Engineering Commons^™

Analysis And Control Of Vsc Based Hvdc System Under Single-Line-To-Ground Fault Conditions, Xiaojie Shi

Doctoral Dissertations

To take full advantage of multilevel modular converter (MMC) and extend its application in high voltage direct current (HVDC) transmission systems, the ability to deal with severe unbalanced conditions, especially under single-line-to-ground (SLG) fault, is a key requirement.

This dissertation deals with the development of a fault handling strategy, which helps HVDC systems achieve continuous energy supply and desired operation performance under temporary SLG fault conditions while ensuring a smooth and fast black start for MMC-HVDC particularly if the system has to shut down when a permanent SLG fault occurs. Several related research topics will be discussed in this dissertation. …

Wide-Area Synchrophasor Measurement Applications And Power System Dynamic Modeling, Yin Lei

Doctoral Dissertations

The use of synchrophasor measurements system-wide has been providing significant assistance for grid dynamic monitoring, situation awareness and reliability improvement. Frequency Monitoring Network (FNET), as an academia-run synchrophasor measurement system, utilizes a large number of Internet-connected low-cost Frequency Disturbance Recorders (FDRs) installed at the distribution level to measure power system dynamics and provide both online and off-line applications, such as event detection, oscillation modes estimation, event replay, etc. This work aims to further explore applications of the FNET measurements and utilize measurement-based method in dynamic modeling.

Measurement-based dynamic reduction is an important application of synchrophasor measurement, especially considering the fact …

Dividing And Conquering Meshes Within The Nist Fire Dynamics Simulator (Fds) On Multicore Computing Systems, Donald Charles Collins

Masters Theses

The National Institute for Standards and Technology (NIST) Fire Dynamics Simulator (FDS) provides a computational fluid dynamics model of a fire, which can be visualized by using NIST Smokeview (SMV). Users must create a configuration file (*.fds) that describes the environment and other characteristics of the fire scene so that the FDS software can produce the output file (*.smv) needed for visualization.The processing can be computationally intensive, often taking between several minutes and several hours to complete. In many cases, a user will create a file that is not optimized for a multicore computing system. By dividing meshes within the …

Implementation Of A Neuromorphic Development Platform With Danna, Jason Yen-Shen Chan

Masters Theses

Neuromorphic computing is the use of artificial neural networks to solve complex problems. The specialized computing field has been growing in interest during the past few years. Specialized hardware that function as neural networks can be utilized to solve specific problems unsuited for traditional computing architectures such as pattern classification and image recognition. However, these hardware platforms have neural network structures that are static, being limited to only perform a specific application, and cannot be used for other tasks. In this paper, the feasibility of a development platform utilizing a dynamic artificial neural network for researchers is discussed.

Versatile Three-Phase Power Electronics Converter Based Real-Time Load Emulators, Jing Wang

Doctoral Dissertations

This dissertation includes the methodology, implementation, validation, as well as real-time modeling of a load emulator for a reconfigurable grid emulation platform of hardware test-bed (HTB). This test-bed was proposed by Center of Ultra-wide-area Resilient Electric Energy Transmission Network (CURENT) at the University of Tennessee, at Knoxville in 2011, to address the transmission level system challenges posed by contemporary fast changing energy technologies.

Detailed HTB introduction, including design concept, fundamental units and hardware construction, is elaborated. In the development, current controlled three-phase power electronics converter based emulator unit is adopted to create desired power system loading conditions.

In the application, …

A Low-Power Bfsk/Ook Transmitter For Wireless Sensors, Mohammed Shahriar Jahan

Doctoral Dissertations

In recent years, significant improvements in semiconductor technology have allowed consistent development of wireless chipsets in terms of functionality and form factor. This has opened up a broad range of applications for implantable wireless sensors and telemetry devices in multiple categories, such as military, industrial, and medical uses. The nature of these applications often requires the wireless sensors to be low-weight and energy-efficient to achieve long battery life. Among the various functions of these sensors, the communication block, used to transmit the gathered data, is typically the most power-hungry block. In typical wireless sensor networks, transmission range is below 10 …

A Ghz-Range, High-Resolution Multi-Modulus Prescaler For Extreme Environment Applications, Benjamin Matthew Mccue

Doctoral Dissertations

The generation of a precise, low-noise, reliable clock source is critical to developing mixed-signal and digital electronic systems. The applications of such a clock source are greatly expanded if the clock source can be configured to output different clock frequencies. The phase-locked loop (PLL) is a well-documented architecture for realizing this configurable clock source. Principle to the configurability of a PLL is a multi-modulus divider. The resolution of this divider (or prescaler) dictates the resolution of the configurable PLL output frequency. In integrated PLL designs, such a multi-modulus prescaler is usually sourced from a GHz-range voltage-controlled oscillator. Therefore, a fully-integrated …

A Magnetic Actuated Fully Insertable Robotic Camera System For Single Incision Laparoscopic Surgery, Xiaolong Liu

Doctoral Dissertations

Minimally Invasive Surgery (MIS) is a common surgical procedure which makes tiny incisions in the patients anatomy, inserting surgical instruments and using laparoscopic cameras to guide the procedure. Compared with traditional open surgery, MIS allows surgeons to perform complex surgeries with reduced trauma to the muscles and soft tissues, less intraoperative hemorrhaging and postoperative pain, and faster recovery time. Surgeons rely heavily on laparoscopic cameras for hand-eye coordination and control during a procedure. However, the use of a standard laparoscopic camera, achieved by pushing long sticks into a dedicated small opening, involves multiple incisions for the surgical instruments. Recently, single …

Isolated Wired And Wireless Battery Charger With Integrated Boost Converter For Phev And Ev Applications, Madhu Sudhan Chinthavali

Doctoral Dissertations

Vehicle charging and vehicle traction drive components can be integrated for multi-functional operations, as these functions are currently operating independently. While the vehicle is parked, the hardware that is available from the traction drive can be used for charging. The only exception to this would be the dynamic vehicle-charging concept on roadways. WPT can be viewed as a revolutionary step in PEV charging because it fits the paradigm of vehicle to infrastructure (V2I) wirelessly. WPT charging is convenient and flexible not only because it has no cables and connectors that are necessary, but due more to the fact that charging …

A Low-Power, Laser-Based Delta-Sigma Modulator For The Measurement Of Atmospheric Gas Composition, Christopher Edward Crowder

Masters Theses

With the increased attention on monitoring the atmosphere’s gas composition, new ways of accurately measuring these concentrations are needed. Along with the needed increase in measurement accuracy; size, space, and power reduction is also essential in modern systems. As semiconductor technology has advanced, the abilities to meet the previously mentioned criteria are becoming more realizable.

Instrumentation used to measure the atmosphere’s composition is traditionally large, taking up much needed space and using larger amounts of power. While the larger instrumentation provides the necessary accuracy, the other constraints are sacrificed. For this reason, a smaller, yet highly accurate solution is needed. …

Cmos Current-Frequency Signal Processing Unit For Bioimplantable Sensors, Madeline Nicole Threatt

Masters Theses

Over the past few decades, implantable monitoring of glucose, lactate acid, and pH monitoring has become a viable replacement for stationary monitoring. Implantable biosensing requires biosensors in conjunction with corresponding potentiostats and a signal processing unit to translate the data information to a more versatile, transmittable form. This thesis presents a current-mode signal processing unit (SPU) that merges the simplicity of a charging capacitor in feedback topology with the accuracy of a delta-sigma modulator to create a pulse train with a frequency proportional to the input current. The SPU was realized in a 0.18 µ[micro]m bulk CMOS process.

Radiation-Hardened Data Acquisition System Based On A Mask-Programmable Analog Array, Jacob Hunter Shelton

Masters Theses

Data acquisition systems capable of extreme temperature and radiation environments are of dire need in an era of great nuclear energy generation. Efforts to respond to recent nuclear accidents, such as those caused by natural disasters at Fukushima, have suffered in promptness and effectiveness due to the lack of information gathered from these sites. Currently, there are no systems available that accurately acquire, digitize, and remotely report this data in the presence of harsh radiation.

Using a mask-programmable analog array prototype chip designed for Triad Semiconductor and an FMI frequency synthesizer, both verified to beyond 300 kRad and 125ºC and …

Ultra-Low-Power Configurable Analog Signal Processor For Wireless Sensors, James Kelly Griffin

Masters Theses

The demand for on-chip low-power Complementary Metal Oxide Semiconductor (CMOS) analog signal processing has significantly increased in recent years. Digital signal processors continue to shrink in size as transistors half in size every two years. However, digital signal processors (DSP's) notoriously use more power than analog signal processors (APS's). This thesis presents a configurable analog signal processor (CASP) used for wireless sensors. This CASP contains a multitude of processing blocks include the following: low pass filter (LPF), high pass filter (HPF) integrator, differentiator, operational transconductance amplifier (OTA), rectifier with absolute value functionality, and multiplier. Each block uses current-mode processing and …