Performance evaluation of high-voltage 1.2 kV silicon carbide metal oxide semi-conductor field effect transistors for three-phase buck-type PWM rectifiers in aircraft applications

This study investigates the use of 1.2 kV silicon carbide (SIC) metal oxide semi-conductor field effect transistors (MOSFETs) against standard insulated gate bipolar transistors (IGBTs) for the practical implementation of a three-phase buck-type pulse width modulation (PWM) rectifier for aircraft power networks, showing the design details and the benefits attained. The two main performance targets when designing and building power converters for aircraft applications are high reliability followed by reduced weight. The low switching losses of the 1.2 kV SiC MOSFET allow the converter to switch at higher frequency, allowing lighter passive filters with reduced size, which significantly reduces the weight of the complete converter system. The three-phase buck-rectifier can be used in an aircraft power system as a pre-stage converter for two main different applications: either to generate the main dc network (+270 V) by adding a simple boost converter or to generate the isolated 28 V dc network by adding a dc/dc converter in conjunction with a high-frequency transformer. A 4.5 kW prototype has been specifically designed and built to demonstrate the performance and advantages of the SiC MOSFET implementation.