High-quality power generation through distributed control of a power park microgrid

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Antenna Systems

This book offers an up-to-date and comprehensive review of modern antenna systems and their applications in the fields of contemporary wireless systems. It constitutes a useful resource of new material, including stochastic versus ray tracing wireless channel modeling for 5G and V2X applications and implantable devices. Chapters discuss modern metalens antennas in microwaves, terahertz, and optical domain. Moreover, the book presents new material on antenna arrays for 5G massive MIMO beamforming. Finally, it discusses new methods, devices, and technologies to enhance the performance of antenna systems

Power Management ICs for Internet of Things, Energy Harvesting and Biomedical Devices

This dissertation focuses on the power management unit (PMU) and integrated circuits (ICs) for the internet of things (IoT), energy harvesting and biomedical devices. Three monolithic power harvesting methods are studied for different challenges of smart nodes of IoT networks. Firstly, we propose that an impedance tuning approach is implemented with a capacitor value modulation to eliminate the quiescent power consumption. Secondly, we develop a hill-climbing MPPT mechanism that reuses and processes the information of the hysteresis controller in the time-domain and is free of power hungry analog circuits. Furthermore, the typical power-performance tradeoff of the hysteresis controller is solved by a self-triggered one-shot mechanism. Thus, the output regulation achieves high-performance and yet low-power operations as low as 12 µW. Thirdly, we introduce a reconfigurable charge pump to provide the hybrid conversion ratios (CRs) as 1⅓× up to 8× for minimizing the charge redistribution loss. The reconfigurable feature also dynamically tunes to maximum power point tracking (MPPT) with the frequency modulation, resulting in a two-dimensional MPPT. Therefore, the voltage conversion efficiency (VCE) and the power conversion efficiency (PCE) are enhanced and flattened across a wide harvesting range as 0.45 to 3 V. In a conclusion, we successfully develop an energy harvesting method for the IoT smart nodes with lower cost, smaller size, higher conversion efficiency, and better applicability. For the biomedical devices, this dissertation presents a novel cost-effective automatic resonance tracking method with maximum power transfer (MPT) for piezoelectric transducers (PT). The proposed tracking method is based on a band-pass filter (BPF) oscillator, exploiting the PT’s intrinsic resonance point through a sensing bridge. It guarantees automatic resonance tracking and maximum electrical power converted into mechanical motion regardless of process variations and environmental interferences. Thus, the proposed BPF oscillator-based scheme was designed for an ultrasonic vessel sealing and dissecting (UVSD) system. The sealing and dissecting functions were verified experimentally in chicken tissue and glycerin. Furthermore, a combined sensing scheme circuit allows multiple surgical tissue debulking, vessel sealer and dissector (VSD) technologies to operate from the same sensing scheme board. Its advantage is that a single driver controller could be used for both systems simplifying the complexity and design cost. In a conclusion, we successfully develop an ultrasonic scalpel to replace the other electrosurgical counterparts and the conventional scalpels with lower cost and better functionality

Power Electronics Applications in Renewable Energy Systems

The renewable generation system is currently experiencing rapid growth in various power grids. The stability and dynamic response issues of power grids are receiving attention due to the increase in power electronics-based renewable energy. The main focus of this Special Issue is to provide solutions for power system planning and operation. Power electronics-based devices can offer new ancillary services to several industrial sectors. In order to fully include the capability of power conversion systems in the network integration of renewable generators, several studies should be carried out, including detailed studies of switching circuits, and comprehensive operating strategies for numerous devices, consisting of large-scale renewable generation clusters

Advanced nonintrusive load monitoring system

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. 184-189).There is a need for flexible, inexpensive metering technologies that can be deployed in many different monitoring scenarios. Individual loads may be expected to compute information about their power consumption. Utility providers, facilities managers, and other consumers will likely find innumerable ways to mine information if made available in a useful form. However, appropriate sensing and information delivery systems remain a chief bottleneck for many applications, and metering hardware and access to metered information will likely limit the implementation of new electric energy conservation strategies in the near future. This thesis presents solutions for two long standing problems in nonintrusive power and diagnostic monitoring. First, a high-resolution, physically windowed sensor architecture that is well-suited for energy score-keeping and diagnostic applications will be discussed. The sensor can track a large-scale main signal while capturing small-scale variations. The prototype system uses digital techniques to reconstruct an observed current with a high effective bit resolution. The sensor measures a small current signal using a closed-loop Hall sensor. and extends the range by driving a compensation current with a high performance current source through an auxiliary winding. The system combines the compensation command and the sampled output of the residual sensor to reconstruct the input signal with high bit resolution and bandwidth. Second, a long-standing problem in nonintrusive power monitoring involves the tracking of power consumption in the in the presence of loads with a continuously variable power demand. Two new techniques have been developed for automatically disaggregating, in real-time. different classes of continuously variable power electronic loads which draw distorted line currents. Experimental results of the proposed power estimator extracting the power consumption of common variable power loads such as a variable speed drive, a computer, and a light dimmer are presented.by Warit Wichakool.Ph.D

Analysis of electric propulsion electrical power conditioning component technology. Volume 1 - Data bank Final report

Analysis of electric propulsion electric power conditioning component technology - data revie

Microprocessor controlled novel 4-quadrant DC-DC converter

The thesis describes a novel 4-quadrant DC-DC converter, supplied by a 28V DC voltage source, with an output voltage which may be continuously varied between +180V and -180V DC. A prototype 1.2kW DC-DC converter was designed and built, with emphasis given to the optimization of both the converter size and efficiency. This was achieved by means of a computer-based simulation study, which determined the optimal switching frequency and the size of the inductors and capacitors while maintaining a high unit efficiency. Mos-Gated Bimos switches, which feature the advantages of both mosfets and bipolar transistors, were developed to achieve high switching speed during high power operation. A digital-controlled DC servo system based on a 16-bit Intel 8086 microprocessor was designed, to provide both motor speed and position control. Speed and position detection circuits and the structure and the interfacing arrangement of the microprocessor system were designed and constructed. Several control algorithms were developed, including PID Control Algorithm and Current-Limit Control Algorithm. Based on open loop transfer function of the system, derived through mathematical modelling using the State-Space Averaging Method, the constants for the control algorithms were obtained to meet the dynamic performance specified for the system. Computer simulation was carried out to assist with the design of the converter and the control system. It is expected that drives into which the novel converter is incorporated will find many applications in situations where accurate positional control is required, particularly in battery-operated DC-servo system, such as satellite system, robots and some military vehicles

Fault tolerant electromechanical actuators for aircraft

This thesis reviews the developments in commercial aviation resulting from More Electric Aircraft initiatives. The present level of electromechanical actuation is considered with discussion of the factors affecting more widespread use. Two rather different electromechanical actuators are presented for commercial aircraft; DEAWS electrical flap actuation and ELGEAR nose wheel steering. Both projects are industrially driven with specifications based on existing medium-sized commercial aircraft. Methods comparing fault tolerant electric drive topologies for electrical actuators are presented, showing two different categories of electric drive and comparing each category in a variety of operating conditions to assess size and component count. The safety-driven design process for electromechanical actuators is discussed with reliability calculations presented for both proposed actuators, showing where fault tolerant design is required to meet safety requirements. The selection of an optimum fault tolerant electric drive for each actuator is discussed and fault tolerant control schemes are presented. The development of the electric flap and nose wheel steering systems is described, with the focus on the work performed by the author, primarily on the power electronic converters and control software. A comprehensive range of laboratory and industrial results are given for both actuators, showing demonstrations of fault tolerance at power converter and actuator levels. Following testing, further analysis is given on various issues arising prior and during testing of both converters, with design considerations for future electromechanical actuators. From design testing and analysis, the two projects can be compared to attempt to determine the optimal electromechanical actuator topology and to consider the challenges in evolving the two actuators to aerospace products.EThOS - Electronic Theses Online ServiceEPSRC : DTIGBUnited Kingdo