EMI disturbance in Double Galvanic Insulation Transformer for high voltage insulation- Application on multilevel converter for 10kV SiC Mosfet drivers

Actually, in locomotives operating at 50Hz or 162/3Hz, the power train is supplied by a heavy 25kV/3kV iron transformer. To reduce the weigh and volume of this system, a multilevel converter directly linked to the catenary, is intended to be developed based on multilevel techniques at medium frequency. So, each component of the power electronic system has to be insulated for a maximal voltage of 60kV (catenary transient maximal voltage). Particularly, the drivers´ system supply of the semiconductors must be insulated for this voltage too. Each driver need to be insulated for another voltage level: 10kV (Voltage level of mosfet SiC used for this application).To deal with this specific constraint, the “Double Galvanic Insulation Transformer” (DGIT) and an adapted supply were developed. This system was developed to supply SiC Mosfet drivers which particularity is the speed of these switch commutation. The result of this particularity is a high dv/dt. The goal of this study is to see with simulation and measurement the effect of all conducted disturbances acting on the DGIT and its power supply.