This paper deals with system level EMC models for power electronics converter, able to investigate the conducted emissions in embedded grid, for instance. The model topology presented in this work is not symmetric and its identification does not rely on the usual Differential / Common Mode separation. The identification method is presented, and the model is validated in different asymmetric environments: a specific configuration with a modified LISN, and another one with minus connected to ground. Both approaches are carried out in simulation and experiment, for the simple example of a boost converter.