| Abstract |
This work considers the coupling effects between differential and common modes, which have an impact on the conducted electromagnetic noise generated by variable speed drive supplied from DC grid of an aircraft. Common mode noise, which origins from the differential mode, was observed during conducted EMI measurements at the output shielded cable, due to asymmetry of the cable. It is shown, that such noise can exceed the corresponding limit. The mixed mode scattering parameters are considered for the study of the mode coupling. They were measured and adopted for the output shielded cable. Finally, they were integrated into the frequency domain behavioural models in order to predict the EMI including mixed mode noise. The results are showing good accordance with the real setup measurements. It was also shown, that ignoring of the mixed mode noise can lead to the wrong design of EMI filters. The considered simulation approach can be applied to the other components of the system as well. The resulting models are proposed to be used for optimal design of EMI filters for a variable speed drive of more electric aircraft. |
