Analytical model of EMI sources on the network level including power electronic converters

摘要

Since studies are intended to be used to predict the compliance with electromagnetic standards, an accurate computing of both common and differential mode conducted noise is necessary. Nowadays, modern networks-as car's network supplying many electrical actuators-include many power converters to manage efficiently power transfer, as well as a long cable (conductors), which creates new issues (e.g. interaction between cable and converter's noise sources). Hence, the ElectroMagnetic Compatibility “EMC” study becomes more complex. For this reason, in this paper we propose an analytical model to compute noise sources generating conducted signals within the network, at any site (all along the cable). Firstly, noise sources modelling the EMC behaviour of converters connected to the DC-network, are extracted and identified in both frequency and time domains. As a result, converter's electric equations modelling its behaviour are performed by defining a mathematical switching function. The model is assessed with time domain simulations and validated by experimental measurements. Secondly, the extracted converter's model, based on equivalent noise sources, is used to predict the conducted noise inside a defined network, at any location of the cable (network). The process of the network's modelling is done by using the Transmission Line theory (TL) of lossless bifilar lines. This network's model is crucial for EMC analysis, to evaluate the interaction degree between both noise sources and cable parameters. Finally, the network's model is tested by a time domain simulation (LTSpice), and validated by an experimental setup.