Power Electronics for Medium Voltage Applications

Due to the large band gap and high breakdown field strength of silicon carbide, transistors with an extremely high blocking voltage of up to 15 kV can be made using this material. These components make totally new applications possible for power electronics in the medium voltage range for voltages up to 20 kV. Due to the low switching and conduction losses of the devices, switching frequencies that are up to 10 times higher than comparable circuits with series connected Si-IGBTs can be achieved. As a result, the complexity of the circuitry as well as the dimensions of the inductive devices like inductors and transformers can be greatly reduced.

In the medium voltage range, compact and efficient DC/DC converters can be built with and without galvanic separation. Through the potential of high frequencies, new possibilities are created, e.g., switching with medium-frequency transformers. One and three phase inverters can be operated directly in the medium voltage range, giving them new possibilities of application.