Built-in Converter Research Articles

The Potential Environmental and Social Influence of the Inorganic Salt Hydrates Used as a Phase Change Material for Thermal Energy Storage in Solar Installations.

The aim of this article is to assess the potential impact of inorganic salt hydrates used as PCM material in solar installations on the environment and human health and to assess the society's approach to this technology. The properties of salt are discussed in two ways: first, by analyzing the environmental and health problems caused by chemical hazards on the basis of the available material safety data sheets. Secondly, by analyzing the potential disadvantages of salt hydrates in terms of environmental hazards based on the results of experimental studies available in the literature. Then, using questionnaires, the public approach to solar installations with a built-in converter containing salt hydrates is assessed. Disodium hydrogen phosphate dodecahydrate turned out to be the most prospective salt in terms of environmental, thermophysical, and economic properties for use in solar installations. Understanding the attitudes of the local community toward technologies using inorganic salt hydrates will enable appropriate action to be taken in the future to promote their development. Surveys have shown great public concern about their impact on the environment and human health. In this regard, it is necessary to implement information and promotion activities.

Harnessing vibration energy from a rice-milling machine

In the advent of a rat race for the exploration of alternative source of power, clean and green source of electrical power is deemed to be an extreme priority. Various groups of people, professionals and even students with wide spectrum of discipline untiringly continue to source-out electricity out of their own exploration capabilities. This study had focused on the extraction and conversion of a vibration energy from a moving strainer mechanism of a rice-milling machine. The researchers of this project undertaking were able to successfully fabricate a prototype that can extract the vibration energy from the said mechanism. The harnessed vibration energy was then converted to a usable electricity via a built-in converter circuit of the said prototype. The prototype was successfully tested in a local rice mill. The device was found to fully - charge a smart phone with an initial charge of five (5) per cent and to within a span of three (3) continuous hours. The device was also found to yield a maximum charging current of 500 milliamperes.

Integrated buck and boost converter for a universal battery charger of an Electric Vehicle

A two-stage converter connects the input grid voltage to a pack of batteries with the voltage varying between 48-400 V, depending on the size and the range of the vehicle, with battery-operated electric and Plug-in Hybrid Electric Vehicles (PHEVs). This article offers a unique built-in converter that can interface with both high voltage (HV) and low voltage (LV) batteries. For all car architectures a universal charger that can accommodate this wide range of battery pack voltages is suitable. The novel integrated buck and boost converter (IBBC) is the proposed converter supplied using AC-DC driver at the front end mode. The main objective of this paper is to show a universal battery charger for an EV with a high power factor (PFC) and a small total harmonic distortion (THD) in addition to the high power density. A PFC converter is formed without any auxiliary circuit to balance the output voltage dependence of the battery against fluctuations in the ac grid input voltage, which in turn reduces the cost of additional circuit. A closed loop controller scheme is used to adjust for variations in the broad range output voltage and load. The proposed topology’s detailed operation is simulated using the MATLAB/Simulink software and achieved a THD of 1.18%.

Refining ACES Best Practice

ACES is the Academy Color Encoding System established by the Academy of Motion Picture Arts and Science (A.M.P.A.S). Since its introduction (version 1.0 in December 2014), it has been widely used in the film industry. The interaction of four modules makes the system flexible and leaves room for own developments and modifications. Nevertheless, improvements are possible for various practical applications. This paper analyzes some of the problems frequently encountered in practice in order to identify possible solutions. These include improvements in importing still images, white point conversions problems and test lighting. The results should be applicable in practice and take into account above all the workflow with commercially available software programs. The goal of this paper is to record the spectral distribution of a GretagMacbeth ColorChecker using a spectrometer and also photography it with different cameras like RED Scarlet M-X, Blackmagic URSA Mini Pro and Canon EOS 5D Mark III under the same lighting conditions. The recorded imagery is then converted to the ACES2065-1 color space. The positions of the patches of the ColorChecker in CIE Yxy color space are then compared to the positions of the patches captured by the spectral device. Using several built-in converters the goal is to match the positions of the spectral data as close as possible

Design of Testing & Identification System for Recovery Material of Launch Control Device of Certain Missile

This article presents a method for testing and identification of a recovery material of certain missile, systematically analyzes the diagnostic approach and technology of PCB faults, expounds in detail design concept of the system, sets forth the solution using C8051F020 chip as microprocessor and testing of analog and digital I/O with built-in converter, contrives polarity discrimination circuit, provides software design process and main program by means of design thinking of modularized software, which help increasing program reliability and lowering development cost. The experimentation proves that this system is able to precisely position the faulty module of PCB to be identified, as well as make correct and reasonable opinion for maintenance. The design method and concept of this article is of significant value for reference in the research and development of similar testing and identification system.

Boundary Element Analysis of Reactive Mufflers and Packed Silencers with Catalyst Converters

This paper reviews recent developments in the application of the boundary element method (BEM) to muffler and silencer analysis. Initial results of modeling built-in catalyst converters are also presented. A so-called “direct mixed-body boundary element method� has been developed for muffler and silencer analysis since 1996. The idea of the method is to integrate all kinds of different boundary and internal surfaces into a single integral equation set without using the conventional multi-domain approach, even though there may be different media in the domain. A key ingredient in this method is the hypersingular integral equation. The concept of the direct mixedbody BEM is not totally against the conventional multi-domain BEM, though. For very large structures or at high frequencies, a multi-domain or substructuring approach is still necessary in order to reduce the memory usage as well as the computation time. With the direct mixed-body BEM, each substructure does not need to be a well-defined and homogeneous subdomain. As such, substructuring can be done more naturally along the longitudinal direction. Catalyst converters may also be modeled as a modular in the general framework of substructuring. Several test cases are presented with experimental verification, including two cases with built-in converters.

Increasing Power and Efficiency of Gyrotrons

Until recently, the development of new gyrotrons was directed mainly at the increase of their operating frequency, power, and efficiency. The output power of modern continuous-wave (cw) gyrotrons has reached 1 MW, and there is a clear tendency to increase this power further to at least up to 1.5 to 2 MW. The efficiency of the best gyrotron tubes reaches 40% without recovering the residual energy of the spent electron beam [collector potential depression (CPD)] in the continuous regimes and 50% in the pulsed one and achieves 50% with one-step CPD in the cw regimes and near 70% in the pulsed regimes. We analyze limitations of the gyrotron output power and efficiency imposed by systems forming helical electron beams, the cavity interaction processes, the transmitting capability of the output window, and the losses of stray radiation in the built-in converter and power dissipation on the collector (including CPD). Some specific examples in applying the different limits to real cases of gyrotrons are discussed. Ways to enhance the power and efficiency of gyrotrons based on the results of this analysis are shown.

Mode Converter Synthesis by the Particle Swarm Optimization

Particle Swarm Optimization (PSO) is an effective, simple and promising method intended for the fast search in multi-dimensional space [1]. Besides special testing problems a number of engineering tasks of electrodynamics were solved by the PSO successfully [2,3]. On the other hand, the scattering matrix technique is a fast and accurate method of mode converter analysis. We illustrate PSO by a number of converter designs intended for high-power microwaves control: a matching horn for maser section, a design of built-in converter for multi-charged ion source, a TE01 miter bend.

The gyrotron: Constraints on output-power and efficiency increase

With allowance for the results of national and foreign gyrotron developments, we analyze constraints on the gyrotron efficiency and output power stipulated by the properties of the electron beam, the processes in a resonant cavity, the output-window throughput, the scattered-radiation losses in a built-in converter, and the energy release on a collector. A comparative estimate of the influence of the factors limiting the gyrotron power and efficiency is given.

Recent progress of high-power millimeter wavelength gyrodevices

This presentation reviews recent progress of Russian physicists in developing electronic devices of the gyroresonance type, which are so far the most advanced sources of millimeter microwaves. It deals with the concept of the gyrotron as a device operating at higher volume resonator modes with a built-in quasioptical converter of the output radiation into a wave beam. That concept made it possible to create comparatively simple and reliable long-pulse and quasicontinuous devices with a power level of 0.5 MW in the frequency band 30–160 GHz. Analysis of the principal problems of projects for continuous-wave (CW) gyrotrons of near 1 MW output power (choice of an operating mode, requirements to an electron beam, peculiarities of built-in converters) is included, as well as the results of model experiments. For amplifying millimeter wavelength gyroklystrons, a level of several hundreds of kW at the frequency 35 GHz, and up to 65 kW at frequency 94 GHz were also achieved. Some modifications of gyrotrons for material processing and special research are described.