Date of Award

2020

Document Type

Dissertation

Degree Name

Ph.D.

Department

Electrical Engineering

First Advisor

Mohammad Matin

Second Advisor

Shimelis Assefa

Third Advisor

David Wenzhong Gao

Keywords

Converter efficiency, Power electronics, Renewable energy, SiC Power devices, Silicon carbide (SiC), Wide bandage (WBG) semiconductors

Abstract

Enhancing the performance and efficiency of power converter systems requires fast-switching power devices with considerably low switching and conduction losses. Silicon (Si) semiconductor devices are the essential components in electronic converter designs, and their behaviors and switching characteristics determine the system’s overall performance and efficiency. These conventional Si devices are nearing to hit their physical and operational limits in meeting power converter requirements with respect to high temperature and large voltage conditions. However, silicon carbide (SiC) power devices enable greater converter efficiency and better power density, particularly under hard switching frequencies and high output voltages due to their outstanding material properties, including lower on-state resistance, higher electric field, and wider energy bandgap. This research focuses on emerging SiC semiconductor devices in dc-dc electronic converters to maximize system efficiencies, improve power densities, and overcome the existing limitations of Si technology. The aim of this research is to examine switching behaviors of SiC-based semiconductors, especially at a 650 V blocking voltage range, and to demonstrate their impact on power converter performance. This experimental research investigates and compares the device behaviors of the SiC cascode JFET and SiC MOSFET with Si IGBT and Si MOSFET devices at a similar voltage and current ratings. The switching behaviors of each device technologies are demonstrated at different parameters, and the switching energy losses under various voltages and currents are experimentally evaluated in detail using a double-pulse test (DPT). The switching voltage and current derivatives for each transistor are illustrated as well. Finally, SiC-based converters are examined at different frequency levels, input voltages, and load conditions to fully test and explore the converter design with SiC diodes and transistors with respect to semiconductor loss, overall efficiency, and converter size and cost. Thus, this research will validate the superior switching performance of 650 V SiC power devices and show significantly improved overall efficiency in the SiC-based converters.

Publication Statement

Copyright is held by the author. User is responsible for all copyright compliance.

Provenance

Received from ProQuest

Rights holder

Saleh Salem H. Alharbi

File size

144 p.

File format

application/pdf

Language

en

Discipline

Electrical engineering, Energy

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