Comparative Analysis of Various Magnetic Cores for Current Sensing in Active EMI Filters

Characterisation of magnetic materials is indispensable for Electromagnetic Interference (EMI) filtering in automotive electric drive (eDrive) systems. Usage of magnetic cores for passive EMI filtration is a well-recognised principle, however, the use of magnetic cores as current sensing elements has not been investigated thoroughly in literature. Precise analytical characterisation of power loss and saturation is important to predict the performance of magnetic core as a current sensing device. Particularly, in Active EMI Filter (AEF) applications, where the magnetic core material is exploited as a current sensing element. The effective sensing and filtration of EMI noise is influenced considerably by the material properties (complex permeability, saturation, and thermal behavior) of the current sensor employed as a current Transformer (CT). To investigate various attributes of magnetic current sensors and to ensure efficient detection of EMI noise in eDrive systems, this paper presents an analytical comparison of three distinctive magnetic cores.