State of the Art 10 kV NMOS Transistors
ABSTRACT Rapidly improving 4 H-SiC material quality and a maturing MOS process/design have enabled the development of the largest 10 kV MOSFET to date and the first 10 kV n-IGBT capable of flowing 10 A and 4 A, respectively, with very low on- resistances. With 20 V on the gate, both devices have aVp~ 5V with a positive temperature coefficient for on-resistance that facilitates their use in a parallel configuration. Each device has its own advantages. The conductivity modulated n-IGBT offers higher current density operation (up to 100 A/cm ) while the majority carrier MOSFET offers extremely fast 5 kV switching with only 140 nsec of turn-off time and a manageable 160 W/cm of dissipated power at 20 kHz. These exciting results indicate that the 10 kV SiC NMOS switches may potentially revolutionize emerging high voltage, high frequency power electronics.
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ABSTRACT: This paper presents a current-source inverter suitable for high-voltage/high-power motor drives. This inverter uses thyristors as main switching devices and utilizes a zero-voltage-switching (ZVS) commutation circuit. It has the advantages of good motor power factor and self-startability. We have evaluated a test model of the proposed inverter and a motor and verified that the inverter operates at a motor power factor of one and that it can be started even when the motor speed is zero. Moreover, a six-phase synchronous motor was driven by two of these inverters; it was confirmed that they decreased the motor torque ripple and the harmonic component of the voltage source. In addition, we evaluated the operation of the ZVS commutation circuit by simulation and experiment and thus verified that turnoff loss depends mainly on the inductance of the ZVS commutation circuit and not on gate resistance. Moreover, when the switching device turns off the current, its voltage is almost zero. That is, even if the inductance is large, the peak voltage of the switching device is low and switching loss is small. Therefore, the ZVS commutation circuit can be easily composed because it does not need to be of low inductance. These results show that a large-capacity drive system can be easily achieved with the proposed inverter.IEEE Transactions on Industry Applications 11/2010; · 1.67 Impact Factor
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ABSTRACT: The majority carrier domain of power semiconductor devices has been extended to 10 kV with the advent of SiC MOSFETs and Schottky diodes. The devices exhibit excellent static and dynamic properties with encouraging preliminary reliability. Twenty-four MOSFETs and twelve Schottky diodes have been assembled in a 10 kV half H-bridge power module to increase the current handling capability to 120 A per switch without compromising the die-level characteristics. For the first time, a custom designed system (13.8 kV to 465/√3 V solid state power substation) has been successfully demonstrated with these state of the art SiC modules up to 855 kVA operation and 97% efficiency. Soft-switching at 20 kHz, the SiC enabled SSPS represents a 70% reduction in weight and 50% reduction in size when compared to a 60 Hz conventional, analog transformer.Energy Conversion Congress and Exposition (ECCE), 2011 IEEE; 10/2011