This work presents the circuit simulations and the conventional signal processing technique (Wiener filtering) in order to reconstruct conducted ElectroMagnetic Interferences (EMI), generated and propagated in power electronics converters. In the simulation study, the most accurate presently available models of components of circuit have been used and improved. The proposed Wiener filtering method allows to identifying the transfer function between source and generated perturbations. It can be useful for better understanding of the origin of the disturbances of such complex system and may be helpful in converters designing, concerning particularly control lows or switching modes. The proposed method has been developed and validated on simply DC boost structure and the applied to voltage inverters using PWM, PDM and finally using resonance (PQRDCLI topology). It proved that, EMI level and shape, depend on converter state.