Implementation of AC Current-Sensor-Less Control and High-Frequency Modulation of an All-SiC Current Source Inverter

The deployment of high-frequency wide-band-gap semiconductors, such as silicon carbide MOSFETs, has renewed interest in current source inverters for advanced motor-drive systems. With higher power density and potential benefits for high-speed controllers, a high switching frequency requires high-performance digital processors. However, conventional modulation strategies derived from standard voltage-source inverters are not applicable, and precautions must be taken to prevent overvoltage and inter-phase short circuits through proper overlap and dead times. Previous studies have proposed a simplified ac current-sensor-less high-speed controller design using high switching frequency in both continuous and discrete time domains. This paper presents the physical hardware implementation and testing of this design.