Analysis of Power Losses within a SiC-MOSFET-Inverter with Passive dv/dt-Damping Network for Reduced Voltage Slopes at Inductive Loads

Abstract:
In this paper the optimized loss distribution of a single phase SiC-MOSFET-inverter in combination with a passive output filter network for drivetrain applications is analysed and discussed. Three methods to reduce the voltage slopes at the load and thereby decrease the electromagnetic emissions as well as minimize the stress of both the winding insulation and the bearings are investigated. The voltage slope reduction is necessary to fit the requirements of electric machines and to increase the lifetime of the insulation. However, slower slew rates add additional switching losses to the system. The use of a passive dv=dt-damping network can be beneficial to shift some switching losses inside the filter instead of completely slowing down the switching speed of the semiconductors.