EMI characterisation of high power IGBT modules for traction application

Performances' improvement of the switching power drives in terms of switching losses reduction is accompanied by a significant increase in EMI problems. In this paper, an original experimental "single-shot" method is proposed, for the evaluation of EMI emission. As it does not require full power operation it can be used for the testing of high power converters in anechoic chamber. An extensive experimental and theoretical characterization has been performed on the radiated noise of IGBT modules in inverter for railway applications during inductive turn-on operation. Physical analysis of involved phenomena has been executed by introducing an appropriate IGBT model that takes into account the internal stray elements. The experimental and simulation results demonstrate the direct dependence of the radiated noise on the dv/dt voltage gradient, which is directly related to the di/dt current gradient, in turns on driving parameters