Engineering Commons^™

Design And Implementation Of An Isfet Sensor With Integration Of An On-Chip Processor, Shaghayegh Aslanzadeh

Doctoral Dissertations

Portable sensors are used in many applications. Among them, pH sensors are suitable for quantifying and identifying various analytes in real-time and doing so non-invasively. The analytes may have environmental impact such as in water quality monitoring. The analytes may also have biological impact such as monitoring cell culture or remote patient health assessment. CMOS based sensors are compact and enable low power consumption suitable for these portable applications.

This work reports on the development of a portable CMOS based pH sensor. The contributions of this dissertation are as follows. First, a differential pH sensor, with two different sized electrodes …

State Estimation For Vsc-Mtdc Power Systems Considering Droop Control And Operating Limits, Wei Feng

Doctoral Dissertations

Power systems with voltage source converter-based multi-terminal DC (VSC-MTDC) have received great interest in both the academic and industrial worlds in recent years. The introduction of VSC-MTDC systems into the power system industry brings not only significant benefits but also severe challenges due to the complex structures, different operating behaviors, and dynamic features of VSC-MTDC. State estimation (SE), an important function in the Energy Management System (EMS) for real-time monitoring, has become a challenging issue for VSC-MTDC systems. The traditional approach to dealing with this problem only considers the quasi-steady status of a VSC and ignores its dynamic features. Therefore, …

Arc Flash In Single-Phase Electrical Systems, John Francis Wade

Doctoral Dissertations

Arc flash and blast are hazards unique to electrical installations. Such events can start fires, destroy equipment, and severely injure or kill workers. NFPA 70E and IEEE 1584 are defining standards for arc flash hazard analysis used during system design, construction, and maintenance. Both focus on three-phase faults for calculations since three-phase power distribution is predominant in utility and industrial applications. However, discussion of arc flash in single-phase systems prevalent in residential and commercial facilities is excluded. Single-phase faults can also occur in a variety of industrial and utility circumstances.

This dissertation explores historic background and treatment of arc flash …

Synchronized Measurement Data Conditioning And Real-Time Applications, Xianda Deng

Doctoral Dissertations

Phasor measurement units (PMU), measuring voltage and current phasor with synchronized timestamps, is the fundamental component in wide-area monitoring systems (WAMS) and reveals complex dynamic behaviors of large power systems. The synchronized measurements collected from power grid may degrade due to many factors and impacts of the distorted synchronized measurement data are significant to WAMS. This dissertation focus on developing and improving applications with distorted synchronized measurements from power grid. The contributions of this dissertation are summarized below. In Chapter 2, synchronized frequency measurements of 13 power grids over the world, including both mainland and island systems, are retrieved from …

Stability Analysis And Control Of Nonlinear Power System Oscillations, Xin Xu

Doctoral Dissertations

This work investigates the nonlinear oscillatory behaviors of multi-machine power systems. New model-based and measurement-based approaches are proposed for stability analysis and control of nonlinear oscillations.

For stability analysis, a recently proposed model-based nonlinear oscillation analysis method, nonlinear modal decoupling (NMD), is investigated on its ability in capturing the stability information of a multi-machine power system. From the differential-equation model of the power system, the NMD inversely constructs a set of 1-degree-of-freedom nonlinear oscillators, referred to as decoupled oscillators or subsystems, with each one corresponding to an oscillation mode of the original system. It is shown that retaining high order …

Development Of A Robust Wideband Gnss Rf Frontend With Resilient Interference Blocking, Farshid Tamjid

Doctoral Dissertations

Recently, there has been an increasing demand for GNSS systems’ use for numerous applications such as public security, disaster relief, weather forecast, transportation, hydrologic monitoring, aviation, navigation positions and so on. Such systems must have a wideband performance (1.16 GHz to 1.61 GHz), high quality reception (which requires antenna with low AR, high RHCP gain, high F/B ratio, and high RL), portable size, and low cost. Our efforts here are geared towards the receiving side of such communication. The antennas are the first stage of the long receiver chain. Development of such wideband high quality antennas is challenging as most …

Approaches To Studying Bacterial Biofilms In The Bioeconomy With Nanofabrication Techniques And Engineered Platforms., Michelle Caroline Halsted

Doctoral Dissertations

Studies that estimate more than 90% of bacteria subsist in a biofilm state to survive environmental stressors. These biofilms persist on man-made and natural surfaces, and examples of the rich biofilm diversity extends from the roots of bioenergy crops to electroactive biofilms in bioelectrochemical reactors. Efforts to optimize microbial systems in the bioeconomy will benefit from an improved fundamental understanding of bacterial biofilms. An understanding of these microbial systems shows promise to increase crop yields with precision agriculture (e.g. biosynthetic fertilizer, microbial pesticides, and soil remediation) and increase commodity production yields in bioreactors. Yet conventional laboratory methods investigate these micron-scale …

Design And Implementation Of A Multi-Modal Sensor With On-Chip Security, Ava Hedayatipour

Doctoral Dissertations

With the advancement of technology, wearable devices for fitness tracking, patient monitoring, diagnosis, and disease prevention are finding ways to be woven into modern world reality. CMOS sensors are known to be compact, with low power consumption, making them an inseparable part of wireless medical applications and Internet of Things (IoT). Digital/semi-digital output, by the translation of transmitting data into the frequency domain, takes advantages of both the analog and digital world. However, one of the most critical measures of communication, security, is ignored and not considered for fabrication of an integrated chip. With the advancement of Moore's law and …

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 …

Leveraging Conventional Internet Routing Protocol Behavior To Defeat Ddos And Adverse Networking Conditions, Jared M. Smith

Doctoral Dissertations

The Internet is a cornerstone of modern society. Yet increasingly devastating attacks against the Internet threaten to undermine the Internet's success at connecting the unconnected. Of all the adversarial campaigns waged against the Internet and the organizations that rely on it, distributed denial of service, or DDoS, tops the list of the most volatile attacks. In recent years, DDoS attacks have been responsible for large swaths of the Internet blacking out, while other attacks have completely overwhelmed key Internet services and websites. Core to the Internet's functionality is the way in which traffic on the Internet gets from one destination …