Engineering Commons^™

High-Performance Wide Bandgap Semiconductor Power Modules Enabled By Advanced Two-Phase Mini-Channel Cooling, Bo Tian

Theses and Dissertations

There is a widespread need for high performance wide bandgap power modules in both commercial and military applications. However, given the rapid advancements of wide bandgap power module technology, conventional cooling solutions have not kept up and do not provide the thermal management performance needed for high power density. Based on the two-phase cooling approach, two-phase microchannels operating at low fluid flow rates with low pressure drops have huge potential in enabling higher power density applications. Several studies have illustrated the potential great advantages of two-phase cooling compared to single-phase cooling in terms of maximum device temperature, spatial thermal distribution …

High Frequency Injection Sensorless Control For A Permanent Magnet Synchronous Machine Driven By An Fpga Controlled Sic Inverter, Jared Walden

Masters Theses

As motor drive inverters continue to employ Silicon Carbide (SiC) and Gallium Nitride (GaN) devices for power density improvements, sensorless motor control strategies can be developed with field-programmable gate arrays (FPGA) to take advantage of high inverter switching frequencies. Through the FPGA’s parallel processing capabilities, a high control bandwidth sensorless control algorithm can be employed. Sensorless motor control offers cost reductions through the elimination of mechanical position sensors or more reliable electric drive systems by providing additional position and speed information of the electric motor. Back electromotive force (EMF) estimation or model-based methods used for motor control provide precise sensorless …

Direct Torque Control For Silicon Carbide Motor Drives, Mohammad Hazzaz Mahmud

Graduate Theses and Dissertations

Direct torque control (DTC) is an extensively used control method for motor drives due to its unique advantages, e.g., the fast dynamic response and the robustness against motor parameters variations, uncertainties, and external disturbances. Using higher switching frequency is generally required by DTC to reduce the torque ripples and decrease stator current total harmonic distortion (THD), which however can lower the drive efficiency. Through the use of the emerging silicon carbide (SiC) devices, which have lower switching losses compared to their silicon counterparts, it is feasible to achieve high efficiency and low torque ripple simultaneously for DTC drives.

To overcome …

Memory Module Design For High-Temperature Applications In Sic Cmos Technology, Affan Abbasi

Graduate Theses and Dissertations

The wide bandgap (WBG) characteristics of SiC play a significant and disruptive role in the power electronics industry. The same characteristics make this material a viable choice for high-temperature electronics systems. Leveraging the high-temperature capability of SiC is crucial to automotive, space exploration, aerospace, deep well drilling, and gas turbines. A significant issue with the high-temperature operation is the exponential increase in leakage current. The lower intrinsic carrier concentration of SiC (10-9 cm-3) compared to Si (1010 cm-3) leads to lower leakage over temperature. Several researchers have demonstrated analog and digital circuits designed in SiC. However, a memory module is …

Reducing Emi In Sic Direct Torque Controlled Motor Drive, Michael Sykes

Electrical Engineering Undergraduate Honors Theses

This paper covers the comparison between Silicon (Si) vs Silicon Carbide (SiC) for Motor Drive systems and a possible control algorithm to limit the increased Electromagnetic Interference (EMI) caused by using SiC transistors for the inverter. Motor Drive systems need constant improvements if the world is going to move on from machines that emit CO₂ and other harmful gases into the Earth’s atmosphere. One reason these electric machines are not commonplace today is because of their efficiency and other problems they may cause. Silicon transistors are the most commonplace transistor around the world today, but advances over the past …

Simultaneous Ohmic Contacts To N And P-Type Silicon Carbide For Future Electric Vehicles, Hayden Hunter

Electrical Engineering Undergraduate Honors Theses

The paper explores possible metallization schemes to form simultaneous ohmic contacts to n-type and p-type silicon carbide contacts. Silicon carbide has shown promise in revolutionizing the power electronics market due to its increased switching speed, compact design, and higher temperature tolerance when compared to Silicon, the market standard. With the continuing development of silicon carbide technology, higher efficiency in future electric vehicles can be achieved by employing this new technology. This paper discusses theoretical contact formation between metals and semiconductors along with a proposed experiment to create a Ni/Al metallization scheme on both n and p-type contacts simultaneously on a …

Design And Simulation Of Power Electronics Modules, Haonan Jia

Graduate Theses and Dissertations

Silicon carbide (SiC), a wide-bandgap semiconductor material, greatly improves the performance of power semiconductor devices. Its electrical characteristics have a positive impact on the size, efficiency, and weight of the power electronics systems. Parasitic circuit elements and thermal properties are critical to the power electronics module design. This thesis investigates the various aspects of layout design, electrical simulation, thermal simulation, and peripheral design of SiC power electronic modules. ANSYS simulator was used to design and simulate the power electronic modules. The parasitic circuit elements of the power module were obtained from the device parameters given in the datasheet of these …

Synthesis Of Graphene Using Plasma Etching And Atmospheric Pressure Annealing: Process And Sensor Development, Andrew Robert Graves

Graduate Theses, Dissertations, and Problem Reports

Having been theorized in 1947, it was not until 2004 that graphene was first isolated. In the years since its isolation, graphene has been the subject of intense, world-wide study due to its incredibly diverse array of useful properties. Even though many billions of dollars have been spent on its development, graphene has yet to break out of the laboratory and penetrate mainstream industrial applications markets. This is because graphene faces a ‘grand challenge.’ Simply put, there is currently no method of manufacturing high-quality graphene on the industrial scale. This grand challenge looms particularly large for electronic applications where the …

Design And Evaluation Of High Efficiency Power Converters Using Wide-Bandgap Devices For Pv Systems, Fahad Almasoudi

Electronic Theses and Dissertations

The shortage of fossil resources and the need for power generation options that produce little or no environmental pollution drives and motivates the research on renewable energy resources. Power electronics play an important role in maximizing the utilization of energy generation from renewable energy resources. One major renewable energy source is photovoltaics (PV), which comprises half of all recently installed renewable power generation in the world. For a grid-connected system, two power stages are needed to utilize the power generated from the PV source. In the first stage, a DCDC converter is used to extract the maximum power from the …

Gating Methods For High-Voltage Silicon Carbide Power Mosfets, Audrey Dearien

Graduate Theses and Dissertations

The objective of this thesis is to assess the challenges associated with driving Silicon Carbide (SiC) power devices, and to compare the potential gate drive methods for these devices which address those challenges. SiC power devices present many benefits that make them suitable for next generation automotive, power utility grid, and energy management applications. High efficiency, increased power density, and reliability at high-temperatures are some of the main benefits of SiC technology. However, the many challenges associated with these devices have prevented their adoption into industry applications. The argument is made in this thesis that the gate driver is a …

Design Considerations For Paralleling Multiple Chips In Sic Power Modules, Fei Yang

Masters Theses

With the benefits of fast switching speed, low on-resistance and high thermal conductivity, silicon carbide (SiC) devices are being implemented in converter designs with high efficiency and high power density. Consequently, SiC power modules are needed. However, some of the preestablished package designs for silicon based power modules are not suitable to manifest the advantages of SiC devices. Therefore, this thesis aims at optimizing the package design to utilize the fast switching capability of SiC devices.

First, the power loop parasitic inductance induced by the package can lead to large voltage spikes with the fast switching SiC device. It can …

Compact Modeling Of Sic Insulated Gate Bipolar Transistors, Sonia Perez

Graduate Theses and Dissertations

This thesis presents a unified (n-channel and p-channel) silicon/silicon carbide Insulated Gate Bipolar Transistor (IGBT) compact model in both MAST and Verilog-A formats. Initially, the existing MAST model mobility equations were updated using recently referenced silicon carbide (SiC) data. The updated MAST model was then verified for each device tested. Specifically, the updated MAST model was verified for the following IGBT devices and operation temperatures: n-channel silicon at 25 ˚C and at 125 ˚C; n-channel SiC at 25 ˚C and at 175 ˚C; and p-channel SiC at 150 ˚C and at 250 ˚C. Verification was performed through capacitance, DC output …

Sic Band Gap Voltage Reference For Space Applications, Charles Kenneth Roberts

Masters Theses

Electronics for space applications can experience wide temperature swings depending on orientation towards stars and duty cycle of propulsion systems. Energy on satellites primarily comes from radiological thermal generators and / or solar panels. This requires space electronic applications to be energy efficient and have high temperature tolerance. As a result, space electronic systems use high efficiency SMPS [switching mode power supplies].

Currently, there exists SiC [silicon carbide] based electronics that is state of the art for high temperature applications. Commercial manufacturers at this time produce SiC Power MOSFETs [Metal Oxide Semiconductor Field Effect Transistors], which are the switching element …

Characterization And Realization Of High Switching-Speed Capability Of Sic Power Devices In Voltage Source Converter, Zheyu Zhang

Doctoral Dissertations

The emerging wide band-gap, silicon carbide (SiC) power devices greatly improve the switching performance due to their inherent fast switching capability. However, the high switching-speed performance makes their switching behavior become more susceptible to parasitics of the application circuit. In the end, unlike the excellent switching performance of SiC devices tested in manufacturer’ datasheets, the observed switching performance in actual power converters is almost always worse. This dissertation aims at characterization and realization of high switching-speed capability of SiC devices in one of the most widely used converter types, the voltage source converter (VSC).

To evaluate the fast dynamic characteristics …

High-Efficiency Three-Phase Current Source Rectifier Using Sic Devices And Delta-Type Topology, Ben Guo

Doctoral Dissertations

In this dissertation, the benefits of the three-phase current source rectifier (CSR) in high power rectifier, data center power supply and dc fast charger for electric vehicles (EV) will be evaluated, and new techniques will be proposed to increase the power efficiency of CSRs.

A new topology, referred as Delta-type Current Source Rectifier (DCSR), is proposed and implemented to reduce the conduction loss by up to 20%. By connecting the three legs in a delta type on ac input side, the dc-link current in DCSR can be shared by two legs at the same time.

To increase the switching speed …

Sic For Advanced Biological Applications, Joseph Register

USF Tampa Graduate Theses and Dissertations

Silicon carbide (SiC) has been used for centuries as an industrial abrasive and has been

actively researched since the 1960's as a robust material for power electronic applications.

Despite being the first semiconductor to emit blue light in 1907, it has only recently been

discovered that the material has crucial properties ideal for long-term, implantable biomedical

devices. This is due to the fact that the material offers superior biocompatibility and

hemocompatibility while providing rigid mechanical and chemical stability. In addition, the material

is a wide-bandgap semiconductor that can be used for optoelectronics, light delivery, and optical

sensors, which is the …

All-Sic Three-Phase Converters For High Efficiency Applications, Fan Xu

Doctoral Dissertations

The dissertation aims to improve the efficiency of three-phase converters using SiC power devices.The methodology to design a high efficiency all-SiC three-phase converter is presented. Four aspects are included: SiC power device evaluation, power loop parasitics analysis, high efficiency current source rectifier, and paralleled current source rectifier system.

The SiC JFET and MOSFET are tested based on voltage source and current source structures respectively. The dissertation proposes a device switching test circuit based on current source topology to simulate current commutation processes. The circuit can evaluate the switching performance and calculate switching loss of a power device used in a …

Frequency Characterization Of Si, Sic, And Gan Mosfets Using Buck Converter In Ccm As An Application, Keshava Gopalakrishna

Browse all Theses and Dissertations

Present day applications using power electronic converters are focusing towards improving the speed, efficiency, and robustness. This led to the implementation of new devices in such converters where speed and efficiency are of concern. As silicon (Si) based power devices are approaching their operational performance limits with respect to speed, it is essential to analyze the properties of new devices, which are capable of replacing silicon based devices. Wide band-gap (WBG) semiconductor materials such as silicon carbide (SiC) and gallium nitride (GaN) are such materials, whose material properties show promising advantages for power electronic applications.

This thesis focuses on the …

Modeling Of Power Semiconductor Devices, Tanya Kirilova Gachovska

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

One of the requirements for choosing a proper power electronic device for a converter is that it must possess a low specific on-resistance. The specific on-resistance of a bipolar device is related to the base width and doping concentration of the lightly doped drift region. This means that the doping concentration and the width of the low-doped base region in a bipolar device must be carefully considered to achieve a desired avalanche breakdown voltage and on-resistance. In order to determine the technological parameters of a semiconductor device, a one dimensional analysis is used to calculate the minimum depletion layer width, …

Design And Control Of High Power Density Motor Drive, Dong Jiang

Doctoral Dissertations

This dissertation aims at developing techniques to achieve high power density in motor drives under the performance requirements for transportation system. Four main factors influencing the power density are the main objects of the dissertation: devices, passive components, pulse width modulation (PWM) methods and motor control methods.

Firstly, the application of SiC devices could improve the power density of the motor drive. This dissertation developed a method of characterizing the SiC device performance in phase-leg with loss estimation, and claimed that with SiC Schottky Barrier Diode the advantage of SiC JFET could benefit the motor drive especially at high temperature. …

Investigation Of Reactively Sputtered Silicon Carbon Boron Nitride (Sicbn) Thin Films For High Temperature Applications, Arun Vijayakumar

Electronic Theses and Dissertations

The increasing demand for efficient energy systems in the last decade has brought about the development of advanced sensor systems that utilize advance detection methods to help in preventive maintenance of these essential systems. These usually are needed in hard to access environments where conditions are extreme and unfit for human interaction. Thin film based sensors deposited directly on the surfaces exposed to harsh environments can serve as ideal means of measuring the temperature of the component during operation. They provide the basic advantage of proximity to the surface and hence accurate measurement of the surface temperature. The low mass …

Sic Schottky Diodes And Polyphase Buck Converters, Veda Prakash N. Galigekere

Browse all Theses and Dissertations

The turn-on characteristics of a SiC Schottky diode are analyzed theoretically, by simulation, and by experiment. The static characteristics of SiC Schottky diodes and Si junction diodes are analyzed for normal and high temperatures. The effects of diffusion capacitance and junction capacitance on the turn-off transition of SiC Schottky diode have been analyzed theoretically. The turn-off transition of a SiC Schottky barrier diode is analyzed by modeling the metal-semiconductor junction capacitance considering the linear and the non-linear effects. Behavior of the linear and the non-linear metal-semiconductor junction capacitance models are evaluated exper- imentally. The performance of SiC Schottky diodes is …