Matching Items (71)
Filtering by
- All Subjects: Political Science
- All Subjects: history
- All Subjects: engineering
- Creators: School of Politics and Global Studies
- Creators: Ayyanar, Raja
Description
The high penetration of photovoltaic (PV) both at the utility and at the distribu-tion levels, has raised concerns about the reliability of grid-tied inverters of PV power systems. Inverters are generally considered as the weak link in PV power systems. The lack of a dedicated qualification/reliability standard for PV inverters is a main barrier in realizing higher level of confidence in reliability. Development of a well-accepted design qualification standard specifically for PV inverters will help pave the way for significant improvement in reliability and performance of inverters across the entire industry. The existing standards for PV inverters such as UL 1741 and IEC 62109-1 primarily focus on safety. IEC 62093 discusses inverter qualification but it includes all the balance of sys-tem components and therefore not specific to PV inverters. There are other general stan-dards for distributed generators including the IEEE1547 series of standards which cover major concerns like utility integration but they are not dedicated to PV inverters and are not written from a design qualification point of view. In this thesis, some of the potential requirements for a design qualification standard for PV inverters are addressed. The IEC 62093 is considered as a guideline and the possible inclusions in the framework for a dedicated design qualification standard of PV inverter are discussed. The missing links in existing PV inverter related standards are identified by performing gap analysis. Dif-ferent requirements of small residential inverters compared to large utility-scale systems, and the emerging requirements on grid support features are also considered. Electric stress test is found to be the key missing link and one of the electric stress tests, the surge withstand test is studied in detail. The use of the existing standards for surge withstand test of residential scale PV inverters is investigated and a method to suitably adopt these standards is proposed. The proposed method is studied analytically and verified using simulation. A design criterion for choosing the switch ratings of the inverter that can per-form reliably under the surge environment is derived.
ContributorsAlampoondi Venkataramanan, Sai Balasubramanian (Author) / Ayyanar, Raja (Thesis advisor) / Vittal, Vijay (Committee member) / Heydt, Gerald (Committee member) / Arizona State University (Publisher)
Created2011
Description
In modern electric power systems, energy management systems (EMSs) are responsi-ble for monitoring and controlling the generation system and transmission networks. State estimation (SE) is a critical `must run successful' component within the EMS software. This is dictated by the high reliability requirements and need to represent the closest real time model for market operations and other critical analysis functions in the EMS. Tradi-tionally, SE is run with data obtained only from supervisory control and data acquisition (SCADA) devices and systems. However, more emphasis on improving the performance of SE drives the inclusion of phasor measurement units (PMUs) into SE input data. PMU measurements are claimed to be more accurate than conventional measurements and PMUs `time stamp' measurements accurately. These widely distributed devices meas-ure the voltage phasors directly. That is, phase information for measured voltages and currents are available. PMUs provide data time stamps to synchronize measurements. Con-sidering the relatively small number of PMUs installed in contemporary power systems in North America, performing SE with only phasor measurements is not feasible. Thus a hy-brid SE, including both SCADA and PMU measurements, is the reality for contemporary power system SE. The hybrid approach is the focus of a number of research papers. There are many practical challenges in incorporating PMUs into SE input data. The higher reporting rates of PMUs as compared with SCADA measurements is one of the salient problems. The disparity of reporting rates raises a question whether buffering the phasor measurements helps to give better estimates of the states. The research presented in this thesis addresses the design of data buffers for PMU data as used in SE applications in electric power systems. The system theoretic analysis is illustrated using an operating electric power system in the southwest part of the USA. Var-ious instances of state estimation data have been used for analysis purposes. The details of the research, results obtained and conclusions drawn are presented in this document.
ContributorsMurugesan, Veerakumar (Author) / Vittal, Vijay (Committee member) / Heydt, Gerald (Committee member) / Ayyanar, Raja (Committee member) / Arizona State University (Publisher)
Created2013
Description
Solar power generation is the most promising technology to transfer energy consumption reliance from fossil fuel to renewable sources. Concentrated solar power generation is a method to concentrate the sunlight from a bigger area to a smaller area. The collected sunlight is converted more efficiently through two types of technologies: concentrated solar photovoltaics (CSPV) and concentrated solar thermal power (CSTP) generation. In this thesis, these two technologies were evaluated in terms of system construction, performance characteristics, design considerations, cost benefit analysis and their field experience. The two concentrated solar power generation systems were implemented with similar solar concentrators and solar tracking systems but with different energy collecting and conversion components: the CSPV system uses high efficiency multi-junction solar cell modules, while the CSTP system uses a boiler -turbine-generator setup. The performances are calibrated via the experiments and evaluation analysis.
ContributorsJin, Zhilei (Author) / Hui, Yu (Thesis advisor) / Ayyanar, Raja (Committee member) / Rodriguez, Armando (Committee member) / Arizona State University (Publisher)
Created2013
Description
The Smart Grid initiative describes the collaborative effort to modernize the U.S. electric power infrastructure. Modernization efforts incorporate digital data and information technology to effectuate control, enhance reliability, encourage small customer sited distributed generation (DG), and better utilize assets. The Smart Grid environment is envisioned to include distributed generation, flexible and controllable loads, bidirectional communications using smart meters and other technologies. Sensory technology may be utilized as a tool that enhances operation including operation of the distribution system. Addressing this point, a distribution system state estimation algorithm is developed in this thesis. The state estimation algorithm developed here utilizes distribution system modeling techniques to calculate a vector of state variables for a given set of measurements. Measurements include active and reactive power flows, voltage and current magnitudes, phasor voltages with magnitude and angle information. The state estimator is envisioned as a tool embedded in distribution substation computers as part of distribution management systems (DMS); the estimator acts as a supervisory layer for a number of applications including automation (DA), energy management, control and switching. The distribution system state estimator is developed in full three-phase detail, and the effect of mutual coupling and single-phase laterals and loads on the solution is calculated. The network model comprises a full three-phase admittance matrix and a subset of equations that relates measurements to system states. Network equations and variables are represented in rectangular form. Thus a linear calculation procedure may be employed. When initialized to the vector of measured quantities and approximated non-metered load values, the calculation procedure is non-iterative. This dissertation presents background information used to develop the state estimation algorithm, considerations for distribution system modeling, and the formulation of the state estimator. Estimator performance for various power system test beds is investigated. Sample applications of the estimator to Smart Grid systems are presented. Applications include monitoring, enabling demand response (DR), voltage unbalance mitigation, and enhancing voltage control. Illustrations of these applications are shown. Also, examples of enhanced reliability and restoration using a sensory based automation infrastructure are shown.
ContributorsHaughton, Daniel Andrew (Author) / Heydt, Gerald T (Thesis advisor) / Vittal, Vijay (Committee member) / Ayyanar, Raja (Committee member) / Hedman, Kory W (Committee member) / Arizona State University (Publisher)
Created2012
Description
The purpose of this thesis will be to compare and contrast films made by German and American directors about World War II and the Vietnam War, respectively. First, we will provide a list of the films including a brief summary and the reasons why that specific film was chosen for this analysis. Next, we will give background information about the two wars and the time period in the respective nations. The next steps are the actual project. First, we will list the criteria for analysis and why we chose those specific items to focus on. Lastly, we will provide an analysis of each film individually; going through the criteria previously provided. After reading the thesis the reader will be able to understand how filmmaking can show the feelings and sentiments of a nation during a specific time period, like war.
ContributorsRen, Haimo (Co-author) / Ahern, Jared (Co-author) / Bradley, Christopher (Thesis director) / Forss, Brennan (Committee member) / Barrett, The Honors College (Contributor) / School of Accountancy (Contributor) / Department of Supply Chain Management (Contributor) / W. P. Carey School of Business (Contributor) / School of Politics and Global Studies (Contributor)
Created2015-05
Description
The purpose of this research is to identify the factors contributing the resiliency of Syria's President Assad amongst a backdrop of falling authoritarians during the Arab Spring. After determining the Assad's regime's strategies of authoritarian rule both before and after the 2011 uprisings, this paper theorizes what Assad's persistence is most dependent on today by analyzing his discourse throughout the conflict. Assad's framing of the war to the media has significantly legitimized his rule.
ContributorsKassab, Seema (Author) / Parmentier, Mary Jane (Thesis director) / Simon, Sheldon (Committee member) / Barrett, The Honors College (Contributor) / Department of Economics (Contributor) / W. P. Carey School of Business (Contributor) / School of Politics and Global Studies (Contributor) / Sandra Day O'Connor College of Law (Contributor)
Created2015-05
Description
Since Dylan Roof, a white supremacist, shot and killed nine members of a black church in Charleston on June 17, 2015, Confederate symbols have stood at the center of much controversy across the United States. Although the Confederate battle flag remains the most obvious example, the debate took a particular form in Tennessee, centering on the image of General Nathan Bedford Forrest. Born in 1822 to a poor family, he left school early to work. Although his work in the slave trade made him a millionaire, his later participation in the massacre of over 300 black soldiers at Fort Pillow in 1864 during the Civil War and association with the Ku Klux Klan cemented his reputation as a violent racist. Yet, many white Tennesseans praised him as a hero and memorialized him. This thesis examines Nathan Bedford Forrest State Park in Benton County and Forrest Park, now Health Sciences Park, in Memphis to examine what characteristics denote a controversial memorial. Specifically, I focus on the physical form, the location, and the demographics of the area, investigating how these components work together to give rise to controversy or acceptance of the memorial's image. Physical representations greatly impact the ideas associated with the memorial while racial demographics affect whether or not Forrest's representation as a hero speaks true to modern interpretations and opinions.
ContributorsFish, Caroline Rose (Author) / Longley, Rodney (Thesis director) / Suk, Mina (Committee member) / School of Historical, Philosophical and Religious Studies (Contributor) / School of Politics and Global Studies (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
This research looks at the state of Anglo-American political relations since 1980. By examining the political partnerships between Ronald Reagan and Margaret Thatcher, Margaret Thatcher and George H.W. Bush, George W. Bush and Tony Blair, Barack Obama and Gordon Brown, and Barack Obama and David Cameron, it explores if the so called ‘special relationship’ remains so special today in a world of growing political animosity and challenges. The thesis argues that the success of the ‘special relationship’ between the United States and United Kingdom has not been just due to similar political ideologies or goals, but also personal friendships which often overcame national interests or immediate personal political gain. Furthermore, it is often the periods of disagreement between these sets of leaders that helped strengthen the relationship between America and Britain, evidenced by episodes like the Falklands War, policy towards the Soviet Union, the invasion of Grenada, and the wars in Iraq and Afghanistan. Ultimately, the thesis explores how current relations have deteriorated due to problems on both sides of the Atlantic under the Obama, Brown, and Cameron administrations, but the research concludes that the special relationship is, while damaged, alive and fixable.
ContributorsGavin, Stephen Christopher (Author) / Critchlow, Donald (Thesis director) / Stermetz, Catherine (Committee member) / School of Politics and Global Studies (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12
DescriptionChildren's book on life and career of Governor Jon Huntsman with civics lessons tied into story. Context paper explaining political science and communication theories as well as background on creative project.
ContributorsBenning, Annica (Co-author) / Huntsman, Elizabeth (Co-author) / Symons, Adam (Thesis director) / Martin, Judith (Committee member) / Trumble, Anna (Committee member) / Barrett, The Honors College (Contributor) / School of Politics and Global Studies (Contributor)
Created2014-05
Description
The Phoenix Coyotes entered bankruptcy and NHL stewardship in 2009 because of poor initial planning, short-sighted private ownership, and geographical constraints associated with the team's location in Glendale. The subsequent sale process extended from 2009-2013 and included multiple potential suitors, municipal politics, and international finance as the NHL fought to keep the troubled franchise in Phoenix.
ContributorsPorter, Brendan Francis (Author) / Simpson, Brooks (Thesis director) / Lynch, John (Committee member) / Barrett, The Honors College (Contributor) / School of Politics and Global Studies (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2014-12