Design of an inverter for high-speed synchronous generators using SiC FETs

Existing inverter designs are not well-suited for use with high-speed generators due to the IGBTs used as switching elements, which are not fast enough. SiC FETs offer a lower switching time compared to IGBTs, which is key to working with high-frequency machines. However, getting a faster inverter is not as simple as replacing IGBTs with SiC FETs. The system must be adapted, and every component from the gate drivers to the control circuitry, including the sensing elements and power supply must be evaluated against new requirements. From higher frequencies also arise a number of issues related to EMC/EMI, making the PCB layout a crucial component of the inverter. The complete system can be split in two different circuits: the power or drive circuit, and the control circuit. Due to their differences in purpose, power requirements and the generally low ruggedness of most of the control side components, the two circuits must be electrically isolated from each other, but still be able to communicate.