avoiding the need to store the entire waveform. Besides, common-mode (CM) and differential-mode (DM) voltages from speed changes of a PMSM (permanent magnet synchronous motor) powertrain are compared, in terms of harmonic components and noise amplitude, by using line impedance stabilization network (LISN) according to different standards. It was observed that DM emissions, at low frequencies, are better coupled to DO-160G LISN and increase progressively with speed rise, while CM noise levels are kept constant.