Analysis of Wireless Power System Efficiency in Dependency on Configuration of Resonant Tank

This chapter compares various compensation methods for resonant coupling of the wireless energy transfer system. A proposed analysis is particularly relevant to any application where contactless battery charging is used. Main parameters that are investigated include efficiency and electrical variables (current and voltage) of the circuit. In order to analyze the most suitable solution of coupling compensation, the relevant equations are graphically interpreted for each discussed circuit topology. Finally, this chapter provides the recommendations how to design the wireless power-transfer system with the highest possible efficiency for the given system parameters (switching frequency and transmitting distance)

Sine Wave Filters Design for AC Motor Drives with Genetic Algorithms

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Light pulsed irradiation in growing seedlings

This work presents the research results of dynamic characteristics of ARPL-1W LEDs with a narrow-spectrum composition of luminescence (red, green, blue) using switching power supply of U-shaped pulses. Based on the results of increase and decrease of light flux and analysis of the kinetics of photosynthetic processes, from light absorption to absorption of CO2 from the atmosphere and the formation of carbohydrates, the LED irradiation installation is designed and approbated for growing seedlings. According to the results of experimental studies it is shown that pulsed irradiation stimulates faster plant growth without losing their morphometric parameters

Bacteremias caused by Escherichia coli in cancer patients — analysis of 65 episodes

AbstractObjectives: The aims of this study were to evaluate risk factors, clinical presentation, outcome and antimicrobial susceptibility in patients with Escherichia coli bacteremia occurring over seven years in a single cancer hospital.Methods: Sixty five episodes of bacteremia from E. coli appearing over seven years from 12,301 admissions in a single cancer institution were retrospectively analyzed.Results: The proportion of bacteremia caused by E. coli among Gram-negative bacteremia was 20.8% (the second most common organism after Pseudomonas aeruginosa), and infection-associated mortality was 17%.The incidence in 1989–1995 varied from 14.3 to 24.7%. The most common risk factors were: solid tumors as the underlying disease (70.7%); central venous catheter insertion (32.3%); prior surgery (46.2%), and prior chemotherapy within 48 h (44.4%). Neutropenia and urinary catheters did not place patients at high risk in any of the subgroups. When we compared the two subgroups of 61 cases of bacteremia — monomicrobial and polymicrobial (when E. coli was isolated from blood culture with another microorganism) — we found that acute leukemia and breakthrough (recurrence while receiving antibiotics) bacteremia were more frequently associated with polymicrobial E. coli bacteremia. There was also a difference in infection-associated mortality: monomicrobial bacteremia due to E. coli only had a significantly lower mortality in comparison with polymicrobial E. coli bacteremia (8.9 vs 35.0%, respectively; P<0.03).Conclusion: The susceptibility of 115 E. coli strains isolated from 65 episodes of bacteremia was stable. Only two episodes caused by quinolone-resistant strains occurred, both in 1995, after six years of using ofloxacin for prophylaxis in neutropenic patients in our hospital. We found that 85.2–91.3% of all strains were susceptible to aminoglycosides, 97.8% to quinolones, and 90–100% to third generation cephalosporins and imipenems.The patients most commonly infected had solid tumors and the mortality was only 17%

Application of Communication Systems in Biomedical Engineering

Picture archiving and communication systems (PACS) in biomedical engineering consist of image and data acquisition, storage, and display subsystems integrated by various digital networks. The standard (DICOM 3) is applicable to a networked or an off-line media environment. It allows development and expansion of PACS system. This Standard has been developed with an emphasis on diagnostic medical imaging as practiced in radiology, cardiology and related disciplines. Also the compression methods suitable for image processing are presented in this article. The compression is often realized by reduction of irrelevance or redundancy. There are described lossless and lossy compression methods which can be used for compression of images in biomedical applications and comparison of these methods based on fidelity criteria

Improvement of Power Electronic Structure Characteristics Using Sic Technology - Overview

This paper is dedicated to the recent unprecedented boom of SiC electronic technology. The contribution deals with a brief survey of those properties. In particular, the differences (both good and bad) between SiC electronics technology and well-known silicon VLSI technology are highlighted. Projected performance benefits of SiC electronics are given for several large-scale applications at the end of the contribution. The basic properties of SiC material were discussed already at the beginning of 1980's, also in our work place [1]

Usign Planar Transformers in Soft Switching DC/DC Power Converters

In recent years, the demand for wide applications of highly regulated, reliable power supplies, and the desire to have smaller size, lighter weight and higher efficiency of power electronics systems has been increased. The tallest and heaviest components on printed-circuit-boards are often magnetic components. The answer for miniaturization and material performance can be planar magnetic technology. This paper focuses on the power planar magnetic circuits, with respect to application possibilities of these alternative and attractive magnetic components in modern, soft switching, low profile power supplies

Optimalization of IGBT Communication

The paper presents IGBT switch off process in order to reduce power loss in the structure. The soft switching method using switch-off after current reduction is used. Process mentioned above is optimized to minimize the power loss that is determined by experiment. Results obtained in the experiment can be helpful in a converter and controller design process

Voltage Stress Reduction on Compensation Capacitors of Wireless Charging Systems for Transport and Industrial Infrastructure

The paper deals with a proposal for circuit configuration of series-series (SS) compensated wireless power transfer (WPT) system with reduced voltage stresses on compensation capacitors. Nowadays, a huge effort is given for the development of reliable, efficient and robust wireless charging systems and therefore the circuit configuration and component selection are crucial to meet suitable operational characteristics. For this purpose, the current trends in WPT systems are outlined in the first section. Next, the analysis of frequently utilized WPT system configuration is provided and the most critical issues related to practical utilization are discussed. Consequently, the proposal of how to eliminate negative aspects is given. All theoretical statements are supported by mathematical apparatus of the proposed system and consequently by the simulation analysis

Battery Charging Procedure Proposal Including Regeneration of Short-Circuited and Deeply Discharged LiFePO4 Traction Batteries

The presented paper discusses the most often damages applying for lithium traction and non-traction cells. The focus is therefore given on investigation of possibilities related to the recovery of such damaged lithium-ion batteries, more specifically after long-term short-circuit and deep discharge. For this purpose, initially, the short-circuit was applied to the selected type of traction LiFePO4 cell. Also, the deeply discharged cell was identified and observed. Both damaged cells would exhibit visible damage if electro-mechanical properties were measured. Individual types of damage require a different approach for battery regeneration to recover cells as much as possible. For this purpose, experimental set-up for automated system integrating proposed recovery methods were realized, while battery under test undergone a full-range of regeneration procedure. As a verification of the proposed regeneration algorithms, the test of delivered Ampere-hours (Ah) for various discharging currents was realized both for short-circuited as well as deeply discharged cells. Received results have been compared to the new/referenced cell, which undergoes the same test of delivered Ah. From the final evaluation is seen, that proposed procedure can recover damaged cell up to 80% of its full capacity if short-circuit was applied, or 70% if a deeply discharged cell is considered