Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

INE/AUTC 10.0

Current source Inverter for fuel cell Application

In recent years, the scientific renaissance has turned towards alternative energy. Scientific research and dissertations of all degrees, doctoral, Master, and even bachelor's degrees include. Green energy and alternative solution to protect the environment from increasing pollution. Different inverters have been used to increase the potential for power resulting from devices that do not have the efficiency to increase power. Multilevel inverter, voltage inverter, current sources inverter single phase and three phase which-efficiency DC-AC to connected with fuel cell. The inverter topology is present in the project to increase the voltage gain. The MATLAB Simulink results are presented with value for the parameter. The current source inverter single-phase H-bridge topology is used as the source of the explanation (Inverter topology)

Low-Noise, Low-Power Analog Front End for Dual Detector, Event-Driven Radioactive Isotope Identification

An analog front end (AFE) design for a low-noise, low-power, event-driven radioactive spectroscopy system is implemented in a 65 nm CMOS technology. The AFE is optimized for use with two scintillation based detectors, CsI(Na) and LaBr3(Ce), that utilize photo-multiplier tubes for charge amplification. The amplification within the AFE is accomplished through charge sensitive amplifier designs that are tailored to each detector type. The AFE includes adjustable bias generation circuits to allow amplifier tuning for process, voltage, and temperature variations. The presented AFE is implemented along with analog to digital acquisition circuits and a microcontroller to provide a single-chip radioactive spectroscopy system ASIC. The fabricated system ASIC performance is verified through radioactive spectroscopy testing of known isotope samples. Advisors: Sina Balkir and Michael Hoffma

On channel adaptive energy management in wireless sensor networks

Energy constraints in a wireless sensor network are crucial issues critically affecting the network lifetime and connectivity. To realize true energy saving in a wireless environment,the time varying property of the wireless channel should also be taken into account. Unfortunately, this factor has long been ignored in most existing state-of-the-art energy saving protocols. Neglecting the effects of varying channel quality can lead to an unnecessary waste of precious battery resources, and, in turn, can resultin the rapid depletion of sensor energy and partitioning of the network. In this paper, we propose a channel adaptiveenergy managementprotocol, called CAEM, that can exploit this time varying nature of the wireless link. Specifically, CAEM leverages on the synergistically cross-layer interaction between physical and MAC layers. Thus, each sensor node can intelligently access the wireless medium according to the current wireless link quality and the predicted traffic load, to realize an efficient utilization of the energy. Extensivesimulation results indicate that CAEM can achieve as much as 40% reductionin energy dissipation compared with traditional protocols without channel adaptation. © 2005 IEEE.published_or_final_versio

A NEW REDUCED SWITCH ZVS-PWM THREE-PHASE INVERTER

Dc-ac inverters convert a dc input voltage into a desired ac output voltage and are widely used in many industrial applications, including utility grid interfaces, motor drives, and wind energy systems. Because of their widespread use, there has been considerable interest to try to make them more efficient to conserve energy. One way of doing so is to reduce the losses that are generated by the switching of the inverter devices as they help convert the dc input voltage into an ac output. As a result, there has been considerable research into implementing inverters with so-called soft-switching - zero-voltage and zero-current switching techniques that make either the voltage across a switch or the current through it zero at the time of a switching transition (from on to off or off to on). Since the power dissipated in a switch is related to the amount of overlap of voltage and current during a switching transition, making either the switch voltage or switch current zero at this time can result in a significant reduction in switching losses. A new, reduced switch, zero-voltage switching (ZVS), three-phase dc-ac inverter is proposed in this thesis. The proposed inverter does not have the drawbacks that other previously proposed ZVS-PWM inverters have such as cost, increased conduction losses, the appearance of distortion in the output waveforms, and the lack of bidirectional operation capability. In the thesis, an extensive literature review of previously proposed soft-switched inverters is performed. The new inverter is then presented and its operation is explained in detail. The steady-state operation of the new inverter is analyzed and the results of the analysis are used to determine the converter\u27s steady-state characteristics. Based on these characteristics, a procedure for the design of the inverter is developed and then demonstrated with an example. Finally, the feasibility of the proposed converter and the validity of the analysis are confirmed with simulation results obtained from PSIM, a widely used, commercially available software simulation package for power electronic

Plans for the next GRAPE balloon flight

The Gamma RAy Polarimeter Experiment (GRAPE) was first flown on a 26-hour balloon flight in the fall of 2011. GRAPE consists of an array of Compton polarimeter modules (based on traditional scintillation technologies) designed to operate in the energy range from 50 keV up to 500 keV. The ultimate goal is to operate GRAPE in a wide FoV configuration for the study of gamma-ray bursts. For the first (demonstration) balloon flight, GRAPE was configured in a collimated mode to facilitate observations of known point sources. The Crab nebula/pulsar, the active Sun, and Cygnus X-1 were the primary targets for the first flight. Although the Crab was detected, the polarization sensitivity was worse than expected. This paper will review the plans for the next GRAPE balloon flight, which is scheduled to take place in the fall of 2014 from Ft. Sumner, NM. These plans involve several modifications designed to improve the polarization sensitivity, including an expansion of the array of polarimeter modules from 16 to 24 and improvements to the instrument shielding. Sensitivity estimates of the resulting instrument, based on GEANT4 simulations, will be presented

Implementation of Solar Irradiance Forecasting Using Markov Switching Model and Energy Management System

Photovoltaic (PV) systems integration is increasingly being used to reduce fuel consumption in diesel-based remote microgrids. However, uncertainty and low correlation of PV power availability with load reduce the benefits of PV integration. These challenges can be handled by introducing reserve, which however leads to increased operational cost. Solar irradiance forecasting helps to reduce reserve requirement, thereby improving the utilization of PV energy. In this thesis, a new solar irradiance forecasting method for remote microgrids based on the Markov Switching Model (MSM) is presented. This method uses locally available data to predict one-day-ahead solar irradiance for scheduling energy resources in remote microgrids. The model considers the past solar irradiance data, the Clear Sky Irradiance (CSI), and the Fourier basis functions to create linear models for three regimes or states: high, medium, and low energy regimes for a day corresponding to sunny, mildly cloudy, and extremely cloudy days, respectively. The case study for Brookings, SD, discussed in this thesis, resulted in an average Mean Absolute Percentage Error (MAPE) of 31.8% for five years, 2001 to 2005, with higher errors during summer months than during winter months. The solar irradiance forecasting method was implemented in OPAL-RT real-time digital simulator using PV panels as sensors. For forecasting irradiance, the first four hours of irradiance data in the morning are required. These data were measured using the solar panels rather than pyranometers as the sensors . A case study for real-time irradiance forecasting in Brookings on June 9, 2015 showed RMSE and MAPE of 131.08W=m2 and 45.45%, respectively. The improvement of renewable integration is the future and present prospects for power utilization. Microgrids experience several constraints such as integration of intermittent renewable sources, costlier reliability improvements, restricted expansion of the microgrid system, growth in load, etc. Hence, more research in this field of study is required and a complete laboratory scale microgrid testbed is needed for experimenting different types of microgrid topologies and for studying the coordination of individual components with a well-defined energy management scheme. In this thesis, the development of a laboratory scale single-phase microgrid testbed along with the implementation of microgrid’s Energy Management System (EMS) are discussed. The testbed was developed using central controller and Commercial Off-The-Shelf (COTS) equipment. The EMS comprised of double layers: schedule layer and real-time dispatch layer. A case study conducted for the implementation of the EMS showed that the difference in the scheduled and the dispatched powers were handled by the generator and the energy storage system themselves

GRAPE: a balloon-borne gamma-ray polarimeter

The Gamma-RAy Polarimeter Experiment (GRAPE) is a concept for an astronomical hard X-ray Compton polarimeter operating in the 50 - 500 keV energy band. The instrument has been optimized for wide-field polarization measurements of transient outbursts from energetic astrophysical objects such as gamma-ray bursts and solar flares. The GRAPE instrument is composed of identical modules, each of which consists of an array of scintillator elements read out by a multi-anode photomultiplier tube (MAPMT). Incident photons Compton scatter in plastic scintillator elements and are subsequently absorbed in inorganic scintillator elements; a net polarization signal is revealed by a characteristic asymmetry in the azimuthal scattering angles. We have constructed a prototype GRAPE module that has been calibrated at a polarized hard X-ray beam and flown on an engineering balloon test flight. A full-scale scientific balloon payload, consisting of up to 36 modules, is currently under development. The first flight, a one-day flight scheduled for 2011, will verify the expected scientific performance with a pointed observation of the Crab Nebula. We will then propose long-duration balloon flights to observe gamma-ray bursts and solar flares