Design, Development and Control of >13kV Silicon-Carbide MOSFET based Solid State Transformer(SST) Authors:Wang, Gangyao North Carolina State University

Design, Development and Control of >13 kV Silicon-Carbide MOSFET based Solid
State Transformer (SST) by Gangyao Wang
A dissertation submitted to the Graduate Faculty of North Carolina State University
in partial fulfillment of the requirements for the Degree of Doctor of Philosophy
Electrical Engineering
Raleigh, North Carolina
2013 
ABSTRACT

WANG, GANGYAO. Design, Development and Control of >13 kV Silicon-Carbide MOSFET based Solid State Transformer (SST). (Under the direction of Dr. Alex Huang.)

Within the advent of the smart grid system, the solid state transformer (SST) will replace the traditional 60 Hz transformer formed by silicon steel core and copper windings and provides the interface between the high distribution voltage and low utility voltage. Other than the smaller size and less weight, SST also brings many more functionalities including voltage regulation, reactive power compensation, power management and renewable energy integration. The motivation of this research is to design a solid state transformer based on the wide band-gap Silicon Carbide (SiC) power MOSFETs and compare it with the silicon IGBT based SST. With wider band-gap and higher critical electrical field, the high voltage SiC power device has advantages over silicon power device for both conduction and switching. An extensive study and characterization of the SiC MOSFET was first carried out. It has been found that the MOSFET parasitic capacitors store significant amount of energy and the MOSFET turn on loss is high but turn off loss is virtually zero with small enough turn on gate resistor. A method for estimating the MOSFET parasitic capacitances has been proposed and explained in detail. A PLECS loss simulation model has been developed for the >13 kV SiC MOSFET which has been verified through a boost converter with the SiC MOSFET switches under 40 kHz for both soft switching and hard switching conditions separately.
WEBSITE ORIGINAL
http://repository.lib.ncsu.edu/ir/handle/1840.16/9163
LINK DIRECT
http://repository.lib.ncsu.edu/ir/bitstream/1840.16/9163/1/etd.pdf
LINK ALTERNATIVO
https://copy.com/daXOYRg2bHliBDCU