Designs for ultra-high efficiency grid-connected power conversion

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 213-215).Grid connected power conversion is an absolutely critical component of many established and developing industries, such as information technology, telecommunications, renewable power generation (e.g. photovoltaic and wind), even down to consumer electronics. There is an ever present demand to reduce the volume and cost, while increasing converter efficiency and performance. Reducing the losses associated with energy conversion to and from the grid can be accomplished through the use of new circuit topologies, enhanced control methods, and optimized energy storage. The thesis outlines the development of foundational methods and architectures for improving the efficiency of these converters, and allowing the improvements to be scaled with future advances in semiconductor and passive component technologies. The work is presented in application to module integrated converters (MICs), often called micro-inverters. These converters have been under rapid development for single-phase gridtied photovoltaic applications. The capacitive energy storage implementation for the double-line-frequency power variation represents a differentiating factor among existing designs, and this thesis introduces a new topology that places the energy storage block in a series-connected path with the line interface. This design provides independent control over the capacitor voltage, soft-switching for all semiconductor devices, and full four-quadrant operation with the grid.by Brandon J. Pierquet.Ph.D

High voltage power supply for a small plasma spectrometer

Thesis (M.S.) University of Alaska Fairbanks, 2023This thesis describes the design, manufacturing, and testing of a high voltage power supply for an electron spectrometer to be used on a small spacecraft. The challenge was reducing complexity, size, and power consumption enough to be useful for a CubeSat or a sounding rocket sub-payload. The power supply has two purposes: i) it produces DC at roughly 2000 V for a microchannel plate detector and ii) it produces exponential voltage sweeps from about +4000 V to below 5 V for an electrostatic analyzer. This power supply uses solid state relays for a charge pump and for producing voltage sweeps with capacitive discharge. The detector power supply is software and hardware regulated to provide tunable output up to 2400 V, with voltage drift and ripple of around ±1%. The power supply is managed by an MSP430 microcontroller. It includes several automatic, hardware-based, closed-loop controls to stabilize performance across a range of temperatures, input voltages, and component parameters. All digital switching, signal changes, measurements, and monitoring are done in a single control loop. The design includes thermal protection, current limiting, a hardware watchdog, transient voltage suppression, and hardware-based overvoltage protection. The circuits survived thermal vacuum testing, operating within specifications for several weeks during many cycles of -40 °C to +70°C. The supply operated a real spectrometer inside an electron beam chamber. The consistent voltage sweeps allowed the spectrometer to accurately distinguish electron beam energies. This power supply is a successful proof of concept for powering a microchannel plate detector and an electrostatic analyzer at over 4000 V using a single 64 mm diameter circuit board, consuming 0.5 W or less from a small spacecraft.Chapter 1. Introduction -- Chapter 2. Overall design basics -- Chapter 3. ESA sweeping supply -- Chapter 4. MCP detector supply and converter control -- Chapter 5. Microcontroller and associated electronics -- Chapter 6. Circuit protections -- Chapter 7. HVPS board design -- Chapter 8. Testing results -- Chapter 9. Dead ends and unfinished ideas -- Chapter 10. Conclusions and future ideas -- References

An optimized routing algorithm for data collection in IoT network

This thesis has as a principal objective the resolution of a problem present in the Internet of Things (IoT) network. This problem is the routing optimization of the data between the sensors and the gateway, which is not optimized these days in the current applications of the IoT. The project is attacked mainly from a theoretical point of view and so several hypotheses are done to carry it out, but it leads to a generalized solution valid for different IoT applications. The network is pictured as a graph in which the sensors and the gateway are the nodes and the connections between them are the links. More specifically, the thesis uses an algorithm widely used in the transportation network, the Clarke & Wright’s Savings Algorithm, and adapts it to the data network. This algorithm is based in the savings of putting two or more nodes in the same route comparing it to the case where all sensors send directly their data gathered to the gateway. The algorithm starts with the pair of nodes that imply the highest saving if both were at the same route, and with their constraints the code determines if this merge is feasible or not. The same process is done for all the pairs of nodes (picking them from maximum savings value to the minimum) until all nodes are connected to another one. The solution of the algorithm is compared with three other solutions: two base lines and the exact solution extracted from the software CPLEX. The first base line depicts the solution in which every node sends directly to the gateway (no algorithm applied), and the second base line is similar to the actual algorithm proposed but with limiting to 2 nodes maximum connected before reaching the gateway. After obtaining a total number of 500 solutions (from 2 to 100 nodes), the algorithm was 475 times better than the BL with an average percentage of improvement of 36,54% out of the 475, and 329 times better than the BL2 with the same percentage this time of 0,91% out of the 329. When comparing the algorithm with the CPLEX solution, a number of 52 cases were tested and this reduced number is due to its elevated execution time reaching the 100h of resolution for certain cases with less than 30 nodes. Out of these 52, only 13 of them the CPLEX solution was better than the algorithm and out of the 13 the average percentage of improvement is of 5,21%.Outgoin

Smart Wireless Sensor Networks

The recent development of communication and sensor technology results in the growth of a new attractive and challenging area - wireless sensor networks (WSNs). A wireless sensor network which consists of a large number of sensor nodes is deployed in environmental fields to serve various applications. Facilitated with the ability of wireless communication and intelligent computation, these nodes become smart sensors which do not only perceive ambient physical parameters but also be able to process information, cooperate with each other and self-organize into the network. These new features assist the sensor nodes as well as the network to operate more efficiently in terms of both data acquisition and energy consumption. Special purposes of the applications require design and operation of WSNs different from conventional networks such as the internet. The network design must take into account of the objectives of specific applications. The nature of deployed environment must be considered. The limited of sensor nodes� resources such as memory, computational ability, communication bandwidth and energy source are the challenges in network design. A smart wireless sensor network must be able to deal with these constraints as well as to guarantee the connectivity, coverage, reliability and security of network's operation for a maximized lifetime. This book discusses various aspects of designing such smart wireless sensor networks. Main topics includes: design methodologies, network protocols and algorithms, quality of service management, coverage optimization, time synchronization and security techniques for sensor networks

Enhanced Living Environments

This open access book was prepared as a Final Publication of the COST Action IC1303 “Algorithms, Architectures and Platforms for Enhanced Living Environments (AAPELE)”. The concept of Enhanced Living Environments (ELE) refers to the area of Ambient Assisted Living (AAL) that is more related with Information and Communication Technologies (ICT). Effective ELE solutions require appropriate ICT algorithms, architectures, platforms, and systems, having in view the advance of science and technology in this area and the development of new and innovative solutions that can provide improvements in the quality of life for people in their homes and can reduce the financial burden on the budgets of the healthcare providers. The aim of this book is to become a state-of-the-art reference, discussing progress made, as well as prompting future directions on theories, practices, standards, and strategies related to the ELE area. The book contains 12 chapters and can serve as a valuable reference for undergraduate students, post-graduate students, educators, faculty members, researchers, engineers, medical doctors, healthcare organizations, insurance companies, and research strategists working in this area

The Fifth NASA Symposium on VLSI Design

The fifth annual NASA Symposium on VLSI Design had 13 sessions including Radiation Effects, Architectures, Mixed Signal, Design Techniques, Fault Testing, Synthesis, Signal Processing, and other Featured Presentations. The symposium provides insights into developments in VLSI and digital systems which can be used to increase data systems performance. The presentations share insights into next generation advances that will serve as a basis for future VLSI design

A general framework for IoT-ready geotechnical objects

The project focuses on the relationship between current IoT trends and geotechnics within the civil engineering context. A simple framework for geotechnical data exchange tailored to IoT applications, potentially suitable for both small to large scale structural and infrastructural scenarios, has been prototyped. Within such scenarios further a special case of data generation from sensor-enabled geosynthetics has been explored. Additionally, different modelling and analytics strategies, based both on FEA procedures and Machine Learning algorithms, have been developed to provide the necessary data-to-knowledge tools to complement the framework

Towards a Conceptual Design of an Intelligent Material Transport Based on Machine Learning and Axiomatic Design Theory

Reliable and efficient material transport is one of the basic requirements that affect productivity in sheet metal industry. This paper presents a methodology for conceptual design of intelligent material transport using mobile robot, based on axiomatic design theory, graph theory and artificial intelligence. Developed control algorithm was implemented and tested on the mobile robot system Khepera II within the laboratory model of manufacturing environment. Matlab© software package was used for manufacturing process simulation, implementation of search algorithms and neural network training. Experimental results clearly show that intelligent mobile robot can learn and predict optimal material transport flows thanks to the use of artificial neural networks. Achieved positioning error of mobile robot indicates that conceptual design approach can be used for material transport and handling tasks in intelligent manufacturing systems

Friction Force Microscopy of Deep Drawing Made Surfaces

Aim of this paper is to contribute to micro-tribology understanding and friction in micro-scale interpretation in case of metal beverage production, particularly the deep drawing process of cans. In order to bridging the gap between engineering and trial-and-error principles, an experimental AFM-based micro-tribological approach is adopted. For that purpose, the can’s surfaces are imaged with atomic force microscopy (AFM) and the frictional force signal is measured with frictional force microscopy (FFM). In both techniques, the sample surface is scanned with a stylus attached to a cantilever. Vertical motion of the cantilever is recorded in AFM and horizontal motion is recorded in FFM. The presented work evaluates friction over a micro-scale on various samples gathered from cylindrical, bottom and round parts of cans, made of same the material but with different deep drawing process parameters. The main idea is to link the experimental observation with the manufacturing process. Results presented here can advance the knowledge in order to comprehend the tribological phenomena at the contact scales, too small for conventional tribology