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We report on high power microwave (HPM) susceptibility tests of vulnerable IT network components. The devices under test are five different commercial and industrial media converters, one military media converter and a shielded enclosure for commercial media converters. The report compares results of susceptibility tests in different configurations supplemented by transfer function measurements.

Over the past several years, energy efficiency and power density have become the top concerns for power conversion. Rising energy intensity leads to a higher cost of delivering power. Meanwhile, the demand for compact power supplies grows significantly. It requires power supplies with high efficiency, low profile and high power density. Dc-dc power conversion has been widely applied for industry, medial, military and airspace applications. Conventional PWM dc-dc converters have relatively low power transfer efficiency and low power density. In contrast, resonant dc-dc converters have numerous advantages for dc-dc power conversions. In this work, topologies and system optimization of resonant converters are investigated to meet challenges of high efficiency, high power density, low EMI, easy startup and over current protection. LLC resonant converters can achieve zero-voltage-switching (ZVS) for primary side devices and zero-current-switching (ZCS) for the secondary side rectifiers. The switching loss is minimized. LLC is very attractive to overcome the issues of conventional circuits. However, challenges still remain. First of all, for low-voltage high-current applications, the synchronous rectifier (SR) with lower conduction loss is a must for high efficiency. To solve the driving issues of SRs, a novel synchronous driving scheme is proposed. Experimental results demonstrate the considerable loss reduction with utilization of the proposed driving scheme. Secondly, dc-dc converters are required to meet EMI standard. This work proposes an EMI mode. Based on the proposed model, EMI analysis and noise attenuation techniques are proposed and verified by experiments. Thirdly, startup and over-load protection are another issues of LLC resonant converters. With proposed multi-element resonant converters, the current limit issues can be resolved. In addition, the proposed multi-element resonant converters can utilize higher-order harmonics to enhance power transfer. Fourthly, for high-current applications, the secondary side structure becomes very critical. An improved secondary side construction is proposed to alleviate ac termination losses and SR paralleling issues. Novel winding structures are proposed to reduce the winding loss. The magnetic integration technique is proposed and analyzed, and an optimal integrated transformer design is proposed, which has low loss and compact size. ; Ph. D.

The aim of this investigation is to consider the internal processes in the contact zone of the semiconductor
with radionuclide microalloying: the diffusion of atoms during endotaxy, the diffusion of atoms after the decay of
radionuclides, the formation of electrons and the material features arising from such diffusion. The DFT approach
in this paper is aimed at obtaining evidence of the vacancy mechanism of diffusion. Radionuclide atoms diffuse
into the growing layer of silicon carbide on silicon at the level of isoelement microalloying, forming, depending
on the phase, effects that energetically manifest themselves as the effect of the «inner sun», which is the source
of the spectrum of primary electrons and secondary electron-hole pairs at ionization losses. This is due to the
interaction with the electrons of the shells of neighboring atoms, generating secondary electrons and holes in
the region of spatial charge, carried by built-in electric fields.

1. Survey of the Existing Analysis Methods -- 1. Introduction to the Injected-Absorbed-Current Method of Analysis -- 2. Elementary Converters Operating at Constant Frequency with Duty Ratio as Controlled Quantity -- 3. General Small-Signal, Low-Frequency Analysis of Switching Regulators -- 4. State-Variables-Averaging Method -- 2. Multiple-Loop Switching Power Cells -- 5. Elementary Switching Power Cells with Inductor Current as Controlled Quantity -- 6. Multiple-Loop Switching Cells Using Inductor Voltage in a Minor Feedback Loop -- 3. Special Configurations -- 7. ?uk and SEPIC Switching Cells -- 8. Analysis of Power Cells with Duty-Ratio Control at Variable Frequency -- 9. Free-Running Hysteretic Regulator -- 4. Applications of Linear Analysis Method -- 10. Interconnection of a Power Source and a Switching Regulator -- 11. Feedforward in Switching Regulators -- 12. Parallel Operation of Switching Regulators -- 5. Selected Analytic Approaches and Applications and Future Advances in Analysis Methods -- 13. Selected Analysis Examples -- 14. High-Frequency Extension of the Linear Cell Model -- Appendixes -- Appendix 1. Additional Information for Chapter 5 -- A1-1 Derivation of Time Delay Between Control and Injected Current for Constant Off Time Current-Mode Control -- A1-2 Control-to-Output Voltage Functions of CurrentMode-Controlled Buck Converter with Three Different Control Methods -- Appendix 2. Graphical-Analytical Representation of Transfer Functions -- A2-1 Introduction -- A2-2 Transfer Functions of Passive Networks -- References -- Appendix 3. Examples and Problems -- A3-1 Introduction -- A3-2 Appendix to Chapter 2—Regulators Employing Elementary Cells, Operating at Constant Switching Frequency, and with Duty Ratio as the Controlled Quantity -- A3-3 Appendix to Chapter 14—Successive Approximations of the Cell Controlled-Quantity-to-Output-Voltage Transfer Function -- Appendix 4. Sources of Technical Information -- A4-1 Conferences -- A4-2 Periodicals -- A4-3 Compendia -- A4-4 Textbooks.

Note: This is a preprint of paper #1914 presented at the 14th European Wave & Tidal Energy Conference (EWTEC) 2021 in Plymouth, UK. The final version of paper with the same title can be found in the EWTEC 2021 proceedings. Abstract: Lift-based Wave Energy Converters (WECs) have a number of attractive features, including the potential for unidirectional rotation, simplifying power take-off and reduction in wave loads by reducing generation of circulation, increasing survivability. The common assumption of small body, small amplitude response, together with the Haskinds Relationship is used to determine the optimum motion for a lift-based WEC to maximise power capture. It is shown that whilst for a 2D hydrofoil in deep water the optimum motion is circular, the optimum motion for a finite-width hydrofoil is generally elliptical due to differences in the hydrodynamic damping coefficients associated with the vertical and horizontal motions of the hydrofoil. It is shown that more circular hydrofoil motion can be achieved by utilising the elliptical motion of the water particles in shallow water. This occurs because the increased horizontal water particle motion in shallow water results in an increase in the wave-induced lift force associated with horizontal fluid particle motions, and thus a reduction in the optimum amplitude of motion in this direction. Preliminary calculations suggest that for a 30 metre wide hydrofoil in wave periods of about 10 seconds, the ideal water depth (where the optimum hydrofoil motion is circular) occurs at around 25 metres, which is a highly utilisable water depth. Other advantages of deployment in shallower water include an improvement in the alignment of the waves parallel to the hydrofoil and a reduction in the structural task associated with reacting against the seabed. ; This work was produced as part of the LiftWEC Project. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 851885. This output ...

none ; 2 ; Authors: Graditi G., Adinolfi G., Tina G.M. ; Objective: Photovoltaic (PV) systems can operate in presence of not uniform working conditions caused by continuously changing temperature and irradiance values and mismatching and shadowing phenomena. The more the PV system works in these conditions, the more its energy performances are negatively affected. Distributed Maximum Power Point Tracking (DMPPT) converters are now increasingly used to overcome this problem and to improve PV applications efficiency. A DMPPT system consists in a DC-DC converters equipped with a suitable controller dedicated to the Maximum Power Point Tracking (MPPT) of a single PV module. It is arranged either inside the junction-box or in a separate box close to the PV generator. Many power optimizers are now commercially available. In spite of different adopted DC-DC converter topologies, the shared interests of DMPPT systems designers are the high efficiency and reliability values. It is worth noting that to obtain so high performances converters, electronic components have to be carefully selected between the whole commercial availability and appropriately matched together. In this scenario, an electro-thermal design methodology is proposed and a reliability study by means of the Military Handbook 217F is carried out. Method: The developed DMPPT converters design method is constituted by many steps. In fact, beginning from installation site, PV generators and load data, this process selects power optimizers commercially available devices and it verifies their electro-thermal behavior to the aim to identify a set of suitable components for DMPPT applications. Repeating this process many times, many different feasible solutions can be found. An elaboration step follows to the "optima" power optimizer recognition among the whole obtained converters. In this case, a multi-objective optimization, consisting in the maximization of the solutions European efficiency and in the minimization of their cost, is executed and all not ...