Insertion loss of traction inverter electromagnetic interference filter as a function of noise source impedance

The noise source impedance has a major impact on the insertion loss (IL) of the traction inverter electromagnetic interference filter in electric cars. It is possible to determine the source impedance conditions at which the IL will be minimum or maximum. This paper exploits this to present a method for identifying critical frequency ranges regarding the minimum IL when the information about the source impedance is limited. Thus, the expectable IL can be predicted before the exact source impedance is known, and responses to changes in the termination impedance can be made more efficient.