Efficient EMI-Filters for High-Current Mobile Applications

Power converters generate electromagnetic interferences (EMI) in form of both conducted and radiated disturbances. These electromagnetic emissions are best reduced at their source and by additional shielding and filtering. Passive filtering of conducted emissions is well understood. However, the design of volume- and weight optimized solutions with significant current ratings and appropriate filter-attenuation needs to be addressed and is not available as off-the-shelf solution. This paper presents compact high-current filter solutions for mobile applications and describes their impact concerning the reduction of EMI. In particular, passive and active filters against common-mode interferences are discussed for 28VDC interfaces and 10-30 kW power applications.