Derivation and Application of Equivalent Circuits to Model Common-Mode Current in Microgrids

In this paper, a formalized common-mode (CM) modeling approach is proposed to transform mixed-mode power system models into their CM equivalent circuits. The approach is first validated through comparison of time-domain waveforms predicted by detailed mixed-mode and CM equivalent models of a representative ship power system. Subsequently, the approach is validated using hardware measurements of the Purdue reduced-scale naval dc microgrid. The experimental studies highlight the utility of the proposed modeling approach to assess design questions regarding placement and impedance of system grounds.