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  1. 9 Przegląd Elektrotechniczny
  2. 4 Prace Instytutu Mechaniki Górotworu PAN
  3. 4 Transactions of the Strata Mechanics Research Institute
  4. 3 Archives of Electrical Engineering
  5. 3 PAK
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  1. 6 Banaszak S.
  2. 2 Andraș Andrei
  3. 2 Daneshvar Milad
  4. 2 Gawrylczyk K. M.
  5. 2 Jamróz Paweł
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  1. 1 2023
  2. 3 2022
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  5. 8 2019
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1
Content available remote Synthesis of the exact parameters of the electromagnetic brake of a wind electric installation
Aliyev Nadyr, Ahmadov Elbrus Nasi, Khanakhmedova Samira Alkhadi, Rzayeva Sona
Przegląd Elektrotechniczny
|
2023
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R. 99, nr 10
120--124
EN
The article considers the problem of optimal modeling of an electromagnetic brake, as applied to a wind power plant to reduce dangerous fluctuations at high wind speeds and obtain electricity of the required quality. The effectiveness of using the frequency method with the subsequent compilation of equivalent circuits is shown to develop a simplified method for calculating the electromagnetic torque of a brake with a massive magnetic circuit. Taking into account the peculiarities of the study of machines with a massive magnetic circuit, in order to develop an engineering calculation method, the electromagnetic slip clutch (ESC) is considered as an object with lumped parameters. Based on the results of the excitation current damping experiment, an algorithm and a program for solving the problem of synthesizing the parameters of an improved equivalent circuit for an electromagnetic brake with multiloop structures have been developed.
PL
W artykule podjęto problem optymalnego modelowania hamulca elektromagnetycznego zastosowanego w elektrowni wiatrowej w celu zmniejszenia niebezpiecznych wahań przy dużych prędkościach wiatru i uzyskania energii elektrycznej o wymaganej jakości. Wykazano skuteczność zastosowania metody częstotliwości z późniejszym zestawieniem obwodów zastępczych w celu opracowania uproszczonej metody obliczania momentu elektromagnetycznego hamulca z masywnym obwodem magnetycznym. Biorąc pod uwagę specyfikę badania maszyn z masywnym obwodem magnetycznym, w celu opracowania inżynierskiej metody obliczeniowej elektromagnetyczne sprzęgło poślizgowe (ESP) jest uważane za obiekt o parametrach skupionych. Na podstawie wyników eksperymentu tłumienia prądu wzbudzenia opracowano algorytm i program do rozwiązania problemu syntezy parametrów udoskonalonego obwodu zastępczego hamulca elektromagnetycznego o strukturach wielopętlowych.
2
Content available Some problems with the mathematical modeling of electromagnetic vibrators used for transporting bulk materials
Chelidze Merab, Zviadauri Victor, Natriashvili Tamaz
Transport Problems
|
2022
|
T. 17, z. 4
55--65
EN
Mathematical modeling with the original approach is used to study the dynamics of low-frequency electro-vibration machines while taking the technological load into account. Based on the mathematical analysis of differential equations describing the oscillatory motion of electromagnetic vibration exciters, the existing mathematical model has been corrected to describe the action of a semiconductor diode in the power circuits of single-cycle vibrators. Modeling nonlinear dynamic systems reveals the difficulties of obtaining the amplitude frequency characteristics of the associated discrete change in the frequency of the driving force, as well as ways to overcome them.
3
Content available remote Impact of scale factor on performance of miniature DC power source based on wideband vibration energy converter
Kulik Marcin, Górecki Krzysztof, Jagieła Mariusz
Przegląd Elektrotechniczny
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2022
|
R. 98, nr 8
185--188
EN
This paper presents a miniature DC source based on a dual system of nonlinear vibration energy converters along with a converter of an induced voltage. The considered electromagnetic system converts vibrations into electrical energy using internal nonlinearity due to magnetic force dependent on relative position of a moving part. This results in a significant widening of the operating frequency band in comparison to linear system. Based on initial design, the output power and voltage were investigated as functions of the scale factor for the systems with the optimized winding. The result of the study is a construction of a DC power source that generates the output power of minimum of 2 mW (with maximum reaching 8.5 mW) over the frequency range between 15 and 40 Hz, proving the applicability of the system in powering of wireless sensor systems.
PL
W pracy zaprezentowano miniaturowe źródło prądu stałego oparte o układ podwójny nieliniowych przetworników energii drgań wraz z przetwornicą napięcia. Zastosowane elektromagnetyczne układy przetwarzające drgania na energię elektryczną charakteryzują się dodatkową siłą wewnętrzną, co powoduje znaczne poszerzenie pasma częstotliwości pracy w stosunku do układów liniowych. Na podstawie początkowego projektu, przeprowadzono badania mocy oraz napięcia wyjściowego w zależności od współczynnika skalującego, z uwzględnieniem optymalizacji rozłożenia zwojów cewek. W wyniku badań zbudowano źródło prądu stałego generujące minimum 2 mW (max 8.5 mW) w zakresie częstotliwości od 15 do 40 Hz, co dowodzi możliwości zastosowania w zasilaniu bezprzewodowych systemów pomiarowych.
4
Content available The magnitude optimum design of the PI controller for plants with complex roots and dead time
Cvejn Jan
Archives of Control Sciences
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2022
|
Vol. 32, No. 1
5--35
EN
Analytical design of the PID-type controllers for linear plants based on the magnitude optimum criterion usually results in very good control quality and can be applied directly for high-order linear models with dead time, without need of any model reduction. This paper brings an analysis of properties of this tuning method in the case of the PI controller, which shows that it guarantees closed-loop stability and a large stability margin for stable linear plants without zeros, although there are limitations in the case of oscillating plants. In spite of the fact that the magnitude optimum criterion prescribes the closed-loop response only for low frequencies and the stability margin requirements are not explicitly included in the design objective, it reveals that proper open-loop behavior in the middle and high frequency ranges, decisive for the closed-loop stability and robustness, is ensured automatically for the considered class of linear systems if all damping ratios corresponding to poles of the plant transfer function without the dead-time term are sufficiently high.
5
Content available remote Diagnostics of turbine blades, based on estimation of frequency response function
Kotkowski Jerzy, Rokicki Edward, Lindstedt Paweł, Spychała Jarosław, Perczyński Jerzy, Karbowiak Hieronim
Journal of KONBiN
|
2021
|
Vol. 51, iss. 2
63--78
EN
The aim of the study is to propose a diagnostics method based on blade’s vibration model in frequency domain. Amplitude spectrum A(ω) and phase spectrum φ(ω) have been experimentally identified which define transfer function G(jω) = P(ω) + jQ(ω) and their real P(ω) and imaginary Q(ω) parts. Transfer function G(jω) and resulting frequency, amplitude, phase characteristics and real P(ω) and imaginary Q(ω) parts are parts of blade’s diagnostics model. Changes in those characteristics are directly related to changes in the technical condition of the blades. It has been noticed that small changes in the technical condition cause large changes in frequency characteristics, which proves their usefulness in the diagnosis process.
PL
Celem badania jest zaproponowanie metody diagnostycznej opartej na modelu drgań łopatek w dziedzinie częstotliwości. Zidentyfikowano eksperymentalnie widma ampli-tudowe A(ω) i fazowe φ(ω), które definiują transmitancję operatorową G(jω) = P(ω) + jQ(ω) oraz jej rzeczywiste P(ω) oraz urojone Q(ω) części. Transmitancja operatorowa G(jω) i wynikająca z niej częstotliwość, amplituda, charakterystyka fazowa oraz rzeczywiste P(ω) i urojone Q(ω) części są częściami modelu diagnostycznego łopatki. Zmiany w tych charakterystykach są bezpośrednio związane ze zmianami w stanie technicznym łopatek. Zauważono, że małe zmiany w stanie technicznym powodują duże zmiany w charakterystykach częstotliwościowych, co świadczy o ich przydatności w procesie diagnostycznym.
6
Content available Effect Analysis of Loudspeaker’s Placement Angle and Direction on Frequency Response and Sound Pressure Level in TV Applications
Demirel Ibrahim
Archives of Acoustics
|
2021
|
Vol. 46, No. 1
79--85
EN
In a television, obtaining a good acoustic response is a challenging issue because of slim mechanical structures. The area dedicated for speaker’s placement is limited and inadequate space inside the cabinet of a TV prevents possible solutions to increase the sound performance. In addition, frame of the TV’s is getting narrower as the customers searching for the highest screen to body ratio. These designing aspects restrain optimal speaker positioning to achieve good sound performance. In this paper, an analysis related to speaker’s placement and mounting angle is proposed. A rotation setup compatible with a TV was prepared to measure different facing position of the speaker. This paper proposes the analysis of speaker’s rotation and facing direction in a flat panel television and its effects on sound pressure level together with deviation of the acoustic response. Measurement results are analyzed with an audio analyzer together with a statistics tool to achieve precise results.
7
Content available remote Modyfikacja mostkowego układu anemometru stałotemperaturowego do badań w szerokim zakresie fluktuacji prędkości przepływów
Ligęza Paweł, Jamróz Paweł, Ostrogórski Piotr
Prace Instytutu Mechaniki Górotworu PAN
|
2020
|
T. 22, nr 1-4
3--7
PL
Stosowana w badaniu przepływów turbulentnych metoda termoanemometryczna polega na pomiarze wielkości fizycznych opisujących przepływ poprzez pomiar strat cieplnych miniaturowego nagrzanego elementu. Termoanemometr umożliwia pomiary przepływów szybkozmiennych w szerokim zakresie prędkości, przy dobrym stosunku sygnału do szumu. Pasmo przenoszenia sięga setek kiloherców, a zakres mierzonych prędkości od ułamków metra na sekundę do prędkości ponaddźwiękowych. W artykule przedstawiono koncepcję modyfikacji klasycznego mostkowego układu anemometru stałotemperaturowego z przeznaczeniem do badań w szerokim zakresie fluktuacji prędkości przepływu. Istotą zaproponowanej modyfikacji jest przede wszystkim ograniczenie szumów własnych układu przy zachowaniu bardzo dobrych parametrów dynamicznych. Układ przeznaczony jest do badań przepływów turbulentnych o szerokim spektrum częstotliwościowym fluktuacji prędkości.
EN
The hot-wire anemometric method used in the study of turbulent flows consists in measuring the physical quantities describing the flow by measuring thermal losses of a miniature heated element. The hot-wire anemometer enables measurements of fast-varying flows over a wide velocity range, with a good signal-to-noise ratio. The frequency response is of hundreds of kilohertz, and the measured velocity ranges is from centimeters per second to supersonic speeds. The article presents the concept of modification of the classic bridge of constant-temperature anemometer system intended for testing in a wide spectral range of flow velocity fluctuations. The essence of the proposed modification is, above all, to reduce the system’s own noise while maintaining very good dynamic parameters. The system is designed to study turbulent flows with a wide frequency spectrum of velocity fluctuations.
8
Content available Frequency Response Testing of Zero-Sequence Current Transformers for Mining Ground Fault Protection Relays
Kuliński Krzysztof, Heyduk Adam
International Journal of Electronics and Telecommunications
|
2020
|
Vol. 66, No. 4
701--705
EN
In Polish coal mining, medium voltage power distribution networks operate with an insulated neutral point. Zero-sequence current transformers are the basic sensors that generate input signals for earth-fault protection relays. In the literature, the problem of frequency response analysis of various types of current transformers has been examined many times, e.g. [1] [2], but not for zero-sequence current transformers so far. As part of the work, two types of zero-sequence current transformers in the range from 0.1 Hz to 100 kHz were tested. Both the change of the current ratio and the angular shift between the transformer secondary current and the total primary current were analyzed.
9
Content available Multi-channel digital-analog system based on current-current converters
Azarov Olexiy, Heneralnytskyi Yevhenii, Rybko Nataliia
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
|
2020
|
T. 10, nr 4
43--46
EN
An approach to building a multi-channel digital-analog system is proposed, in which, unlike the known ones, a code-current converter, a controlled current generator, and also a current communication block are used. For a given accuracy, this saves on the analog system equipment. It has been shown that the proposed principle of building a controlled current source in the form of a highly linear push-pull amplifier – current scalar on bipolar transistors with a grounded load – has a high output resistance and wide bandwidth, which allows the use of current switching to implement the multi-channel system mode.
PL
Proponowane jest podejście do budowy wielokanałowego systemu cyfrowo - analogowego, w którym w odróżnieniu od znanego jednego przetwornika oferowany jest kod - prąd, generator prądu sterowanego, a także blok komunikacji prądów. Pozwala to zaoszczędzić na danej dokładności na sprzęcie analogowym systemu. Wykazano, że proponowana zasada budowy sterowanego generatora prądu w postaci wysoce liniowego wzmacniacza dwutaktowego – skaler prądu na tranzystorach bipolarnych z uziemionym obciążeniem ma wysoką rezystancję wyjściową i szerokie pasmo, co pozwala na zastosowanie przełączania prądu do realizacji trybu systemu wielokanałowego.
10
Content available Frequency response analysis of microcontroller-based discrete-time lead-lag compensators
Dewantoro Gunawan, Rizky Irwin Shauma, Murtianta Budihardja
Archives of Electrical Engineering
|
2020
|
Vol. 69, nr 4
937--950
EN
With the rapid advancement of digital processors, filters have been commonly implemented using microcomputers. In this study, a low-cost and compact Arduino Uno development board was used to realize digital lead and lag compensators. Arduino boards are very affordable. Consequently, they were investigated to see if they were capable of preserving the frequency response of continuous-time compensators. The experiments required a set of equipment including a function generator, an Arduino Uno development board, a PC-based oscilloscope, and a laptop. The signal frequency was varied from 0 to 500 Hz. Two discretization methods were employed, namely bilinear transformation and matched pole-zero mapping. The results showed that an Arduino Uno board can be utilized to implement lead and lag compensators to some extent. The discrete-time compensator preserved the capability of filtering out certain frequencies. The change in DC gain was negligible, however, there was a significant difference in the cut-off frequency and transient slope. For both discretization methods, the frequency responses at high frequency experienced a rippling profile.
11
Content available A new method to reduce electromagnetic interference using signal modeling
Daneshvar Milad, Parhizgar Nasser, Oraizi Homayoon
Archives of Electrical Engineering
|
2020
|
Vol. 69, nr 4
829--840
EN
Controlling and reducing the radiation emitted by various systems helps the board designer improve systems’ performance. One proposed way to achieve these goals is to use an algorithm to control the radiation applied to systems. According to the executive structure of the algorithm and considering the nature of the existing signals in several components, the separation of the signal components is on the agenda of the algorithm. In fact, the goal is to create an intuitive view of the multi-component signals around the systems that enter the systems from different angles and have a detrimental effect on their performance. Using signal processing methods, we will be able to break down the signal into different components and simulate each component separately. To prevent high computational repetitions and increase simulation time in signal component analysis, by reducing the components, we reduce the number of mesh cells in the software and, using linear approximation, determine the exact position of the radiation signal applied to systems and thus the best linear relationship. The signal entry path is used to apply the rules required for prediction design.
12
Content available remote Metoda eliminacji zakłóceń elektromagnetycznych w pomiarach termoanemometrycznych
Ligęza Paweł, Jamróz Paweł, Ostrogórski Piotr, Poleszczyk Elżbieta
Prace Instytutu Mechaniki Górotworu PAN
|
2019
|
T. 21, nr 1-4
33--38
PL
Podstawowy obszar aplikacyjny termoanemometrów stanowią pomiary fluktuacji prędkości przepływu gazów w szerokim spektrum częstotliwości. Istotną cechą termoanemometrycznych systemów pomiarowych jest więc możliwie duże pasmo przenoszenia sygnału pomiarowego. Standardowo szerokie pasmo przenoszenia uzyskuje się poprzez zastosowanie stałotemperaturowego trybu pracy anemometru. W trybie tym temperatura grzanego elementu pomiarowego utrzymywana jest na stałym poziomie dzięki zastosowaniu układu elektronicznego ze sprzężeniem zwrotnym. Pasmo przenoszenia dla termoanemometrów stałotemperaturowych może sięgać setek kiloherców. Ponieważ czujnik termoanemometryczny stanowi pod względem elektrycznym rodzaj pętli indukcyjnej, mogą indukować się w nim zakłócenia elektromagnetyczne. Duże wzmocnienie oraz szerokie pasmo przenoszenia układu stałotemperaturowego powodują, że w przypadku występowania zakłóceń elektromagnetycznych udział sygnałów niepożądanych w sygnale wyjściowym termoanemometru może być znaczący. W pracy tej przedstawiono koncepcję metody eliminacji tych zakłóceń.
EN
The main application area for hot-wire anemometers are measurements of gas flow velocity fluctuations in a wide range frequency spectrum. An important feature of hot-wire anemometric measuring systems is therefore the highest possible frequency bandwidth of the measuring circuit. As a standard, a wide frequency response is obtained by using a constant temperature mode of the anemometer. In this mode, the temperature of the heated measuring element is kept constant, by the use of an electronic system with feedback. The frequency response for constant temperature anemometers can reach hundreds of kilohertz. Since the hot-wire sensor is a kind of induction loop in electrical terms, electromagnetic interference may be induced in it. The high gain and the wide frequency bandwidth of the constant temperature system mean that in the event of electromagnetic interference, the share of unwanted signals in the output signal of the anemometer can be significant. This work presents the concept of the method for eliminating these disturbances.
13
Content available Vibration analysis of a bucket wheel excavator boom using rayleigh’s damping model
Popescu Florin Dumitru, Radu Sorin Mihai, Kotwica Krzysztof, Andraș Andrei, Kertesz (Brînaș) Ildiko, Dinescu Stela
New Trends in Production Engineering
|
2019
|
Vol. 2, Iss. 1
233--241
EN
For the ERc 1400-30/7 type bucket wheel excavator (BWE) used in various Romanian open pit mines, a virtual model of the boom was constructed in SolidWorks. On this model, the variable in time forces acting during the excavation process were simulated, and the time history analysis (time response) was performed. This dynamic time response analysis was performed for excavation of homogenous material only, considering the damping as being of Rayleigh’s type, where the damping matrix is a linear combination of the mass and stiffness matrices. Based on the conducted analysis, the displacements of the boom during excavation were observed.
14
Content available Simulation of the frequency response of the ERC 1400 Bucket Wheel Excavator boom, during the excavation process
Popescu Florin Dumitru, Radu Sorin Mihai, Andraș Andrei, Kertesz (Brînaș) Ildiko
New Trends in Production Engineering
|
2019
|
Vol. 2, Iss. 1
153--167
EN
The paper deals with the modal analysis and frequency response analysis of a bucket wheel excavator (BWE) boom, obtained by simulation, based on a virtual model of an existing BWE boom. The boom, which generally is realized as a spatial truss, is the most vulnerable subsystem of the BWE, being submitted to severe operational loads characterized by very pronounced cyclical, dynamic and stochastic variability. This vulnerability is the consequence of its shape and constructive parameters and the nature, source and character of the external exciting loads to which it is exposed. The classical approach recommended by standards and norms cannot predict the occurrence of failures caused by vibration, which produces fatigue due to the load’s cyclical variability and the deformation produced by resonant vibration of some constitutive elements. As exciting load we considered the operational forces acting on the bucket wheel. In this manner we can take into account the constructive features - with modal analysis, and the vibration regime - with frequency response analysis. The proposed method is useful both in the design phase of new load-bearing structures of truss type subjected to high-variability forces, and also in refurbishment or improvement phases of the existing structures of this kind.
15
Content available Wybrane aspekty mechaniczne samochodu napędzanego silnikami elektrycznymi wbudowanymi w piastach kół
Dukalski Piotr, Będkowski Bartłomiej, Parczewski Krzysztof, Wnęk Henryk, Urbaś Andrzej, Augustynek Krzysztof
Maszyny Elektryczne : zeszyty problemowe
|
2019
|
Nr 2 (122)
173--178
PL
W artykule przedstawiono dynamikę układu tylnego zawieszenia samochodu Fiata Panda III z silnikami elektrycznymi wbudowanymi w koła. Przedstawione w niniejszym artykule wyniki analizy dynamiki są kontynuacją prac autorów nad wpływem mas nieresorowanych (w postaci silników elektrycznych wbudowanych w piastach kół), na zachowanie się układu tylnego zawieszenia, a rezultacie całego pojazdu w różnych warunkach drogowych. Analizy przeprowadzono stosując metody dynamiki układów wieloczłonowych (UW) zaimplementowane w oprogramowaniu MSC.Adams. We wcześniejszych pracach dokonano walidacji modelu symulacyjnego, poprzez porównanie wyników numerycznych z testami drogowymi, otrzymując w rezultacie zweryfikowany model numeryczny z poprawnie dobranymi parametrami fizycznymi. W niniejszej pracy skupiono się na analizie wpływu średnich i dużych prędkości przejazdu ( υ={30,60,120}km/h ) przez nierówność w postaci prostokątnej wypukłości oraz wgłębienia w jezdni o tych samych wymiarach na przyspieszenia środków kół bez silników oraz z silnikami elektrycznymi wbudowanymi w piastach kół. Przyspieszenia analizowano w dziedzinie czasu oraz w dziedzinie częstotliwości.
EN
The dynamics of the Fiat Panda III rear suspension system with electric motors built into the wheel hubs is presented in the paper. The results of the dynamics analysis presented in the article are a continuation of the authors' work on the impact of unsprung masses (here in the form of electric motors mounted in the wheel hubs) on the behavior of the rear suspension system and entire vehicle in various road conditions. The analyzes were carried out using multibody dynamics methods implemented in the MSC.Adams software. In previous works, the simulation model was validated by comparison numerical results with road tests, resulting in a verified numerical model with correctly selected physical parameters. This paper focuses on the analysis of the impact of the medium and high speed of passing over an obstacle ( υ ={30,60,120}km/h ) in the form of a rectangular bump and hole on the accelerations of wheel centers without motors and with electric motors embedded in the wheel hubs. Accelerations of the wheel centers are analyzed in the time and frequency domain.
16
Content available Frequency response based curve fitting approximation of fractional-order PID controllers
Bingi Kishore, Ibrahim Rosdiazli, Karsiti Mohd Noh, Hassam Sabo Miya, Harindran Vivekananda Rajah
International Journal of Applied Mathematics and Computer Science
|
2019
|
Vol. 29, no. 2
311--326
EN
Fractional-order PID (FOPID) controllers have been used extensively in many control applications to achieve robust control performance. To implement these controllers, curve fitting approximation techniques are widely employed to obtain integer-order approximation of FOPID. The most popular and widely used approximation techniques include the Oustaloup, Matsuda and Cheraff approaches. However, these methods are unable to achieve the best approximation due to the limitation in the desired frequency range. Thus, this paper proposes a simple curve fitting based integer-order approximation method for a fractional-order integrator/differentiator using frequency response. The advantage of this technique is that it is simple and can fit the entire desired frequency range. Simulation results in the frequency domain show that the proposed approach produces better parameter approximation for the desired frequency range compared with the Oustaloup, refined Oustaloup and Matsuda techniques. Furthermore, time domain and stability analyses also validate the frequency domain results.
17
Content available remote Performance evaluation and frequency response analysis of a two stage two spool electrohydraulic servovalve with a linearized model
Mondal Nitesh, Datta Biswanath
Engineering Transactions
|
2019
|
Vol. 67, iss. 3
411--427
EN
This article focuses on the performance study and frequency response analysis with the state space model of a linearized two stage two spool non-conventional electrohydraulic servovalve from a set of nonlinear state equations. The performance of this valve depends on many valve geometries and fluid parameters. This non-conventional electrohydraulic servovalve is controlled by a pressure controlled pilot, which generates a differential pressure between the upper and lower chambers of two spools. This differential pressure acts as the feedback element, thereby reducing the requirement for a feedback wire. In this paper, the dynamic behaviour and state-space model of the valve is established with the aid of linearized mathematical equations and the coefficients of the equations directly depend on the valves parameters, fluid properties and flow properties. The dynamic performance of this valve and the frequency response are analysed with the help of MATLAB/Simulink.
18
Content available The effect of fuel mixture on engine vibrations
Wróbel Radosław, Łoza Łukasz, Haller Piotr, Włostowski Radosław
Combustion Engines
|
2019
|
R. 58, nr 2
136--138
EN
In the article, the authors analyze the effect of a fuel mixture (iso-octane, butanol and ethanol) on the generation of engine vibrations. The paper presents the results in the form of frequency response (using the Fast Fourier Transform - FFT) for three mixtures of different proportions. The measurements were made with the use of accelerometers and data acquisition cards, conditioning the received signal. The vibration component, in the form of acceleration, will be subjected to a FFT and presented in graphical form (periodogram). The authors put a special emphasis on a comparative analysis, indicating changes in harmonics, which may be a potential cause of engine degradation.
19
Content available A novel method for separability of signal components to estimate radiation from a high-frequency subsystem
Daneshvar Milad, Parhizgar Naser, Oraizi Homayoon
Archives of Electrical Engineering
|
2019
|
Vol. 68, nr 3
497--510
EN
Specific requirements are designed and implemented in electronic and telecommunication systems for received signals, especially high-frequency ones, to examine and control the signal radiation. However, as a serious drawback, no special requirements are considered for the transmitted signals from a subsystem. Different industries have always been struggling with electromagnetic interferences affecting their electronic and telecommunication systems and imposing significant costs. It is thus necessary to specifically investigate this problem as every device is continuously exposed to interferences. Signal processing allows for the decomposition of a signal to its different components to simulate each component. Radiation control has its specific complexities in systems, requiring necessary measures from the very beginning of the design. This study attempted to determine the highest radiation from a subsystem by estimating the radiation fields. The study goal was to investigate the level of radiations received and transmitted from the adjacent systems, respectively, and present methods for control and eliminate the existing radiations. The proposed approach employs an algorithm which is based on multi-component signals, defect, and the radiation shield used in the subsystem. The algorithm flowchart focuses on the separation and of signal components and electromagnetic interference reduction. In this algorithm, the detection process is carried out at the bounds of each component, after which the separation process is performed in the vicinity of the different bounds. The proposed method works based on the Fourier transform of impulse functions for signal components decomposition that was employed to develop an algorithm for separation of the components of the signals input to the subsystem.
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Content available remote Digital filters to separate the first and second harmonics of signals in microprocessor-bases protection of electrical installations equipped with transformers
Romanyuk F., Kachenya V., Kierczyński K.
Przegląd Elektrotechniczny
|
2018
|
R. 94, nr 7
46--49
EN
The shortcomings of the sine and cosine digital filters used in microprocessor-based protection of electrical installations are discussed in the article; a technique to overcome the shortcomings is proposed. The mathematical description of non-recursive filters is presented. One of the models of the proposed method of formation of the orthogonal components is presented as well. The study of frequency and transient responses of digital filters at different types of input impact was performed. The reaction of various filters to inrush of magnetization currents of power transformers is investigated.
PL
W artykule omówiono wady cyfrowych filtrów sinusoidalnych i cosinusoidalnych stosowanych w mikroprocesorowej ochronie instalacji elektrycznych, zaproponowano technikę poprawy tych wad. Przedstawiono matematyczny opis filtrów nierekurencyjnych. Omówiono również jeden z modeli proponowanej metody tworzenia składowych ortogonalnych. Przeprowadzono badania częstotliwości i odpowiedzi filtrów cyfrowych przy różnych typach sygnału wejściowego. Zbadano reakcję różnych filtrów na oddziaływanie prądów magnesujących transformatorów mocy.
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