Wyniki 11-20 spośród 21 dla zapytania: authorDesc:"Paweł KOMADA"

### Development of simulation model of electric drive of decoiler DOI:10.12915/pe.2014.11.45

Czytaj za darmo! »

The article is devoted to questions of building of uncoiler electric drive simulation model at rolling mill. Model detects current, moment, electro driving power, magnetic flow and engine rotation speed. Streszczenie. Artykuł poświęcony jest modelowaniu numerycznym napędu elektrycznego walcarki. Model pozwala na określenie prądu, momentu, mocy napędowej, strumienia magnetycznego i prędkości obrotowej silnika. (Opracowanie modelu symulacyjnego napędu elektrycznego rozwijarki). Keywords: numerical simulation, electric drive, rolling mill. Słowa kluczowe: symulacja numeryczna, napęd elektryczny, walcarka. doi:10.12915/pe.2014.11.45 Statement of the Problem In sheet rolling mills there is important to adjust the tension of the strip which is unwound from the uncoiler reel and wound onto a coiler. Rolling of metal without creating tension is not possible because in this case the quality of the metal is reduced (appear different thicknesses plots ripple), possible rush band, i.e. the accuracy of maintenance of tension exerts a decisive influence on the course of the process. In order to ensure constancy of tension necessary for coiling strip a linear speed of remains equal to the strip speed at the exit of the mill and the angular speed of the drive motor uncoiler should vary in accordance with the roll diameter [1]. Unwinder works in continuous mode, the total time of acceleration, deceleration, and pause to refuel the new roll is negligibly small compared with the time to work steady speed. Mode of operation of the driving motor decoiler - generative (main technological regime) and motor as an auxiliary mode [1]. When calculating the capacity of the engine electric drive uncoiler [2-4] have to perform quite laborious calculations, since it is necessary to[...]

### The incentive scheme for maintaining or improving power supply quality DOI:10.15199/48.2019.05.20

Czytaj za darmo! »

Modern power systems must supply consumers with the high-quality power with the certain continuity level (that means the term «reliability of power system's work»). There are various aspects of realization of this process (objective and subjective aspects; material, technical, organizational aspects and others). All of them must be analyzed by staff of power distribution companies for improvement of service quality and ways of power supply process perfection must be defined. Employees should use precise and clear algorithm of actions for success of the task performance. They must understand consequences and an ultimate goal. An incentive scheme must be in the power distribution companies for conscientious work of employees. The implantation of an incentive scheme for maintaining or improving general continuity levels was one of recommendations the Council of European Electricity Regulators (CEER) that were submitted in 5-th benchmarking report [1] in 2011 year. The regulation of the service quality in European countries is considered in 6-th CEER benchmarking report on the quality of electricity and gas supply [2]. The systems of regulation are created on the basis of: Continuity measurement is a prerequisite for setting standards and reward/penalty regimes; Maintenance and improvement of general continuity levels as a result of the investment decisions of network operators with implementing reward/penalty for the achieved quality levels; Minimum standards for quality levels will guarantee that consumer will be compensated if the standard is not met by the network operator. The review of use of incentives systems for the distributive companies in the European countries on the basis of key reliability metrics is considered in [2]. Key reliability metrics are indicated in IEEE Std. 1366-1998 Trial-Use Guide for Electric Power Distribution Reliability Indices [3]. These must definitely be interpreted and used as re[...]

### The influence of the specifications of the elements of range of exciters voltage inverters on their spectral characteristics DOI:10.15199/48.2019.05.21

Czytaj za darmo! »

The trend of wide implementation of voltage inverters in various industries is forcing to focus on issues related to electromagnetic compatibility. For example, modern power inverters keys, especially MOSFET and IGВТ with have very high switching speed, become sources of electromagnetic interference. The range of generated interference extends from the carrier frequency of the inverter (several hundreds of KHz) to radio frequency (tens of MHz). Low-frequency interferences up to 2 kHz penetrate into the supply network, high-frequency (> 10 kHz) components create a powerful radio interference [1-4]. It is known that the PLL is generally described by nonlinear differential equations [5]. The non-linear nature of the circuit, which determined by the existence of semiconductor elements (diodes, transistors, thyristors, etc.) which are part of the inverter structure chart, is the reason for generating the higher harmonics. Therefore, we carry out a research on the effects of the non-linear nature of the drivers elements, namely the research of influence of range exciters and inventers systems of phase timing on the spectral characteristics. One of the major problems which must be solved during design and production of the voltage inverter is to eliminate adverse effect of the exciter on the technical characteristics (TС) of the inverter, in particular on electromagnetic compatibility. Thereby, the development of recommendations on the choice the optimal parameter values of the phase-locked loop (PLL) of frequency synthesizer on the basis of accurate numerical analysis occurring therein is very important. For the calculated ratios we use the method of functional expansions of Voltaire, which currently is one of the most convenient and accurate methods for analyzing non-linear dynamic systems [6, 7]. Experiment As the main circuit of direct digital synthesizers (DDS) of range exciters (which basing on the analys[...]

### The field stabilization of optic-active medium of harmful substances sensors

Czytaj za darmo! »

Liquid crystals (LC) can be regarded as a recording medium. Specificity of LC is that they, on the one hand, are an orderly structure, but on the other hand - medium with exceptionally high sensitivity to changes of the regularity under the influence of external factors, what can be easily registered optically due to a large optical anisotropy of the medium. LC output structure can be changed by very weak external factors of different nature: temperature, electric and magnetic fields, radiation of different wavelengths, intermolecular interactions with the substrate and even mechanical or chemical factors that cause changes in optical parameters. Thin films of liquid crystals easily absorb gases and steam from the environment. Gases and steam, absorbed on the surface, significantly alter the optical properties of cholesteric films and, above all, their selective reflection coefficient [1]. Selective properties of cholesteric liquid crystals (CLC) and the ability to change the spiral pitch allow of lasers with tuned frequency. Optical pumping is realized by laser which wavelength falls in the region of dye absorption band. Dye emission wavelength is comparable or equal to cholesteric spiral pith, so a selective light reflection takes place. Therefore cholesteric liquid crystal acts as resonator and selector. The centre wavelength of selective reflection band (SRB) is λmax = nP while the width of the band is Δλ= PΔn, where P is the pitch of the chiral liquid crystal, n = (ne+no)/2 is the average refractive index of the cholesteric planes which have a birefringence of Δn = ne ‑ no, finally ne and no are the extraordinary and ordinary refractive indices respectively [2]. To achieve generation during a pulse laser (solid or gas) excitation into absorpti[...]

### AD systems for processing of low frequency signals based on self calibrate ADC and DAC with weight redundancy DOI:10.15199/48.2017.05.26

Czytaj za darmo! »

Static and dynamic characteristics of modern AD systems of low signals processing are defined by the parameters of ADC and analog devices. Improvement of accuracy and speed of AD systems is possible due to the usage of self-correcting ADC of bitwise balancing ,based on computation n systems with weight redundancy. The ratio between the digit weights in these computation systems is 1 < α < 2. If α = 1.618 "golden ratio" соde is formed. It is shown that increasing of the accuracy and speed of ADC several times is possible due to calibration of static and autocompensation of dynamic balancing errors. Structural block diagrams of the converters for symmetric and asymmetric computation systems are given. The structure of multichannel AD system and method of self-correction of the parameters of input analog devices are developed. Method of calibration and compensation linear distortions of amplitude-frequency and phase-frequency characteristics of measuring channels is shown. The parameters of the developed multichannel AD system for seismic measurements are presented. Streszczenie. Cechy statyczne i dynamiczne nowoczesnych systemów AC do przetwarzania małych sygnałów są definiowane przez parametry przetworników AC i peryferiów analogowych. Poprawa dokładności i szybkości systemów AC jest możliwa dzięki wykorzystaniu samokorygującego przetwornika AC z bilansowaniem bitowym, na podstawie obliczeń n systemów z redundancją wagi. Współczynnik pomiędzy wagami cyfr w tych systemach obliczeniowych wynosi 1 < α < 2. Jeśli α = 1,618 sformułowany zostaje kod "złoty podział". Wykazano, że możliwe jest kilkukrotne zwiększenie dokładności i szybkości przetworników AC dzięki kalibracji statycznej i automatycznej kompensacji błędów dynamicznych. Zaprezentowano schematy blokowe konwerterów dla symetrycznych i asymetrycznych systemach obliczeniowych. Zostały opracowane struktury wielokanałowego systemu AC i sposobu samodzielnego kory[...]

### Analysis of the physical foundations of the build quality of the diagnosis structures based on electronic means of recording and analyzing the parameters of electromagnetic radiation mechanical contact connections DOI:10.15199/48.2017.05.29

Czytaj za darmo! »

The paper presents the results of research that can be put into the development and research of non-contact rapid method for assessing the quality of the assembly and installation of EM designs. To achieve the objectives, studied the behavior of the mechanical connection of the contact pairs, namely the definition of the contribution of R,L,C parameters contact joints in the modulation level and the spectral composition of the electromagnetic radiation mechanical contact pair Streszczenie. W artykule przedstawiono wyniki badań, które mogą być wprowadzane do rozwoju oraz badań bezdotykowego szybkiego sposobu oceny jakości montażu i instalacji projektów EM. W tym celu zbadano zachowanie połączenia mechanicznego pary styków, mianowicie zdefiniowano wpływ parametrów R, L, C połączeń stykowych na poziom modulacji i skład widmowy promieniowania elektromagnetycznego mechanicznego styku par. (Analiza fizycznych podstaw jakości wykonania struktur diagnostycznych opartych na elektronicznym sposobie rejestrowania i analizowania parametrów promieniowania elektromagnetycznego mechanicznych połączeń stykowych) Keywords: diagnostics, mechanical connections, electromagnetic radiation, interference contact Słowa kluczowe: diagnostyka, połączenia mechaniczne, promieniowanie elektromagnetyczne, styk Introduction In today's design and manufacture of electronic means (EM) for assessing the quality of produced mechanical constructions, comprising testing the level of structural strength parameters are used, usually different types of mechanical influences. In this case, removed from the EM signal via mechanical quantities sensors that contain diagnostic information, it is concluded that the technical condition of the structure, the presence of defects. Among the main parameters that characterize the quality of assembly is the presence of non-compliance with tightening torques of threaded connections. This analysis is associated with the processing of larg[...]

### Justification of ice melting capacity on 6-10kV OPL distributing power networks based on fuzzy modeling DOI:10.15199/48.2019.05.26

Czytaj za darmo! »

As it is known [1], the key circuit parameters of ice melting are the value of active power losses per unit of wire length in the mode of melting deposits (melting capacity) and the time of melting deposits, which is a function of the melting capacity. When designing the ice melting schemes with using the special electric power plants of ice melting (limiting reactors, bearish autotransformers [2], iceprotected transformers [3]), which have recently used more often for harmonization of power system with the lines’ parameters. There is a problem of choosing an independent option of melting schemes (the melting capacity of deposits that must be provided by such a facility). The feasibility of mass industrial production of standardized installations for ice melting on 6-10 kV overhead power line (OPL) wires and a variety of parameters of electrical networks 6-10 kV lead to the need to solve this problem, taking into account factors of input data uncertainty. Approaches for designing of ice melting at 6-10 kV OPL electric distribution networks [1, 4] showed that the existing technical and economic models do not allow to take into account the effect of melting deposits power on cost of melting schemes characteristics and make selecting this option. In [5] we developed a single criterion technical and economic model for optimization the parameters of the ice melting schemes at 6-10 OPL using the reduced cost criterion, which takes into account the impact of melting capacity of deposits on such factors of the melting schemes as insufficient outputting of electrical energy to consumers during melting, electric power consumption for melting, the cost of electric power installations for ice melting, the cost of additional capacity of power transformer of the 110-35 / 6- 10 kV district substation. Basing on the model we carried out optimization of power ice melting, which should be provided by different electric power plants wi[...]

### Basis of the necessity of the thermal modelling and analysis of its problem DOI:10.15199/48.2017.05.28

Czytaj za darmo! »

This article describes the main destabilizing factors affecting to the electronic equipment. The basis describes the necessity of the thermal regime in the design of equipment using specialized software. The authors give the example of the calculation of the printed circuit assembly in the subsystem of the thermal modelling “ASONIKA-TM". The authors suggest to pay attention to the main problems of the thermal modelling and the possible ways of its solution. Streszczenie. W artykule opisano główne czynniki destabilizujące, które oddziałują na sprzęt elektroniczny. Opisano konieczność stosowania reżimu termicznego w projektowaniu urządzeń wykorzystujących specjalistyczne oprogramowanie. Autorzy przedstawili przykłady obliczeń zespołu obwodów drukowanych w podsystemie termicznego modelowania “ASONIKA-TM". W publikacji autorzy zwracają uwagę na główne problemy modelowania termicznego oraz możliwe sposoby ich rozwiązania.(Podstawy konieczności modelowania termicznego i analizy tego problemu). Keywords: electronic equipment, modelling, the thermal process, destabilizing factor, printed circuit assembly. Słowa kluczowe: sprzęt elektroniczny, modelowanie, proces termiczny, czynnik destabilizujący, zespół obwodów drukowanych Introduction The modern radio-electrical equipment (REE) of the crucial use (civil or military) works in the conditions of the destabilizing factors, which can be divided into the internal and external factors. The external factors include the influence of the external environment (temperature, humidity, atmospheric pressure), the background of radiation, the electromagnetic fields and mechanical factors. The internal factors include the components of the generated heat based on the electronic components and the activity assembly of the equipment. Unlike the internal, the external destabilizing factors influence to the REE, and even switch off state. Temperature REE consist of the blocks, each of can include [...]

### Substantiation of consolidated inertial parameters of vibrating bunker feeder DOI:10.15199/48.2019.04.09

Czytaj za darmo! »

Vibrating bunker feeders are commonly used to automate production processes. They are widely manufactured by different world enterprises: Spirol International Corporation, Moorfeed Corporation A Division of Executive Automation Systems Inc., NTN Corporation. [1-5]. Two main types of vibration bunker feeders can be distinguished: with directed (fig. 1) and independent (fig. 2) oscillations. In vibration bunker feeders with independent (elliptical) oscillations, the direction of throwing is provided by force disturbance at two independent coordinates. Therefore, for determining the coefficients of stiffness of elastic nodes, we use well-known expressions for the consolidated mass at rectilinear oscillations or the consolidated moment of inertia of the system at angular oscillations [6-10]. a) b) Fig. 1. Vibrating bunker feeders with guided (screw-like) oscillations in which the bowl is made cylinder-like (a) and a conical-like (b) In vibration bunker feeders with propeller oscillations, the direction of throwing is ensured due to sloping elastic elements. In such structures, the propeller movement involves two: rectilinear and angular. Therefore, in order to determine the stiffness coefficient of an elastic node on the basis of a hyperboloid torsion, it is necessary to know the consolidated mass or the summed moment of inertia at propeller-shaped oscillations, which themselves contain, respectively, the proportion of the consolidated moment of inertia of the system at angular oscillations or the consolidated mass in rectilinear oscillations [11,12,16]. Fig. 2. Vibrating bunker feeder with independent (elliptical) oscillations In the technical literature you can find methods for calculating vibration bunker feeders parameters. One of the defining parameters is the consolidated mass or the summed moment of inertia of the oscillatory system, the motion of which is carried out on a propellant trajectory. It is impossible to c[...]

### Determination of oxygen saturation and photosensitizer accumulation in the tumor with the help of LEDand laser diode-based irradiation sources and fiber-optics probes DOI:10.15199/48.2017.05.25

Czytaj za darmo! »

In this paper the possibility of monitoring oxygenation of the tumor tissue through the registration LED technology in photodynamic therapy. The method is applied in the wavelength range, where the spectral difference between oxygenated and deoxygenated hemoglobin is rather high. This method will also help assess the effectiveness of PDT, the level of vascular damage and the degree of the tumor oxygenation. Streszczenie. W artykule przedstawiono możliwość monitorowania stopnia natlenienia tkanki nowotworowej poprzez wykorzystanie źródeł światła LED (light-emitting diodes) w terapii fotodynamicznej (PTD). Metoda może być wykorzystana w takim zakresie długości fal, w którym różnica spektralna pomiędzy hemoglobiną dotlenioną i niedotlenioną jest wysoka. Zaproponowana metoda może być również wykorzystana w ocenie skuteczność terapii PTD, ocenie poziom uszkodzenia naczyń oraz stopienia natlenienia nowotworu. (Wyznaczanie saturacji tlenem oraz akumulacji fotouczulacza w nowotworze przy użyciu sondy światłowodowej oraz źródeł promieniowania wykorzystujących diody LED oraz diody laserowe). Keywords: photodynamic therapy, oxygen saturation, CCD spectrometer, diffuse reflectance spectroscopy, signal fluorescence Słowa kluczowe: terapia fotodynamiczna, nasycenie tlenem, spektrometr CCD, spektroskopia odbicia rozproszonego, sygnał rozproszenia i fluorescencji. 1. Introduction The photodynamic therapy (PDT) procedure involves administration of a photoactive substance - a photosensitizer (PS), which selectively accumulates in malignant tissues, followed by light (laser) irradiation at a wavelength that corresponds to PS absorption characteristics [1, 2]. PS can interact with molecular oxygen, transforming absorbed light energy into singlet oxygen which damages cancer cells due to its strong oxidant activity. Therefore, the effectiveness of PDT treatment depends on molecular oxygen saturation level of irradiated tissues. In clinical settings tumor[...]

« Poprzednia strona  Strona 2  Następna strona »