Computer Aided Design of Circuits for Power Controlling with the New Power Elements Mosfet and Sit

Progress in the field of semiconductor technology has enabled the development of new kinds of power devices. These elements offer the designer the opportunity to find new or better solutions for power electronic circuits. The circuit design with the new elements generally requires extensive experimental studies, especially if the converter or inverter is operating direct from A.C. mains supplies. An alternative is the computer aided circuit design using, electrical models. This paper presents models derived from the structure of MOSFET and SIT power elements. The models are tested by simulating pull down converters and the results are compared with practical investigations. Additionally such a simulation was used in order to study the switching process of a inverter bridge with Power MOSFETs. These examinations lead to the design of a new kind of snubber circuit. It reduces the reverse recovery current of the inner diode, so that the MOSFETs are only loaded with their maximum continous ratings. These models enable a better understanding of the power elements themselves, the circuits around the elements and the behaviour of the entire system. Finally, the CAD optimization of the system is possible and could reduce costly hardware experiments.