SPICE Simulation of Modal Impedances in Automotive Powertrains under Different Operating Conditions

Abstract

The spread of information-communication technology (ICT) devices in full and/or hybrid electric vehicles is posing increasing issues about coexistence between communication and electric power systems. Particularly, under different operating conditions, the time-variant and nonlinear behavior of the involved power-electronic devices may cause detrimental electromagnetic interference (EMI) effects for onboard ICT devices. The use of passive or active EMI filters can mitigate EMI, yet their effective design requires the knowledge of the actual modal impedances of the involved components. With the final objective to support EMI filter design, in this work, the frequency response of the common mode (CM) and differential mode (DM) impedances of a complete automotive power train is investigated under different operating conditions. Moreover, both low-frequency functional aspects and high-frequency parasitic effects are considered and modelled properly.

Black-box Modeling of Converters in Renewable Energy Systems for EMC Assessment: Overview and Discussion of Available Models

“…In this regard, it is worth mentioning that several models available in the literature were validated under operating conditions very close to those used for model extraction, thus making it difficult to clearly define their actual limitations. For example, from studies by Mazzola et al [25][26] it was inferred that the common-mode (CM) impedance of the converter could be effectively evaluated with the converter switched off. However, it was not possible to draw the same conclusion for the differential mode (DM) impedance because it exhibited a different frequency response when the drive was ON or OFF.…”

Assessment of Validity Conditions for Black-Box EMI Modelling of DC/DC Converters

“…These setups mimic the injection method proposed in [11], where a transformer and an impedance analyzer are adopted in order to measure the model impedances with the converter switched on and under different operating conditions. SPICE modelling of the exploited setups was presented in [12], and applied in this work. CM and DM setups are shown in Fig.…”

“…However, this conclusion cannot be generalized to all converters without further investigations. Indeed, some recent works [11], [12] show that differently from the common mode (CM) impedance, which is mainly determined by the effects due to parasitics, the differential mode (DM) impedance may exhibit not-negligible sensitivity to the operating conditions. Therefore, extracting the black-box model of the converter under certain operating conditions does not assure model effectiveness for predicting the conducted emissions in other operating conditions.…”

“…The analysis is also extended to investigate the characteristics of the frequency response of the differential mode (DM) impedance. As a matter of fact, since previous investigations [11], [12] have proved its possible sensitivity to the operating conditions, measurement of the DM impedance under different operating conditions can provide useful hints to assess the feasibility of black-box modelling of commercial converters, for which detailed information on the internal architecture is not always available.…”

Enhanced Impedance Measurement to Predict Electromagnetic Interference Attenuation Provided by EMI Filters in Systems with AC/DC Converters

“…For instance, in [16], the EMI filter design took into account the terminal impedances of an inverterdriven motor system that were measured offline by an LCR meter. However, recent research has shown that the impedance of power electronics converters measured offline may not coincide with the actual impedance when the system is powered on [17,18]. Hence, the online impedance measurement is more appropriate for optimal filter design.…”