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ASU Electronic Theses and Dissertations


This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.

In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.

Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.


Date Range
2015 2018


Presently, hard-switching buck/boost converters are dominantly used for automotive applications. Automotive applications have stringent system requirements for dc-dc converters, such as wide input voltage range and limited EMI noise emission. High switching frequency of the dc-dc converters is much desired in automotive applications for avoiding AM band interference and for compact size. However, hard switching buck converter is not suitable at high frequency operation because of its low efficiency. In addition, buck converter has high EMI noise due to its hard-switching. Therefore, soft-switching topologies are considered in this thesis work to improve the performance of the dc-dc converters. Many soft-switching ...

Contributors
Nan, Chenhao, Ayyanar, Raja, Bakkaloglu, Bertan, et al.
Created Date
2016

After a major disturbance, the power system response is highly dependent on protection schemes and system dynamics. Improving power systems situational awareness requires proper and simultaneous modeling of both protection schemes and dynamic characteristics in power systems analysis tools. Historical information and ex-post analysis of blackouts reaffirm the critical role of protective devices in cascading events, thereby confirming the necessity to represent protective functions in transient stability studies. This dissertation is aimed at studying the importance of representing protective relays in power system dynamic studies. Although modeling all of the protective relays within transient stability studies may result in a ...

Contributors
Hedman, Mojdeh Khorsand, Vittal, Vijay, Ayyanar, Raja, et al.
Created Date
2017

Distributed energy resources have experienced dramatic growth and are beginning to support a significant amount of customer loads. Power electronic converters are the primary interface between the grid and the distributed energy resources/storage and offer several advantages including fast control, flexibility and high efficiency. The efficiency and the power density by volume are important performance metrics of a power converter. Compact and high efficiency power converter is beneficial to the cost-effectiveness of the converter interfaced generations. In this thesis, a soft-switching technique is proposed to reduce the size of passive components in a grid-connected converter while maintaining a high power ...

Contributors
Yu, Ziwei, Ayyanar, Raja, Vittal, Vijay, et al.
Created Date
2018

Due to the increasing trend of electricity price for the future and the price reduction of solar electronics price led by the policy stimulus and the technological improvement, the residential distribution solar photovoltaic (PV) system’s market is prosperous. Excess energy can be sold back to the grid, however peak demand of a residential customer typically occurs in late afternoon/early evening when PV systems are not a productive. The solar PV system can provide residential customers sufficient energy during the daytime, even the exceeding energy can be sold back to the grid especially during the day with good sunlight, however, the ...

Contributors
Wang, Xinan, Karady, George G, Smedley, Grant, et al.
Created Date
2016

The most important metrics considered for electric vehicles are power density, efficiency, and reliability of the powertrain modules. The powertrain comprises of an Electric Machine (EM), power electronic converters, an Energy Management System (EMS), and an Energy Storage System (ESS). The power electronic converters are used to couple the motor with the battery stack. Including a DC/DC converter in the powertrain module is favored as it adds an additional degree of freedom to achieve flexibility in optimizing the battery module and inverter independently. However, it is essential that the converter is rated for high peak power and can maintain high ...

Contributors
Mullangi Chenchu, Hemanth, Ayyanar, Raja, Qin, Jiangchao, et al.
Created Date
2018

The dissertation encompasses the transformer-less single phase PV inverters for both the string and microinverter applications. Two of the major challenge with such inverters include the presence of high-frequency common mode leakage current and double line frequency power decoupling with reliable capacitors without compromising converter power density. Two solutions are presented in this dissertation: half-bridge voltage swing (HBVS) and dynamic dc link (DDCL) inverters both of which completely eliminates the ground current through topological improvement. In addition, through active power decoupling technique, the capacitance requirement is reduced for both, thus achieving an all film-capacitor based solution with higher reliability. Also ...

Contributors
Roy, Jinia, Ayyanar, Raja, Karady, George, et al.
Created Date
2017

Two major challenges in the transformer-less, single-phase PV string inverters are common mode leakage currents and double-line-frequency power decoupling. In the proposed doubly-grounded inverter topology with innovative active-power-decoupling approach, both of these issues are simultaneously addressed. The topology allows the PV negative terminal to be directly connected to the neutral, thereby eliminating the common-mode ground-currents. The decoupling capacitance requirement is minimized by a dynamically-variable dc-link with large voltage swing, allowing an all-film-capacitor implementation. Furthermore, the use of wide-bandgap devices enables the converter operation at higher switching frequency, resulting in smaller magnetic components. The operating principles, design and optimization, and control ...

Contributors
Xia, Yinglai, Ayyanar, Raja, Karady, George, et al.
Created Date
2017

The growth of energy demands in recent years has been increasing faster than the expansion of transmission facility construction. This tendency cooperating with the continuous investing on the renewable energy resources drives the research, development, and construction of HVDC projects to create a more reliable, affordable, and environmentally friendly power grid. Constructing the hybrid AC-HVDC grid is a significant move in the development of the HVDC techniques; the form of dc system is evolving from the point-to-point stand-alone dc links to the embedded HVDC system and the multi-terminal HVDC (MTDC) system. The MTDC is a solution for the renewable energy ...

Contributors
Yu, Jicheng, Karady, George, Qin, Jiangchao, et al.
Created Date
2017

Alternate sources of energy such as wind, solar photovoltaic and fuel cells are coupled to the power grid with the help of solid state converters. Continued deregulation of the power sector coupled with favorable government incentives has resulted in the rapid growth of renewable energy sources connected to the distribution system at a voltage level of 34.5kV or below. Of late, many utilities are also investing in these alternate sources of energy with the point of interconnection with the power grid being at the transmission level. These converter interfaced generation along with their associated control have the ability to provide ...

Contributors
Ramasubramanian, Deepak, Vittal, Vijay, Undrill, John, et al.
Created Date
2017

The past decades have seen a significant shift in the expectations and requirements re-lated to power system analysis tools. Investigations into major power grid disturbances have suggested the need for more comprehensive assessment methods. Accordingly, sig-nificant research in recent years has focused on the development of better power system models and efficient techniques for analyzing power system operability. The work done in this report focusses on two such topics 1. Analysis of load model parameter uncertainty and sensitivity based pa-rameter estimation for power system studies 2. A systematic approach to n-1-1 analysis for power system security as-sessment To assess the ...

Contributors
Mitra, Parag, Vittal, Vijay, Heydt, Gerald T, et al.
Created Date
2016