Modeling of a Current Injection System for Susceptibility Study

This article deals with the model of a high current injection system associated with its electrical generation-transformation-distribution chain able to reproduce differential or common-mode parasitic currents and voltages induced by the coupling between a nuclear electromagnetic pulse radiation on a global electrical network. Due to the quite complexity of the current injection system, the chosen modeling approach was to use the well-known equivalent Thevenin generator. Because of several hundreds of amperes and volts of current and/or voltage generated and their relatively large spectral occupancy of some tens of megahertz, the measurement of currents and voltages needed to build the model, were carried out with adequate sensors and equipment. Once the model built, the generators have been integrated into Spice circuit simulation tool in order to predict the differential and the common- mode currents and voltages induced at the input of switch-mode power supplies and, for later studies, at some different nodes.