Vehicular communication network consists of different wireless communication technologies working in conjunction with each other. These different wireless communication technologies have different technical parameters. Wireless communication technology includes Dedicated Short-Range Communication, WiFi, WiMAX etc. depending upon their network range, data bit transfer rate, safe effective maximum intended communication range, modulation technique adopted and many more, are deployed for specific safety application. The main objective of Intelligent Transport System (ITS) is Safety. Under safety application there are many objectives including safe approach to the intersection, pre and post-crash warning, total loss control correction etc. these safety applications require specific parameter of communication technology i.e. for safe intersection approach data bit rate need not to be high and other safety application seeks different parameter. It is obvious that no single wireless communication technology could fulfill all the specifics of communication technology and objective of ITS. In this research important wireless communication discussed. Their pros and cons are summarized in the vehicular environment. In order to show the importance of wireless communication technology in Vehicular network, one among many safety applications is simulated. In the simulation, safe approach to unsignalized intersection is simulated. Simulation is performed on VISSIM software developed by PTV group, Germany. Simulation is based on Nakagami Wireless probabilistic model under relaxed radio condition (no interferences) and finally conclusion is made. / A Thesis submitted to the Department of Electrical and Computer Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Fall Semester 2018. / November 5, 2018. / Includes bibliographical references. / Bruce Harvey, Professor Directing Thesis; Simon Foo, Committee Member; Shonda Bernadin, Committee Member.

The modern day smart grid technology relies heavily on data acquisition and analysis. A distributed controller governs smart microgrid functions with one or more renewable sources and smart controllable loads. This sort of intelligent, scalable system is the primary drive for the Energy Internet (EI). Hence, in modern-day power systems engineering to analyze, understand and make efficient system design choices that capture robustness and scalability, Hardware in the Loop (HIL) simulations are required. Real-Time Simulations (RTS) is the state of the art technology thrusting the capstone of innovation for this industry. As engineers, we can model, simulate and validate smart grids operations more rapidly, robustly and reliably using RTS. With enough smaller time step for the simulation, the boundary between the real and the simulated systems slowly vanishes. It also enables the system to be simulated as Controller Hardware in the Loop (CHIL) or Power Hardware in the Loop (PHIL) setups, evolving and imitating the real physical world. The HIL (Hardware in the Loop) setup also enables a real data source or sink to be in the system to form the loop of exchange between the simulated system and real-world hardware which is most often a control hardware. The implementation of such a setup is made possible at Center for Advanced Power Systems (CAPS), named as Hardware in the Loop Test-Bed (HIL-TB). This evaluation architecture provides a systematic solution to HIL simulations. Now the sampling time for real-world sensors is generally in the order of microseconds, enabling this collected data to emulate the cyber-physical domain accurately. Thus, the challenge previously was to address the throughput of real-world input data into the simulated system efficiently and correctly. The quality of the Design of Simulation (DoS) using the real world data in the form of Real Time Input Profile (RTIP), improves, affects the quality of response of the real-time cyber-physical system simulation. Thus great care needs to be taken to prepare, prune and project the RTIPs to improve and enhance the system performance evaluation index. To solve this problem, partially successful attempts have been made in the direction of machine learning by using methods like clustering and regression to characterize large input profiles or by breaking them into subsections using fixed length sliding window techniques. These classic methods then perform data analysis on those sub-pieces to distinguish among a variety of input profiles and assign an index. These sub-profiles or sections would be then loaded into the simulation as environmental input to represent the physical system in the HIL simulations. This traditional procedure is observed to be arbitrary because clustering algorithms and metrics for methods like regression or classification are user-defined and there exists no standard practice to deal with huge input profiles. There have also been confusions regarding the size of the sliding window to create subsections, subsection joining logic, etc. Thus, to address this issue, the primary focus of this study is to present a systematic, controlled, reliable procedure to explore, screen, crop large input profiles and then to compress the same by selecting sections with most relative importance using a modified version of “knapsack” dynamic programming algorithm. This compression primarily aims to shrink down the total simulation time without much loss of information. The latter part of this study focuses towards response driven performance evaluation of the HIL simulations. This is ensured by targeted compression of original input profile based on the certain requirement of the simulation. This approach ensures that the control algorithm (CHIL simulations) or any other system operator is driven in a specific direction in the simulation response space by effectively sampling the input parameters space. The fully automated HIL-TB evaluation framework aided with Input Profile Time Compression (IPTC) module delivers a fast-convergent validation for the performance evaluation with relatively similar system response. In this study, the IPTC module has been applied to seven load profiles to compress their temporal length by a third. The case study used for the simulation with these RTIPs is the Future Renewable Electric Energy Delivery and Management (FREEDM) IEEE seven node system. The test results show great coherence between the uncompressed and compressed response and validate the performance of the IPTC module applied to real-world HIL simulations. Thus, it can conclude that the functionality of the IPTC module is validated by the quality of simulation response gained out of the compressed simulation as compared to uncompressed simulation. In future, endeavors can be made in this path by expanding the functionality of this compression module to not only identifying and managing important sections based on some initial assumption about the objective of the control application but also providing cognitive, autonomous understanding of the behavior of the controls and using that knowledge accomplishing compression of large input profiles. / A Thesis submitted to the Department of Electrical and Computer Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Fall Semester 2017. / November 15, 2017. / Design of Simulation, Hardware in the Loop Simulation, Input Profile Compression, Real Time Simulation, Time Compression / Includes bibliographical references. / Omar Faruque, Professor Co-Directing Thesis; Mischa Steurer, Professor Co-Directing Thesis; Hui Li, Committee Member.

Digital Signal Processing (DSP) performs a very important role in various applications of electrical engineering like communications and signal enhancement. In many situations one finds that the DSP hardware available are fixed point processors. In these situations, it is necessary to perform DSP with high accuracy using the least amount of hardware resources. This thesis looks into an approach to calculate the two dimensional Discrete Hirschman Transform (DHT), the inverse DHT, the Hirschman Cosine Transform (HCT) and the inverse HCT using fixed-point hardware. The complex coefficients required for the transform are calculated beforehand and saved as vectors. Special attention has been given to minimize errors due to scaling. The processed image and the original image does not show significant difference even for DFT or DCT length of 128. Mean square errors of -37 dB for the DHT and -40 dB for the HCT could be obtained for DFT and DCT lengths of 128. / A Thesis submitted to the Department of Electrical and Computer Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Fall Semester 2017. / November 17, 2017. / DCT, DFT, DHT, HCT, HOT / Includes bibliographical references. / Victor E. DeBrunner, Professor Directing Thesis; Linda DeBrunner, Committee Member; Bruce A. Harvey, Committee Member.

Power electronics technology has been widely used in electric power system to achieve high energy efficiency and high renewable energy penetration. Small signal instability phenomena could easily occur in systems with abundant power electronics because of high order passive elements and controller interactions among power converters. These instability issues degrade power quality or even cause system failure. Therefore it is necessary to build accurate small signal models for stability analysis and develop effective resonance mitigation techniques for stability improvement. The general stability analysis methods including eigenvalues-based method, component connection method, passivity-based method and impedance-based method have been evaluated and summarized. The impedance-based method is selected as the stability analysis tool for this research due to its advantages compared to other methods. Besides, three popular resonance suppression techniques, i.e. passive damper, active damper and virtual impedance control, are also studied and evaluated. The virtual impedance control is of interest because it does not reduce system efficiency or reliability compared to both the passive and active damper. A unified impedance-based stability criterion (UIBSC) has been proposed for paralleled grid-tied inverters. Compared to the traditional IBSC which evaluates all minor loop gains (MLGs) of individual inverter, the UIBSC assesses the derived global minor loop gain (GMLG) only once to determine system stability. As a result, the computation efforts can be significantly reduced when system contains a large number of inverters. In addition, a stability-oriented design guideline has been derived for the paralleled grid-tied inverters based on the GMLG. By using the guideline, the grid impedance, inverter filter parameters, time delays of digital control and control parameters can be analyzed or designed to meet the system stability requirement. The small signal stability of the FREEDM system is a critical issue due to the abundant power electronics devices and flexible control strategies. The impedance modeling methods for current controlled inverters, inverter stage of the SST, DAB converters are developed. The influences of control schemes on power converter terminal behaviors are analyzed as well. Stability criteria for several types of grid enabled by the SST are derived. The bidirectional power flow effect is also considered. These instability phenomena are demonstrated in ac, dc, and hybrid ac/dc grids of FREEDM system using HIL test bed. Finally, the conclusions are given and the scope of future work is discussed. / A Dissertation submitted to the Department of Electrical and Computer Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester 2017. / September 7, 2017. / FREEDM system, harmonics, instability mitigation, paralleled inverters, power converter interraction, stability criterion / Includes bibliographical references. / Hui Li, Professor Directing Dissertation; Emmanuel G. Collins, University Representative; Mischa Steurer, Committee Member; Ming Yu, Committee Member.

High Temperature Superconductors (HTS) have the advantage of carrying direct current at zero resistance when operated below their critical temperature. At lower temperatures, these superconductors have the capability of carrying higher current densities. HTS power systems have applications in electrical power grids, defense, naval, aircraft, and industrial sectors. HTS devices enable higher efficiency while providing resiliency and reliability to power systems. This study developed models for superconducting cable system with two terminations, HTS cable, and cryo-cooler. The models combined electrical and cryogenic thermal aspects of the superconducting cable system. Several operating scenarios were simulated. Some contingencies such as cryo-cooler failure, circulation system failure were also modeled. A comparison of AC and DC cables was also analyzed in the system. The simulation models help in the analysis of the effects of system failure and to estimate the time required to turn off the system before the cable is affected. The results indicate that most of the heat load into the system is due to the terminations which are the interfaces between the superconducting cable and the room temperature components. In the contingency situations such as cryo-cooler failure, the time required to turn-off the system is several minutes. These results help us protect the cable from catastrophic damage during unexpected situations. Through these models, it is possible to calculate the maximum current that can be run through the system before the cable reaches a potential quench. / A Thesis submitted to the Department of Electrical and Computer Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Fall Semester 2017. / November 14, 2017. / Includes bibliographical references. / Sastry V. Pamidi, Professor Directing Thesis; Simon Foo, Committee Member; Pedro Moss, Committee Member.

The Heisenberg Uncertainty principle is a fundamental concept from Quantum Mechanics that also describes the Fourier Transform. Unfortunately, it does not directly apply to the digital signals. However, it can be generalized if we use entropy rather than energy to form an uncertainty relation. This form of uncertainty, called the Hirschman Uncertainty, uses the Shannon Entropy. The Hirschman Uncertainty is defined as the average of the Shannon entropies of the discrete-time signal and its Fourier Transform. The functions that minimize this uncertainty are not the wellknown Gaussians from the Heisenberg theory, but are the picket fence functions first noticed in wavelet denoising. This connection suggests that the Hirschman Uncertainty is fundamental, but not conclusively. Here in this research, we develop two new uncertainty measures that are derived from the Hirschman Uncertainty. We want to use these measures to explore the fundamental nature of the Hirschman Uncertainty. In the first case, we replace the Shannon entropy with the Rényi entropy and study the impact of varying the Rényi order on the uncertainty of various digital signals. We call this new uncertainty measure, the Hirschman-Rényi uncertainty denoted by U[alpha over ½](x). We find that the derived uncertainty measure is invariant to the Rényi order in case of the picket fence signals and varies in case of other the digital signals like rectagular, cosine, square wave signals to name a few. This new uncertainty measure that utilizes the Rényi entropy decays with the increase in Rényi order value. Considering the invariance in uncertainty in case of picket fence signal, we can use either Shannon or Rényi entropy with any value of Rényi order to calculate Hirschman Uncertainty. In the second case, we derive an uncertainty measure that replaces the Fourier Transform with the Fractional Fourier Transform. The Hirschman Uncertainty using dFRT denoted by U[alpha over ½](x) is explored with the help of the minimizers of the Hirschman Uncertainty (the picket fence signals) along with the other digital signals. In this case, we find that the degree of rotation in the Fractional Fourier Transform does impact the uncertainty at the integer values of the transfer order. But for the non-interger values of the transfer order, the uncertainty variations are greatly reduced or are minimal. Finally to help verify our theory, we perform a classical texture recognition experiment. We find that the recognition performance follows directly as our developed Hirschman Rényi Uncertainty and the Hirschman Uncertainty using dFRT theory suggests. Additionally, it appears that a predictive solution for the proper selection of the Rényi order and the rotation angle can be developed that could significantly aid in image analysis. Our recognition results are consistent with entropic invariance theory in case of the two uncertainty measures. These results suggests that the Hirschman Uncertainty may be a fundamental characteristic of the digital signals. / A Dissertation submitted to the Department of Electrical and Computer Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester 2015. / November 3, 2015. / Discrete fractional fourier transform, entropy, Hirschman Uncertainty, Texture classification, Uncertainty / Includes bibliographical references. / Victor DeBrunner, Professor Directing Dissertation; Anuj Srivastava, University Representative; Linda DeBrunner, Committee Member; Bruce Harvey, Committee Member; Rodney Roberts, Committee Member.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering, 1953. / Includes bibliographical references. / by Rudolph John Cypser. / Sc.D.

Recent years have seen a push to provide a fast, sensitive, and quantitative diagnostic tool for biomedical applications. A search for new methods that can perform label-free and bond-specific determination of tissue and disease types with high spatial resolution is much desired. To address these needs, we have developed a mid-infrared photothermal system for sensitive and non-destructive characterization of samples. Our system utilizes a mid-infrared pump with a near-infrared probe for label-free spectroscopy and high spatial resolution imaging. In particular, this research focuses on optimization of the photothermal system, exploration of novel nonlinear photothermal phenomena, and development of a sub-diffraction limited mid-infrared imaging system. Photothermal spectroscopy is a pump-probe technique that utilizes a thermal lens effect in the sample for contrast. With the use of a high brightness mid-infrared pump laser, we extend photothermal spectroscopy into the mid-infrared regime for sensitive detection with high signal contrast. Targeting vibrational modes intrinsic to the sample allows for label-free characterization. Use of a fiber laser probe provides improved spatial resolution and takes advantage of the well-developed detector technology at near-infrared wavelengths. The research presented will be divided into three parts: optimization of the photothermal system, investigation of novel nonlinear photothermal phenomena, and photothermal spectroscopy and imaging for biomedical applications. Optimization of fiber laser design and experimental setup results in >100x increase in signal strength and over an order of magnitude improvement in signal contrast. With an optimized system, linear and nonlinear mid-infrared photothermal spectroscopy of a liquid crystal sample is demonstrated. For the first time, multiple bifurcations are reported in the nonlinear regime, shedding insight on the photothermal laser-matter interaction across phase transitions of a liquid crystal sample. Using a raster-scanning approach, sub-diffraction limited mid-infrared imaging is demonstrated. With this technique, various tissue types within the brain can be distinguished from one another, including differentiation between healthy and tumor tissue. Hyperspectral imaging of biological tissues demonstrates the potential of this technique to combine both spectral and spatial information for sample characterization. We present a photothermal system with the potential to meet the demands in drug and food safety, environmental monitoring, biomedicine, and security. / 2018-11-02T00:00:00Z

<p> A method for sizing battery energy storage (BES) systems for use in mitigating voltage flicker caused by solar intermittency in photovoltaic generation was developed. The method creates a &ldquo;design day&rdquo; from existing solar data and designs the power and energy requirements for a BES system that can help a photovoltaic facility mitigate flicker caused by solar activity associated with the design day. An economic analysis of lead-acid and lithium-ion options for the BES was also developed. The method was then applied to a proposed photovoltaic project in the Midwestern United States.</p><p>

A satellite's absolute attitude and angular rate are both important measurements for satellite missions that require navigation. Typically, these measurements have been made by separate sensors, with star cameras being used to determine a satellite's absolute attitude, and gyroscopes being used as the primary rate sensors. Recently, there have been multiple efforts to measure both of these quantities using only the star camera, however the work primarily involves solutions where the optical sensor and the unit that processes the images are separate integrated circuits. Operation in this modality requires the use of chip to chip communication in order to estimate angular rate from star tracker images, which can lead to an increase in system power, a degradation in performance, and increased latency. The goal of this thesis is to consolidate the sensing and processing into a single integrated circuit. The design and evaluation of a digital processing unit that estimates angular rate and facilitates the realization of image sensor and processor integration is presented. The processing unit is implemented in UMC's 130 nm process, has an area of 10 mm × 200 μm, and consumes 8.253 mW of power.