R-L-C model of an Inverter DC bus for diagnosis purpose

In this paper, the authors present the modelling of the impedance variation of an inverter DC bus. Modelling is done by application of the PEEC method (Partial Element Equivalent Circuit) with an additional method for computing the local charge density (analytical formulas) in order to give the local capacity. This method has been implemented so as to extract the behaviour of the local charge density, specifically for busbar structure. Results obtained in the case of an approached busbar equivalent geometry are shown. A quantification of the edges importance for the charge repartition is presented, and so its link with the HF local capacitor influence. Moreover simulations of the values of the global DC bus impedance versus frequency are compared to measures. ©2007 IEEE.