Harmonic voltage via nonlinear frequency synthesized coupling on steel plane with common-ground

The ground current injected by the power-electronic converters causes distorted in isolated systems, which may generate new electromagnetic interference, especially at some new frequencies. Focusing on the distorted loop voltages at new interference frequencies, this paper presents the nonlinear characteristic and mechanics of frequency synthesized coupling via common-ground of steel plane. The nonuniform distribution of magnetic intensity in steel plane is calculated, also the nonlinearity of common-mode impedance is analyzed based on nonlinear magnetization. Then the mechanics on generating harmonic voltage at nonlinear synthesized frequencies is explained via theory and certified via experiment. Meanwhile the relation between harmonic voltage and parameters of injected ground currents (including magnitude and frequency) is investigated. Finally the rationale of nonlinear frequency synthesized coupling via common-ground of steel plane is interpreted.