Engineering Commons^™

High-Power Power Conditioning Systems For Medium-Voltage Applications, Ahmed Rahouma Fares Rahouma

Graduate Theses and Dissertations

The purpose of this dissertation is to address the background, theoretical analyses, design methodologies, and evaluation techniques relevant to high-power power conditioning systems (PCSs) tailored for medium-voltage (MV) applications. Conventional PCSs, reliant on line-frequency transformers (LFTs), suffer from many problems including low power densities, inflexible designs, and scalability constraints. Employing multilevel converters (MLCs), particularly cascaded H-bridge topology, eliminates the need for these LFTs. A key focus lies in minimizing the number of cascaded building blocks by harnessing MV power switching modules. The dissertation makes two primary contributions: firstly, it offers a design methodology for MV-PCS, facilitating the selection of the …

A 4-Switch Buck-Boost Dc/Dc Converter For Electric Vehicle Applications, Andrew Hudak, Ashley Schiller

Electrical Engineering

In this project, we develop a four switch buck-boost DC/DC converter that is to be integrated into a microgrid-inspired power distribution architecture for electric vehicles. The overall architecture includes DC/DC and DC/AC converters for bi-directional energy transfer between the DC and AC ports along with a communications port to control each energy interface. There is also the onboard battery and the internal combustion engine power exchange being done with DC/DC converters and AC/DC inverters to connect to the centralized DC bus. Hardware prototypes using an Arduino and Raspberry Pi for the 500 W DC/DC and DC/AC converters have been previously …

Dynamic Modeling And Control Of A Solid State Semiconductor-Based Transformer, Microgrid And Storage Systems, Rubén Darío Viñán-Velasco

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

Smart Grids are power grid models designed with the idea of including the growing new technologies, from generation to storage devices, and are a response to the growing demands from consumers and the presence of electronic components being commonplace in the modern devices. The design requires a dynamic alternative in order to build an independent grid that can also work in cooperation with other micro-grids and the power grid in an integrated way. Smart-grids present several advantages over the traditional power grid scheme, but the economic costs of the components required to implement smart-grids is currently a great limitation. This …

Fourier Analysis And Optimization Of Inductive Wireless Power Transfer For Electric Vehicle Charging, Andrew P. Foote

Doctoral Dissertations

With the growth of electric vehicle (EV) popularity, different charging options to increase user convenience and reduce charging time such as high power wireless charging are increasingly being developed and researched. Inductive wireless power transfer (WPT) systems for EVs must meet specifications such as stray field, battery power and voltage operating range, efficiency, and ground clearance. The coil geometry and design have a large impact in meeting these constraints. Typical design approaches include iterative analysis of predetermined coil geometries to identify candidates that meet these constraints.

This work instead directly generates WPT coil shapes and magnetic fields to meet specifications …

Design Of Hybrid Inverters Using Wideband Gap Semiconductors For Microgrid Application, Luca Gacy

Electronic Theses and Dissertations

As the world becomes more reliant on renewable energy sources such as solar and wind power, the need for high efficiency high power inverters connected to homes is more relevant than ever. Connecting these renewable energy sources (RES) coupled with an energy storage system (ESS) to the grid through a hybrid inverter, with the highest efficiency and grid stability, is quickly becoming a necessity for the near future. This thesis explores the integration of wide band gap semiconductors for the power stage in these systems, along with the analysis of hybrid inverter topologies and structures. The goal of this thesis …

Design And Implementation Of High-Efficiency, Lightweight, System-Friendly Solid-State Circuit Breaker, Dehao Qin

All Dissertations

Direct current (DC) distribution system has shown potential over the alternative current (AC) distribution system in some application scenarios, e.g., electrified transportation, renewable energy, data center, etc. Because of the fast response speed, DC solid-state circuit breaker (SSCB) becomes a promising technology for the future power electronics intensive DC energy system with fault-tolerant capability. First, a thorough literature survey is performed to review the DC-SSCB technology. The key components for DC-SSCB, including power semiconductors, topologies, energy absorption units, and fault detection circuits, are studied. It is observed that the prior studies mainly focus on the basic interruption capability of the …

Design Approaches To Enhance Power Density In Power Converters For Traction Applications, Shamar Christian

Graduate Theses and Dissertations

This dissertation presents a design strategy to increase the power density for automotive Power Conversion Units (PCUs) consisting of DC-DC and DC-AC stages. The strategy significantly improves the volumetric power density, as evident by a proposed PCU constructed and tested having 55.6 kW/L, representing an 11.2 % improvement on the Department of Energy’s 2025 goal of 50 kW/L for the same power electronics architecture. The dissertation begins with a custom magnetic design procedure, based on optimization of a predetermined C-core geometrical relationship and custom Litz wire. It accounts for electrical and thermal tradeoffs to produce a magnetic structure to best …

Power Quality Control And Common-Mode Noise Mitigation For Inverters In Electric Vehicles, Yang Huang

Doctoral Dissertations

Inverters are widely utilized in electric vehicle (EV) applications as a major voltage/current source for onboard battery chargers (OBC) and motor drive systems. The inverter performance is critical to the efficiency of EV system energy conversion and electronics system electro-magnetic interference (EMI) design. However, for AC systems, the bandwidth requirement is usually low compared with DC systems, and the control impact on the inverter differential-mode (DM) and common-mode (CM) performance are not well investigated. With the wide-band gap (WBG) device era, the switching capability of power electronics devices drastically improved. The DM/CM impact that was brought by the WBG device-based …

Analysis And Optimization Of The Two-Phase Series Capacitor Buck Dc-Dc Converter, Salahaldein Ali Aboajila Ahmed

Graduate Theses and Dissertations

Current sharing schemes for conventional multi-phase converters are based on sensing each phase current to deliver the current information to their controllers. In conventional buck converters, this fact may require a preset current sharing ratio at the expense of efficiency, which eventually requires a larger sensing circuit to achieve the sensing accuracy of each phase. Introducing the concept of automatic current sharing is one of the solutions to tackle this issue. Automatic current sharing (Current Sharing Mechanism CSM) is an advanced way to distribute heat generation in multi-phase switching topologies at full load. A two-phase series capacitor buck converter (2-pscB) …

Power Line Coupling Power Supply Design, Janine Gian Christii C. Darato, Jeni K. Kawate, Nicholas A. Marta

Electrical Engineering

In this project, a power supply was designed for a startup company, Perch Sensing, to detect wildfires with the use of distributed sensors across power lines. The purpose of the power supply is to provide 15W of power to a microcontroller, which controls the sensor nodes. The power supply hangs from power lines and draws energy by inductively coupling to these lines. Our design starts with a current transformer that steps down the current from the power line, which is fed into a shunting mechanism as a safety precaution when the load is absent, then to the power supply itself. …

Special Power Electronics Converters And Machine Drives With Wide Band-Gap Devices, Yibin Zhang

Theses and Dissertations--Electrical and Computer Engineering

Power electronic converters play a key role in power generation, storage, and consumption. The major portion of power losses in the converters is dissipated in the semiconductor switching devices. In recent years, new power semiconductors based on wide band-gap (WBG) devices have been increasingly developed and employed in terms of promising merits including the lower on-state resistance, lower turn-on/off energy, higher capable switching frequency, higher temperature tolerance than conventional Si devices. However, WBG devices also brought new challenges including lower fault tolerance, higher system cost, gate driver challenges, and high dv/dt and resulting increased bearing current in electric machines.

This …

Developing A Medium-Voltage Three-Phase Current Compensator Using Modular Switching Positions, Vinson Jones

Graduate Theses and Dissertations

The objective of this thesis is to present the context, application, theory, design, construction, and testing of a proposed solution to unbalanced current loading on three-phase four-wire systems. This solution, known as the Medium-Voltage Unbalanced Current Static Compensator or MV-UCSC, is designed to recirculate currents between the three phases of adistribution system. Through this redistribution of the currents negative- and zero-sequence current components are eliminated and a balanced load is seen upstream from the point of installation. The MV-UCSC as it operates in the distribution system is presented followed by its effect on traditional compensation equipment. The construction of the …

Survey Of Dc-Dc Non-Isolated Topologies For Unidirectional Power Flow In Fuel Cell Vehicles, Mahajan Sagar Bhaskar, Vigna K. Ramachandaramurthy, Sanjeevikumar Padmanaban, Frede Blaabjerg, Dan M. Ionel, Massimo Mitolo, Dhafer Almakhles

Power and Energy Institute of Kentucky Faculty Publications

The automobile companies are focusing on recent technologies such as growing Hydrogen (H2) and Fuel Cell (FC) Vehicular Power Train (VPT) to improve the Tank-To-Wheel (TTW) efficiency. Benefits, the lower cost, `Eco' friendly, zero-emission and high-power capacity, etc. In the power train of fuel cell vehicles, the DC-DC power converters play a vital role to boost the fuel cell stack voltage. Hence, satisfy the demand of the motor and transmission in the vehicles. Several DC-DC converter topologies have proposed for various vehicular applications like fuel cell, battery, and renewable energy fed hybrid vehicles etc. Most cases, the DC-DC power converters …

Modeling And Optimization Algorithm For Sic-Based Three-Phase Motor Drive System, Ren Ren

Doctoral Dissertations

More electric aircraft (MEA) and electrified aircraft propulsion (EAP) becomes the important topics in the area of transportation electrifications, expecting remarkable environmental and economic benefits. However, they bring the urgent challenges for the power electronics design since the new power architecture in the electrified aircraft requires many benchmark designs and comparisons. Also, a large number of power electronics converter designs with different specifications and system-level configurations need to be conducted in MEA and EAP, which demands huge design efforts and costs. Moreover, the long debugging and testing process increases the time to market because of gaps between the paper design …

Study Of A Symmetrical Llc Dual-Active Bridge Resonant Converter Topology For Battery Storage Systems, John K. George

Graduate Theses and Dissertations

A symmetrical LLC resonant converter topology with a fixed-frequency quasi-triple phase-shift modulation method is proposed for battery-powered electric traction systems with extensions to other battery storage systems. Operation of the converter with these methods yields two unique transfer characteristics and is dependent on the switching frequency. The converter exhibits several desirable features: 1) load-independent buck-boost voltage conversion when operated at the low-impedance resonant frequency, allowing for dc-link voltage regulation, zero-voltage switching across a wide load range, and intrinsic load transient resilience; 2) power flow control when operated outside the low-impedance resonance for integrated battery charging; 3) and simple operational mode …

Cybersecurity Methods For Grid-Connected Power Electronics, Stephen Joe Moquin

Graduate Theses and Dissertations

The present work shows a secure-by-design process, defense-in-depth method, and security techniques for a secure distributed energy resource. The distributed energy resource is a cybersecure, solar inverter and battery energy storage system prototype, collectively called the Cybersecure Power Router. Consideration is given to the use of the Smart Green Power Node for a foundation of the present work. Metrics for controller security are investigated to evaluate firmware security techniques. The prototype's ability to mitigate, respond to, and recover from firmware integrity degradation is examined. The prototype shows many working security techniques within the context of a grid-connected, distributed energy resource. …

Experimental Investigation Of Low-Voltage Silicon Carbide (Sic) Semiconductor Devices For Power Conversion Applications, Saleh Salem H. Alharbi

Electronic Theses and Dissertations

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 …

Design And Optimization Of A High Power Density Silicon Carbide Traction Inverter, Tyler Adamson

Graduate Theses and Dissertations

This project was initiated with the goal of demonstrating a 3-phase silicon carbide based 150-kW 25 kW/L DC-AC power conversion unit capable of operation with coolant temperatures up to 90°C. The project goals were met and exceeded by first analyzing the established inverter topologies to find which one would yield the highest power density while still meeting electrical performance needs in the 150-kW range. Following topology selection, the smallest silicon carbide power module that met the electrical requirements of the system was found through experimental testing and simulation. After a power module selection was finalized, a DC link capacitor bank …

Split Dc Bus Converters For Power Electronic And Ac-Dc Microgrid Applications, Javad Khodabakhsh

Electronic Thesis and Dissertation Repository

Power electronic converters are used extensively for electrical power conversion in applications such as renewable energy systems, utility applications, and electric vehicles. Such converters are needed as it is rare for a source voltage to fit the needs of a load or a set of loads for any particular application. They consist of active semiconductor switches and passive components that are combined in circuit structures (topologies) that are operated with a control strategy. The focus of this thesis is on AC-DC and DC-DC converters and their applications in AC-DC microgrids.

AC-DC converters are typically two-stage converters that consist of a …

Local And Central Controllers For Microgrids, Edgar Ariel Escala Calame

Graduate Theses and Dissertations

The main objective of this thesis is to serve as a guide, so readers are able to learn about microgrids and to design simple controllers for different AC microgrid applications. In addition, this thesis has the objective to provide examples of simulation cases for the hierarchical structure of a basic AC microgrid which can be used as a foundation to build upon, and achieve more complex microgrid structures as well as more sophisticated power-converter control techniques.

To achieve these objectives, the modeling of voltage source converters and control design in the z-domain are presented. Moreover, the implementation and transient analysis …

Investigating Efficiency Of Ac Direct Drive Of Led Lighting, Miles Davis Head

Electrical Engineering

This project explores the rapidly-expanding area of AC direct drive for LED lighting. AC LED driving does not use typical DC-DC converter-based driving but uses semiconductor switches and a linear regulator to activate a number of LEDs proportional to the input voltage at any given time. This allows bulky, expensive magnetics to be eliminated from the system. The goal of this project was to develop a flexible simulation of a common AC LED system to find areas of significant power loss and attempt to improve them. This allows future versions of an AC LED system to start with major loss …

Scada And Plc Systems Configuration For The Ncrept Test Facility, Arman Ahmed

Electrical Engineering Undergraduate Honors Theses

This thesis details the project to update the control and interface system of the National Center for Reliable Electric Power Transmission (NCREPT) testing facility. The need for this project arose from the 2017-2018 expansion of the facility, which included some modifications in the layout of electrical equipment used for testing purposes. These modifications necessitated the update of the control and interface system. Additionally, the old system was implemented a decade ago and is nearing obsolescence, so the facility’s expansion served as an opportune time for an upgrade.

There were two main parts to the scope of this project, which were …

Design Of Dc-Link Vscf Ac Electrical Power System For The Embraer 190/195 Aircraft, Eduardo Francis Carvalho Freitas, Nihad E. Daidzic

Journal of Aviation Technology and Engineering

A proposed novel DC-Link VSCF AC-DC-AC electrical power system converter for Embraer 190/195 transport category airplane is presented. The proposed converter could replace the existing conventional system based on the CSCF IDGs. Several contemporary production airplanes already have VSCF as a major or backup source of electrical power. Problems existed with the older VSCF systems in the past; however, the switched power electronics and digital controllers have matured and can be now, in our opinion, safely integrated and replace existing constant-speed hydraulic transmissions powering CSCF AC generators. IGBT power transistors for medium-level power conversion and relatively fast efficient switching are …

Thermal Characterization Of Magnetic Components, Jiazhou Zhong, Veda Samhitha Duppalli, Scott D. Sudhoff Professor

The Summer Undergraduate Research Fellowship (SURF) Symposium

Thermal limits are crucial constraints in the design of power magnetic components. As the power density of magnetic components continues to increase, cooling becomes more critical. Our research focuses on solving for the amount of cooling needed for a particular magnetic component. During the research process, a low-velocity wind tunnel designed and built from the ground up is used to form uniform and controlled conditions for the test components. Thermal Equivalent Circuit (TEC) and parameter identification techniques are used in conjunction to yield temperature distribution results. The expected result is temperature data on various areas of the component under different …

Battery Energy Storage Emulation For Power System Applications, Jessica Danielle Boles

Masters Theses

The concept of energy storage for power systems has received increasingly more attention in recent decades, and the growing penetration of renewable energy sources has only escalated demand for it. Energy storage systems are excellent for balancing generation and load, for suppressing power fluctuations, and for providing other ancillary services to the grid. The Hardware Testbed (HTB) is a novel converter-based grid emulator created for studying the needs associated with high renewable penetration, but the system currently lacks a battery storage emulator. Thus, this work documents the development of a battery energy storage system (BESS) emulator for the HTB.

The …

High-Current Integrated Battery Chargers For Mobile Applications, Gabriel Alejo Gabian

Masters Theses

Battery charging circuits for mobile applications, such as smart phones and tablets, require both small area and low losses. In addition, to reduce the charging time, high current is needed through the converter. In this work, exploration of the Buck, the 3-Level Buck and the Hybrid Buck converter is performed over the input voltage, the total FET area and the load current. An analytical loss model for each topology is constructed and constrated by experimental results. In addition, packaging and bond wire impact on on-chip losses is analyzed by 3D modeling. Finally, a comparison between the topologies is presented determining …

Automatic Standby Power-Saving Power Strip, Trung Nguyen

Electrical Engineering

The Standby Power Saving Power Strip improves on common power strip functionality. The project reduces the power loss from most electrical devices’ standby power mode, while retaining the convenience of leaving the devices plugged-in. The surge protector automatically recognizes when the plugged-in devices enter standby power mode. Then, it shuts off power to that device and automatically provides power back to the plugged-in devices, when turned on.

Design And Construction Of 1800w Modular Multiple Input Single Output Non-Isolated Dc-Dc Converters, Angelo Miguel Asuncion Gallardo

Master's Theses

This thesis report details the design and construction of non-isolated DC-DC converters to create a Multiple Input Single Output (MISO) converter for combining multiple renewable energy sources into one single output. This MISO uses the four-switch buck-boost topology to output a single 48V from multiple nominal 24V inputs. The MISO converter implements a modular approach to deliver 1800W output power. Each module in the MISO is rated at 600W and they share the output power equally. Hardware results show that the converter produces 1800W of output power from three sources with 96.4% efficiency. Each module also demonstrates equal sharing feature …

Minimum Time Control Of Paralleled Boost Converters, Shishir Patel

Dissertations, Master's Theses and Master's Reports

Demand for electrification is booming in both, traditional and upcoming generations of technological advancements. One of the constituent blocks of these electrified systems is Power conversion. Power conversion systems are often constructed by paralleling multiple power converter blocks for high performance and reliability of overall system. An advanced control technique is developed with an aim to optimize system states of heterogeneous power converters within minimum time while maintaining feasible stress level on individual power converter blocks. Practical implementation of real-time controller and performance improvement strategies are addressed. Experimental results validating high performance control scheme, and sensitivity analysis of system states …

Simulation, Measurement, And Emulation Of Photovoltaic Modules Using High Frequency And High Power Density Power Electronic Circuits, Yunas Erkaya

Electrical & Computer Engineering Theses & Dissertations

The number of solar photovoltaic (PV) installations is growing exponentially, and to improve the energy yield and the efficiency of PV systems, it is necessary to have correct methods for simulation, measurement, and emulation. PV systems can be simulated using PV models for different configurations and technologies of PV modules. Additionally, different environmental conditions of solar irradiance, temperature, and partial shading can be incorporated in the model to accurately simulate PV systems for any given condition.

The electrical measurement of PV systems both prior to and after making electrical connections is important for attaining high efficiency and reliability. Measuring PV …