Performance Evaluation of 10 kV SiC Current Switch Based PWM Current Source Inverter for 4.16 kV Motor Drive Applications

Series-connected 6.5 kV symmetric gate-commutated thyristor (SGCTs) are widely used as the reverse blocking switch (referred to as the current switch in this paper) in 4.16 kV PWM current source inverter (CSI) based motor drive applications up to 420 Hz switching frequency. Modern 10 kV SiC MOSFETs and SiC diodes have the potential to be implemented as the current switch with lower switching loss and a smaller count of the active switches in the 4.16 kV CSI-based drives. In this paper, a 10 kV SiC current switch is presented to enable a medium voltage (MV) PWM-CSI for 4.16 kV motor drive applications. The higher switching frequency capability of the 10 kV SiC current switch reduces the output current harmonics and the dc link inductor size significantly. Experimental tests have shown that the electrical and thermal performance of the 10 kV SiC current switch-based CSI is shown to be reasonably acceptable and near to 10 kV SiC MOSFET-based VSI drives at 10 kHz switching frequency.