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Tytuł:
Continuous Head-related Transfer Function Representation Based on Hyperspherical Harmonics
Autorzy:
Szwajcowski, Adam
Powiązania:
https://bibliotekanauki.pl/articles/31339927.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
hyperspherical harmonics
HRTF
spherical harmonics
continuous functional model
directivity
Opis:
Expressing head-related transfer functions (HRTFs) in the spherical harmonic (SH) domain has been thoroughly studied as a method of obtaining continuity over space. However, HRTFs are functions not only of direction but also of frequency. This paper presents an extension of the SH-based method, utilizing hyperspherical harmonics (HSHs) to obtain an HRTF representation that is continuous over both space and frequency. The application of the HSH approximation results in a relatively small set of coefficients which can be decoded into HRTF values at any direction and frequency. The paper discusses results obtained by applying the method to magnitude spectra extracted from exemplary HRTF measurements. The HRTF representations based on SHs and HSHs exhibit similar reproduction accuracy, with the latter one featuring continuity over both space and frequency and requiring much lower number of coefficients. The developed HSH-based continuous functional model can serve multiple purposes, such as interpolation, compression or parametrization for machine-learning applications.
Źródło:
Archives of Acoustics; 2023, 48, 1; 127-139
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fast four-point estimators of sinusoidal signal parameters – numerical optimisations for embedded measuring systems
Autorzy:
Zygarlicki, Jarosław
Zygarlicka, Małgorzata
Mroczka, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/221511.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
signal processing
harmonics
measurements
Opis:
The paper presents an algorithm for determining parameters of single sinusoidal components contained in the analyzed digital signal with the use of a small number of mathematical operations. The proposed algorithm can be applied, among others, in measuring devices to monitor basic parameters of electric energy quality as well as in devices used to determine the phasor in the power system. The proposed simplification of the algorithm for determining the sinusoidal components of the analyzed signal allows to use it in embedded devices with low computing power, which translates into lower cost of construction of devices of this type, while maintaining full functionality of the measuring system. The article contains a mathematical argument, which leads to the proposed algorithm, then the optimization of the number of performed mathematical operations is presented. The last part of the paper includes information about performed mathematical operations and presents exemplary times of execution of the algorithm for simple embedded devices.
Źródło:
Metrology and Measurement Systems; 2020, 27, 3; 465-472
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Case of Hidden Instantaneous Powers
Autorzy:
Balci, M. E.
Emanuel, A. E.
Powiązania:
https://bibliotekanauki.pl/articles/262606.pdf
Data publikacji:
2008
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
harmonics
power definitions
power factor
Opis:
This brief communication addresses the case of a dc nonlinear load supplied with a perfectly constant instantaneous power. A careful analysis shows that this condition does not provide optimum transfer of electric energy .
Źródło:
Electrical Power Quality and Utilisation. Journal; 2008, 14, 2; 3-5
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An optimum reactance one-port compensator for harmonic mitigation
Autorzy:
El-Saadany, E. F.
Zeineldin, H.
Powiązania:
https://bibliotekanauki.pl/articles/262641.pdf
Data publikacji:
2005
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
filter
harmonics
nonlinear loads
optimization
Opis:
The installation of electronic devices, digital equipment, and nonlinear loads in both industrial and domestic applications have dramatically increased in recent years, which in turn increased the level of harmonics in the system. Harmonic distortion is widely recognized as a significant cause of damage to, and mat-operation of electrical equipment. A harmonic filter can eliminate the potentially dangerous effects of harmonic currents created by nonlinear loads. There are two types of harmonic filters: passive filters and active filters. Passive filters are inexpensive compared with most mitigating devices. In this paper, reactance one-port compensator is designed for current harmonic mitigation. The optimal parameters the filter are determined using the Branch and Reduce Optimization Navigator (BARON) Nonlinear Programming Solver in the General Algebraic Modeling System (GAMS).
Źródło:
Electrical Power Quality and Utilisation. Journal; 2005, 11, 1; 77-82
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New Control Algorithms for Three-Phase Four-Wire Unified Power Quality Conditioner - a simulation study
Autorzy:
Pal, Y.
Swarup, A.
Singh, B.
Powiązania:
https://bibliotekanauki.pl/articles/262781.pdf
Data publikacji:
2013
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
UPQC
power quality improvement
source neutral current
mitigation
load balancing
voltage harmonics
current harmonics
Opis:
In this paper, some new control algorithms are proposed for a three-phase four-wire Unified Power Quality Conditioner. These control algorithms are based on the combination of Unit Vector Template Generation (UVTG) with Power Balance Theory (PBT), single phase d-q theory, Synchronous Current Detection (CSD) technique, and I CosΦ theory. The performance of each control algorithm of UPQC is evaluated in terms of power factor correction, load balancing and source neutral current mitigation, and voltage and current harmonic mitigation. The performance of proposed control algorithms are compared with synchronous reference frame (SRF) based control algorithm. In each proposed control scheme of the three-phase four-wire UPQC, the current/voltage control is applied over the fundamental supply currents/ load voltages instead of fast changing APFs currents/ voltages, thereby reducing the effects of computational delay. Moreover, the load neutral or shunt APF neutral currents are not sensed hence the required current sensors are reduced. MATLAB/ Simulink based simulations are obtained, which support the functionality of the UPQC.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2013, 16, 1; 1-10
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of disturbing effect of 3 kV DC supplied traction vehicles equipped with two-level and three-level VSI on railway signalling track circuits
Autorzy:
Steczek, M.
Szeląg, A.
Chatterjee, D.
Powiązania:
https://bibliotekanauki.pl/articles/201149.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
voltage source inverters
traction vehicle
compatibility
harmonics
harmonics elimination
źródła napięcia
pojazd trakcyjny
zgodność
harmonia
Opis:
Electric traction vehicles cooperating with a 3kV DC traction system and equipped with drive systems based on voltage source inverters are the most significant sources of disturbances for a railway signalling system. Every traction vehicle to be authorised for operation on railway lines must fulfil the limits imposed on current harmonics magnitudes and those provided by railway operators. The solution introduced for prototypes of most modern traction drives is to replace the two-level inverters with three-level topology. Therefore, it is essential to establish the influence of the new solution on the railway signalling system. This paper presents a comparative analysis between simulation results delivered for two and three-level traction drive system regarding generation of disturbing current harmonics. Two types of VSI modulation techniques were taken under consideration: sinusoidal PWM (SPWM) and a new one, proposed by the authors, based on selective harmonic elimination (SHE). Furthermore, the authors presented application of one of the SHE based optimization techniques for shaping the EMU’s (electric multiple unit) DC side input current harmonics spectrum in order to meet the required limits. The described technique is based on off-line generation of a set of solutions for each of the VSI operating points and selection of the best solution for the assumed criteria. The applied simulation models and the concept of SHE control were verified in a laboratory by means of a low-power drive stand. Using the three-level inverter in traction drives system results in less current harmonics than using two-level topology without modification of the modulation technique. Thus, it does not guarantee fulfilling all limits assumed in this paper. The proposed modulation technique allows for fulfilling the limits, and the technical implementation of the proposed technique in a traction drive system will be considered in future studies.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2017, 65, 5; 663-674
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of harmonics reduction methods selection for transformer substation
Autorzy:
Racewicz, Szymon
Rokicki, Mateusz
Powiązania:
https://bibliotekanauki.pl/articles/298173.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
harmonics reduction
active filters
THD coefficient
Opis:
The article presents an investigation of the harmonic level and its possible reduction methods for one of the Michelin factory transformer substation. The substation electrical network consists of two transformers (1.6 MVA and 2.0 MVA) supplying a production line composed of several electrical equipment based on DC and AC motors. In order to investigate the harmonics level and its influence on the substation operation the measurements of the current and the load factor of the powered machines as well as the coefficients THDu, THDi, Du and Di have been performed using the 3-phase energy quality analyzer Fluke 435II and the network parameter recorder PEL103. Basing on the measurements data the four harmonics reduction methods (passive filters, active filters, 12-pulse rectifier and the Active Front End system) have been proposed and studied. For this purpose the substation electrical network has been modelled using Emerson Harmonics Estymator software. Furthermore, in order to choose the optimal solution the financial analysis of the potential investments has been performed.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2020, 23(1); 5-23
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reconditioning in synchronous operation with one parallel induction generator
Autorzy:
Magalhães, A. S.
Moraes, P. H. F.
Silva, A. H. F.
Gomes, P. H. G.
Alves, A. J.
Calixto, W. P.
Powiązania:
https://bibliotekanauki.pl/articles/136216.pdf
Data publikacji:
2016
Wydawca:
EEEIC International Barbara Leonowicz Szabłowska
Tematy:
repowering
induction generator
synchronous generator
harmonics
Opis:
The purpose of this paper is to compare mathematical modeling and practical bench in order to validate the electrical interactions between an induction generator and a synchronous generator. Two generators was connected to a common bus in steady state, subject to non-linear load. The results comparing modeling and bench tests show that the induction generator besides the active power increasing, has a better way for harmonic currents flowing in common bus. It was concluded that the induction generator repowering and attenuates current harmonic components present at the connection point, improving the network voltage profile.
Źródło:
Transactions on Environment and Electrical Engineering; 2016, 1, 4; 66-72
2450-5730
Pojawia się w:
Transactions on Environment and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Long-Term Monitoring of Flicker and Some Other Parameters of Voltage Quality
Autorzy:
Krejci, P.
Santarius, P.
Gono, R.
Brunclik, Z.
Powiązania:
https://bibliotekanauki.pl/articles/136258.pdf
Data publikacji:
2016
Wydawca:
EEEIC International Barbara Leonowicz Szabłowska
Tematy:
flicker
unbalance
voltage harmonics
voltage quality
Opis:
In 1997 cooperation began between the Faculty of Electrical Engineering and Computer Science and the power company CEZ on a joint project that involved monitoring selected voltage quality parameters. Over the course of several years measurements were carried out at 59 points of the distribution system at a low voltage (LV) level and their power supply nodes at medium voltage (MV) and high voltage (HV) levels, which constituted more than 100 measured points. The measurements continued until 2012 (with a one-year break in 2009) and with a total scope of five cycles of three-year measurements. The last phase of the measurements was focused, inter alia, on the evaluation of 15th and 21st voltage harmonics. From 2013, the cooperation focused again on monitoring flicker in localities with the occurrence of elevated levels of this voltage quality parameter. At these sites, the monitoring of flicker was carried out for two weeks in spring and autumn for a period of three years. The basis for evaluating the quality parameters is the standard EN 50160. In addition the results of annual continual monitoring for one selected locality on MV level will be presented in the paper. In addition the possibility of utilization of intelligent electrometers for monitoring of some quality parameters will be referred in the paper.
Źródło:
Transactions on Environment and Electrical Engineering; 2016, 1, 3; 1-8
2450-5730
Pojawia się w:
Transactions on Environment and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variable-frequency Prony method in the analysis of electrical power quality
Autorzy:
Zygarlicki, J.
Mroczka, J.
Powiązania:
https://bibliotekanauki.pl/articles/221630.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power quality
Prony method
harmonics
measurements
Opis:
The article presents a new modification of the the least squares Prony method. The so-called variable-frequency Prony method can be a useful tool for estimating parameters of sinusoidal components, which, in the analyzed signal, are characterized by time-dependent frequencies. The authors propose use of the presented method for testing the quality of electric energy. It allows observation of phenomena which, when using traditional methods, are averaged in the analysis window. The proposed modification of least squares Prony method is based on introduction and specific selection of a frequency matrix. This matrix represents frequencies of estimated components and their variability in time.
Źródło:
Metrology and Measurement Systems; 2012, 19, 1; 39-48
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Method of testing and correcting signal amplifiers transfer function using Prony analysis
Autorzy:
Zygarlicki, J.
Mroczka, J.
Powiązania:
https://bibliotekanauki.pl/articles/221749.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Prony method
signal processing
harmonics
measurements
Opis:
This article presents a way of analyzing the transfer function of electronic signal amplifiers. It also describes the possibility of using signal precorrection which improves the parasitic harmonics in the THD (Total Harmonic Distortion) of the amplified signal by correcting linearity of the tested amplifier?s transfer function. The proposed method of analyzing and presenting the transfer function allows to diagnose the causes of generating parasitic harmonics, what makes it a useful tool when designing low distortion amplifier systems, such as e.g. amplifiers in measurement systems. The presented THD correction can be used in e.g. amplifier systems that cooperate with arbitrary generators.
Źródło:
Metrology and Measurement Systems; 2012, 19, 3; 489-498
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pronys method used for testing harmonics and interharmonros in electrical power systems
Autorzy:
Zygarlicki, J.
Mroczka, J.
Powiązania:
https://bibliotekanauki.pl/articles/221178.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Prony's method
signal processing
harmonics
measurements
Opis:
The article presents an application of Prony's method with some known components in the analysis of electric power quality. Modifications of the Prony algorithm broaden the scope of method application. Modification of the filter of known components enables more accurate analysis of the parameters of unknown components and components with known or assumed frequencies. This article presents a comparison of the results of analyses conducted with the proposed algorithm for simulated and real signals and the results obtained by means of a commercial electric power quality testing device, operating in class A and using the Fourier transform. The proposed method enables to estimate the levels of the harmonic components, the frequency of the fundamental signal and real parameters of the interharmonic components, which are grouped and averaged in the contemporary monitoring equipment. Knowledge of the individual parameters of the interharmonics has considerable diagnostic importance while removing causes of incorrect operation affecting sensitive equipment in some electric power systems. Additionally, the algorithm is capable of analyzing exponentially damped components and finds its application in analysis of disturbances, for example, transient oscillations.
Źródło:
Metrology and Measurement Systems; 2012, 19, 4; 659-672
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Short time algorithm of power waveforms fundamental harmonic estimation with use of pronys methods
Autorzy:
Zygarlicki, J.
Mroczka, J.
Powiązania:
https://bibliotekanauki.pl/articles/221769.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power quality
Prony's method
harmonics
measurements
Opis:
This paper presents an example of practical use of Prony's method for monitoring of power waveform fundamental harmonic fluctuations, which is required for the analysis of window synchronizations in frequency analyses in power monitoring systems. The example presented offers verification of the authors' theoretical considerations published earlier in articles about Prony's method and its opportunities for practical use for real life signals. The investigations shown are based on the least squares Prony's method, which, in connection with digital filtrations, enables estimations of fundamental frequency at the rate of even tens of times per one fundamental harmonic period.
Źródło:
Metrology and Measurement Systems; 2011, 18, 3; 371-378
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Passive filter design for three-phase inverter interfacing in distributed generation
Autorzy:
Ahmed, K. H.
Finney, S. J.
Williams, B. W.
Powiązania:
https://bibliotekanauki.pl/articles/262578.pdf
Data publikacji:
2007
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
DG
inverter
grid connected
filtering
damping
harmonics
Opis:
With the growing use of inverters in distributed generation, the problem of injected harmonics becomes critical. These harmonics require the connection of low pass filters between the inverter and the network. This paper presents a design method for the output LC filter in grid coupled applications in distributed generation systems. The design is according to the harmonics standards that determine the level of current harmonics injected into the grid network. Analytical expressions for the maximum inductor ripple current are derived. The filter capacitor design depends on the allowable level of switching components injected into the grid. Different passive filter damping techniques to suppress resonance affects are investigated and evaluated. Simulated results are included to verify the derived expressions.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2007, 13, 2; 49-58
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Poynting Vector Approach to the Study of Power Flow through a Transformer
Autorzy:
Todeschini, G.
Emanuel, A. E.
Powiązania:
https://bibliotekanauki.pl/articles/262661.pdf
Data publikacji:
2007
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
power definitions
power quality
Poynting vector
harmonics
Opis:
This work deals with the flow of the electromagnetic energy through an idealized single-phase transformer supplied with nonsinusoidal voltage and supplying a nonlinear load. The electromagnetic flux components of the energy that flows from primary to secondary as well as the flux of energy stored in and ejected from the dielectric space surrounding the windings are identified and quantified. The electromagnetic flux components are correlated to well known instantaneous powers. These powers are not clever mathematic expedients but correct expressions that mirror the actual physical phenomena and lead to a more realistic interpretation of apparent power and its resolution.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2007, 13, 1; 129-137
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fast Second Order Original Prony’s Method for Embedded Measuring Systems
Autorzy:
Zygarlicki, J.
Powiązania:
https://bibliotekanauki.pl/articles/221161.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Prony’s method
signal processing
harmonics
measurements
Opis:
The paper presents a method of adaptation of the original second order Prony’s method for applications in lowcost digital measurement systems with low computing performance. The presented method can be used in measuring systems where it is important to obtain in real time the values of amplitude, frequency, initial phase and damping coefficient of a single sinusoidal component of an analysed signal. The paper presents optimized, in terms of the number of mathematical operations, implementation of the method in selected embedded devices as well as the calculation times of the method for each platform.
Źródło:
Metrology and Measurement Systems; 2017, 24, 4; 721-728
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Resonant Controller for Higher Harmonics Compensation in PWM rectifiers
Autorzy:
Bobrowska-Rafał, M.
Rafał, K.
Piasecki, S.
Jasiński, M.
Powiązania:
https://bibliotekanauki.pl/articles/115511.pdf
Data publikacji:
2011
Wydawca:
Fundacja na Rzecz Młodych Naukowców
Tematy:
higher harmonics
harmonic compensation
THD
PWM rectifier
Opis:
In this article algorithm for minimizing negative impact of higher harmonics on proper operation of PWM rectifier is presented. Short overview of harmonics compensation methods is also given. Furthermore, Resonance Harmonic Compensator is widely described. Simulation results of compensation of harmonics are presented.
Źródło:
Challenges of Modern Technology; 2011, 2, 2; 23-26
2082-2863
2353-4419
Pojawia się w:
Challenges of Modern Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania wpływu odkształcenia napięcia sieci na przebieg prądu obciążenia wybranych lamp oświetlenia ulicznego
Analysis of load current of street lighting lamps supplied by distorted voltage
Autorzy:
Czapp, S.
Borowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/268709.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
oświetlenie elektryczne
wyższe harmoniczne
electric lighting
harmonics
Opis:
Cechą charakterystyczną większości rodzajów lamp jest odkształcony prąd obciążenia. W niektórych przypadkach odkształcenie prądu może być duże, co niekorzystnie wpływa na sieć zasilającą. Odkształcenie to pogłębia się, gdy lampy są zasilane odkształconym napięciem. W artykule przedstawiono wyniki badań prądu obciążenia następujących lamp stosowanych w oświetleniu ulicznym: lampy sodowej wysokoprężnej, lampy sodowej niskoprężnej i lampy ledowej. W pierwszym etapie badań lampy zasilano napięciem o pomijalnym odkształceniu, co pozwoliło wyznaczyć referencyjne przebiegi ich prądu obciążenia. Następnie zasilano je napięciem o coraz większym odkształceniu.
A characteristic feature of most types of lamps is distorted load current. In some cases, the current distortion can be strong, which negatively affects the supply network. Current distortion is increased when the lamps are supplied by distorted voltage. The paper presents the results of the load current testing of selected lamps used in street lighting (high pressure sodium lamp, low pressure sodium lamp and LED lamp). In the first stage of the investigation the supply voltage was sinusoidal, which allowed for evaluation the reference waveform of the load current. Further, the supply voltage was of increasingly distorted.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2015, 46; 25-30
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Adaptive Control Strategy for a Low-Ripple Boost Converter in BLDC Motor Speed Control
Autorzy:
Wang, Haifeng
Zhang, Haili
Powiązania:
https://bibliotekanauki.pl/articles/1955989.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
boost converter
BLDC
harmonics
observer
feedback control
Opis:
Conventional boost converters are widely used for connecting low-voltage power sources and inverters in motor control. However, a large filter capacitor bank is often used to reduce DC-link ripples that occur when an inverter is connected to a boost converter. Otherwise, significant voltage and current perturbations can impact on battery performance degradation and cause torque ripple, speed ripple and vibration in brushless DC (BLDC) motors. To suppress the converter’s DC-link ripple, this paper proposes a new control strategy for boost converter controller to generate low-ripple DC-link voltage or current at different motor speeds. In the proposed method, observers are designed to adaptively estimate the DC-link voltage and current harmonics. The harmonic terms are used as feedback signals to calculate the DC converter’s duty cycle. The entire control model is implemented on an embedded system, and its robustness is verified by simulation and experimental results that show the DC-link voltage and current ripples can be reduced by about 50% and 30%, respectively.
Źródło:
Power Electronics and Drives; 2021, 6, 41; 242-259
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Designing a group of single-branch filters taking into account their mutual influence
Autorzy:
Klempka, R.
Powiązania:
https://bibliotekanauki.pl/articles/140911.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
passive filter
compensation of reactive power
harmonics
Opis:
Single-branch filters are still popular and are commonly used for power quality improvement purposes. Analysis of a single-branch filter is a relatively simple task. Although individual filters tuned to specific harmonics can be easily designed, after connecting them into a group it turns out that the capacitance and inductance mutually influence each other, distorting the resulting frequency characteristics. This article presents a matrix method for design a group of single-branch filters, so that the resultant frequency characteristic satisfies the design requirements including the requirements for location of the frequency characteristic maxima. Designer indicates the frequencies of the parallel resonances.
Źródło:
Archives of Electrical Engineering; 2014, 63, 1; 81-92
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Active power filters – optimization of sizing and placement
Autorzy:
Maciążek, M.
Grabowski, D.
Pasko, M.
Powiązania:
https://bibliotekanauki.pl/articles/200825.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power quality
active power filter
harmonics
optimization
Opis:
The significant problem of compensator placement and sizing in electrical networks has been analyzed in the paper. The compensation is usually realized by means of passive or active power filters. The former solution is widely used mainly because of the economical reasons, but the latter one becomes more and more popular as the number of nonlinear loads increases. Regardless of the compensator type the most important goal consists in voltage and current distortion drop below levels imposed by standards. Nevertheless, the desired effects should be achieved with the minimum cost. So far a few objective functions have been proposed for this optimization problem. It is claimed that minimization of the compensator currents leads also to the minimum costs. This paper shows that such simplified approach could lead to suboptimal solutions and in fact a function g(·) reflecting the relation between the compensator size and its price must be incorporated into objective functions. Moreover, in this case it is very easy to compare solutions obtained using compensators offered by different suppliers - it is enough to change the function g(·). Theoretical considerations have been illustrated by an example of active power filter allocation and sizing.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2013, 61, 4; 847-853
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pomiary jakości energii w eksploatacji instalacji i urządzeń elektrycznych zakładu przemysłowego
Power quality measurements in operation of electrical devices and systems in industry
Autorzy:
Olesz, M.
Powiązania:
https://bibliotekanauki.pl/articles/267318.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
jakość energii elektrycznej
bateria kondensatora
zapady harmoniczne
przepięcia harmoniczne
power quality energy
capacitor banks
dips harmonics
overvoltages harmonics
Opis:
W referacie opisano wyniki pomiarów dla instalacji elektrycznych zakładu przemysłowego z szczegółowym uwzględnieniem baterii kondensatorów pracujących w obecności wyższych harmonicznych. Występowanie wysokich wartości harmonicznych prądowych w warunkach rezonansu pojemności baterii z indukcyjnością transformatora może być przyczyną przegrzewania i uszkadzania izolacji kondensatorowej. Analiza pomiarów z rejestratorów jakości energii elektrycznej umożliwia wprowadzenie zmian w instalacjach elektrycznych poprawiających bezpieczeństwo użytkowania oraz zmniejszenie kosztów eksploatacyjnych.
The paper presents the results of measurements of electrical industrial plant with a detailed consideration of capacitors operating in a harmonic environment. The seventh harmonics of supply voltage, reaching high average value of 16% has been detected in tested installation. Due to the resonance phenomena, amplification and propagation of current harmonics causes in capacitor banks overheating as well as deforming the cases. Furthermore recordings of transient states, allowed to register overvoltages involved while switching on the capacitor bank. Data analysis of power quality recorder in electrical installations improving safety and reducing operating costs.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2016, 50; 71-74
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electromagnetic Scattering by a Cylinder in a Lossy Medium of an Inhomogeneous Elliptically Polarized Plane Wave
Autorzy:
Mangini, Fabio
Dinia, Lorenzo
Frezza, Fabrizio
Powiązania:
https://bibliotekanauki.pl/articles/309521.pdf
Data publikacji:
2019
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
electromagnetic scattering
inhomogeneous wave dispersion
vectorial cylindrical-harmonics
Opis:
In this paper, a rigorous theoretical approach, adopted in order to generalize the Vectorial CylindricalHarmonics (VCH) expansion of an inhomogeneous elliptically polarized plane wave, is presented. An application of the VCH expansion to analyze electromagnetic field scattered by an infinite circular cylinder is presented. The results are obtained using the so-called complex-angle formalism reaching a superposition of Vectorial Cylindrical-Harmonics. To validate the method, a Matlab code was implemented. Also, the validity of the methodology was confirmed through some comparisons between the proposed method and the numerical results obtained based on the Finite Element Method (FEM) in the canonical scenario with a single cylinder.
Źródło:
Journal of Telecommunications and Information Technology; 2019, 4; 36-42
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Study of Higher Harmonics Content in Street Lighting System Current
Eksperymentalne badania zawartości wyższych harmonicznych w przebiegach prądów w instalacji oświetlenia uliczneg
Autorzy:
Bieliński, K.
Cieślik, S.
Powiązania:
https://bibliotekanauki.pl/articles/397115.pdf
Data publikacji:
2016
Wydawca:
ENERGA
Tematy:
wyższe harmoniczne
oświetlenie uliczne
higher harmonics
street lighting
Opis:
Due to energy efficiency improvement requirements, street lighting system operators tend to reduce the electricity consumed by the lights themselves, and also minimize losses in the system. Smart lighting control systems are commonly used for this purpose. An important aspect of electricity power and quality issues is the higher harmonics content in street lighting system current, which was the subject of experimental research the results of which were presented in this paper.
Wymagania dotyczące poprawy efektywności energetycznej skłaniają eksploatatorów oświetlenia ulicznego do zmniejszenia ilości energii zużywanej przez same lampy, ale również do minimalizacji strat energii w instalacji. W tym celu dużym zainteresowaniem cieszą się inteligentne systemy sterowania oświetleniem. Jednym z ważnych aspektów dotyczących zagadnień energetycznych oraz jakościowych energii elektrycznej jest zawartość wyższych harmonicznych prądów w instalacji oświetlenia ulicznego, co było przedmiotem badań eksperymentalnych, których wyniki zaprezentowano w tym artykule.
Źródło:
Acta Energetica; 2016, 2; 45-52
2300-3022
Pojawia się w:
Acta Energetica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Isotropic distributions in hcp crystals
Autorzy:
Kontrym-Sznajd, G.
Powiązania:
https://bibliotekanauki.pl/articles/148416.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
Brillouin zone
lattice harmonics
special directions
isotropic distribution
Opis:
Some anisotropic quantities in crystalline solids can be determined from their knowledge along a limited number of sampling directions. The importance of the choice of such directions is illustrated on the example of estimating, from angular correlation of annihilation radiation data, the isotropic electron momentum density in Gd.
Źródło:
Nukleonika; 2015, 60, No. 4, part 1; 741-744
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rezonans w układach nieliniowych z uwzględnieniem transformatora zasilającego
A resonance in nonlinear circuits supplied by transformer
Autorzy:
Michaluk, A.
Powiązania:
https://bibliotekanauki.pl/articles/152104.pdf
Data publikacji:
2008
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
wyższe harmoniczne
rezonans
transformator
higher harmonics
resonance
transformer
Opis:
W artykule omówiono zjawiska rezonansowe występujące przy udziale wyższych harmonicznych. Zjawiska te są niejednoznacznie interpretowane w literaturze, w związku z czym przedstawiono mechanizm powstawania wyższych harmonicznych w sieci elektroenergetycznej, który wyjaśnia przyjęte przez autora stanowisko odnośnie występujących zjawisk rezonansowych. Przedstawiono także przykładowy przebieg i skutki awarii w sieci przemysłowej spowodowanej wystąpieniem rezonansu.
In this article phenomenon of resonance with participation of higher harmonics are discussed. The phenomenon are ambiguously interpreted in literature, thus a mechanism of generating of higher harmonics in electrical networks is presented. The mechanism explains the stand taken by the authors on higher harmonics resonance phenomenon. As an example a course and results of resonance breakdown in industrial network are shown.
Źródło:
Pomiary Automatyka Kontrola; 2008, R. 54, nr 6, 6; 399-401
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Implementacja uogólnionego algorytmu szczególnego próbkowania dla wyznaczania harmonicznej podstawowej w środowisku LabVIEW
Implementation of generalized particular sampling algorithm for determining the fundamental harmonic in LabVIEW environment
Autorzy:
Ziółko, M.
Powiązania:
https://bibliotekanauki.pl/articles/267594.pdf
Data publikacji:
2013
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
wyższe harmoniczne
próbkowanie
filtracja
filtering
harmonics
particular sampling
Opis:
Praca dotyczy opisu oraz implementacji uogólnionego algorytmu szczególnego próbkowania dla wyznaczania amplitudy harmonicznej podstawowej w środowisku LabVIEW. Algorytm szczególnego próbkowania umożliwia wyodrębnienie informacji o wartości amplitudy harmonicznej podstawowej ze spróbkowanego, odkształconego sygnału przy zastosowaniu stosunkowo prostych środków technicznych. Aplikacja może mieć zastosowanie w urządzeniach pomiarowych wyposażonych w prosty mikrokontroler. Zaleta opracowanego oprogramowania jest jego elastyczność, polegającą na automatycznym doborze zestawu próbek niezbędnych do filtracji wyższych harmonicznych, spełniającym zadeklarowane przez użytkownika wymagania.
The paper presents an implementation of generalized Particular Sampling Algorithm for determination the fundamental harmonic in LabVIEW environment. This algorithm is used to extract information about fundamental harmonic from distorted sampling signal. Information about the fundamental harmonic of current or voltage is substantial in many types of measurements. For example, some parameters in the protective measures in the power systems, like loop impedance or ground impedance, are calculated using such information. These parameters are very important in evaluation of effectiveness of protection against electric shocks. Extracted information about the fundamental harmonic with the application of Particular Sampling Method is possible using simplified technical resources compared to FFT algorithm. The measurement device based on Particular Sampling Method can be equipped with a simple microcontroller. In the literature a concrete implementations of this method were used. The sampling program, which was created so far manually, has been determined by the set of eliminated harmonics. The main advantage of presented software developed in LabVIEW environment is its flexibility, i.e. the sampling program is created automatically. The results obtained from the use of this software are consistent with the results of previous studies.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2013, 34; 81-84
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza widmowa napięć w sieci elektroenergetycznej w ujęciu normatywnym
The spectral analysis of voltages in power network in standard depiction
Autorzy:
Otomański, P.
Wiczyński, G.
Powiązania:
https://bibliotekanauki.pl/articles/155767.pdf
Data publikacji:
2007
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
harmoniczne
interharmoniczne
grupowanie
podgrupowanie
harmonics
interharmonics
grouping
subgrouping
Opis:
Ocena jakości energii elektrycznej w sieciach elektroenergetycznych wykorzystuje zestaw wielkości normatywnych i uzupełniających. Wśród tych wielkości znajdują się dwie miary zawartości harmonicznych w napięciu: widmo amplitudowe (czyli zestaw wartości poszczególnych harmonicznych) oraz współczynnik odkształcenia THD. Specyfikacja normatywna obu wielkości określa warunki pomiaru bardziej rozbudowane niż zazwyczaj występujące w literaturze z podstaw elektrotechniki i teorii sygnałów. W artykule opisano specyfikacje normatywne miar harmonicznych napięć w sieci elektroenergetycznej. Przedstawiono interpretację norm prowadzącą do sprecyzowania pomiaru poszczególnych harmonicznych i współczynnika THD. Zamieszczono wyniki badań weryfikujących zgodność działania dwóch urządzeń pomiarowych z wymaganiami normatywnymi.
The electric power quality evaluation in electrical power networks is a complex measuring task carried out with the use of a set of standard and complementary quantities. Among these quantities two measures of harmonic content in voltage can be mentioned: spectrum amplitude and coefficient THD. Standard specification of voltage harmonic measures in electrical power networks was presented in the paper. Measurement results, testing the compatibility of two measurement devices for standard requirements, were presented.
Źródło:
Pomiary Automatyka Kontrola; 2007, R. 53, nr 9 bis, 9 bis; 665-668
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Resistance Approximation In High Harmonic Frequencies
Autorzy:
Sayenko, Y. L.
Kukhun, W.
Powiązania:
https://bibliotekanauki.pl/articles/262733.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
skin effect
high harmonics
propagation
induction
conductor
frequency
Opis:
The problem of consideration of the resistance in calculation of non-sinusoidal regimes in electrical networks is considered in article. It is shown the necessity of taking in account the skin effect in harmonic frequencies. Using general electromagnetic field theory in condition medium and Bessel’s function allow to obtain expressions of resistance approximations in high harmonics frequencies for conductors of round cross-sectional areas.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2009, 15, 2; 43-46
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Harmonic compensation using the sliding DFT algorithm for three-phase active power filter
Autorzy:
Sozański, K. P.
Powiązania:
https://bibliotekanauki.pl/articles/262743.pdf
Data publikacji:
2006
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
active filters
harmonics
DSP
power quality
power factor correction
Opis:
This paper describes the sliding discrete Fourier transform (DFT) algorithm as an alternative for typical DFT used for spectrum analysis and synthesis. As an example a control circuit for a three-phase 75 kVA parallel active power filter (APF) is used. Such filters have been built and tested. Some illustrative, experimental results are also presented in the paper. The control algorithms of the proposed APF are implemented in the fixed-point digital signal processor TMS320C50. The presented control APF algorithm is a good alternative to classical APF control algorithms, because it allows easy selection of control parameters in mains currents: imbalance, reactive power or harmonics contents. In the proposed circuit transient performance of APF is improved using non-causal predictive current compensation.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2006, 12, 2; 15-20
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adjustable Generator of Edge-Rounded Trapezoidal Waveforms
Autorzy:
Jankowski, M.
Jabłoński, G.
Powiązania:
https://bibliotekanauki.pl/articles/227124.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
trapezoidal waveform generation
edge-rounding
signal shaping
harmonics reduction
Opis:
An approach to design a trapezoidal waveform generator with edge-rounding functionality is presented. The paper describes circuit able to produce edge-rounded trapezoidal waveform. Adjustment of numerous waveform parameters is possible. The signal path inside the circuit is very short. Most of circuitry required for waveform edge-rounding and adjustment is placed outside the signal path and works in DC mode.
Źródło:
International Journal of Electronics and Telecommunications; 2012, 58, 3; 213-218
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Hartogs-type series for harmonic functions on Hartogs domains in $ℝ^n × ℝ^m$, m ≥ 2
Autorzy:
Ligocka, Ewa
Powiązania:
https://bibliotekanauki.pl/articles/1294106.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
harmonic functions
harmonic polynomials
spherical harmonics
conjugate harmonic functions
Opis:
We study series expansions for harmonic functions analogous to Hartogs series for holomorphic functions. We apply them to study conjugate harmonic functions and the space of square integrable harmonic functions.
Źródło:
Annales Polonici Mathematici; 1999, 71, 2; 151-160
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Error Analysis of Sound Source Directivity Interpolation Based on Spherical Harmonics
Autorzy:
Szwajcowski, Adam
Krause, Daniel
Snakowska, Anna
Powiązania:
https://bibliotekanauki.pl/articles/1953503.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
sound source directivity
spherical harmonics
interpolation error
sparse measurements
Opis:
Precise measurement of the sound source directivity not only requires special equipment, but also is time-consuming. Alternatively, one can reduce the number of measurement points and apply spatial interpolation to retrieve a high-resolution approximation of directivity function. This paper discusses the interpolation error for different algorithms with emphasis on the one based on spherical harmonics. The analysis is performed on raw directivity data for two loudspeaker systems. The directivity was measured using sampling schemes of different densities and point distributions (equiangular and equiareal). Then, the results were interpolated and compared with these obtained on the standard 5° regular grid. The application of the spherical harmonic approximation to sparse measurement data yields a mean error of less than 1 dB with the number of measurement points being reduced by 89%. The impact of the sparse grid type on the retrieval error is also discussed. The presented results facilitate optimal sampling grid choice for low-resolution directivity measurements.
Źródło:
Archives of Acoustics; 2021, 46, 1; 95-104
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A hybrid parallel active filter / off-line UPS unit for computer loads
Autorzy:
Ghennam, T.
Darwish, M.
Powiązania:
https://bibliotekanauki.pl/articles/262760.pdf
Data publikacji:
2008
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
active filters
UPS systems
computer power supplies
current harmonics
Opis:
A hybrid parallel active filter / off-line uninterruptible power supply (UPS) system is proposed. The hybrid system contains a single inverter which acts as a parallel active filter during the normal mode of operation (when the AC supply is available); and also supplies the load with energy from the UPS back-up battery during the back-up mode of operation (when the AC supply is not available or is beyond the preset tolerance). In both modes of operations the inverter is controlled in such way so that the line current is a pure sinusoid. This is to improve the input power factor and to eliminate the current harmonics in the first mode and to remove any stress on the back-up battery caused by the discharging during the second mode of operation. A full simulation results and an experimental setup is presented together with a closed loop control algorithm.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2008, 14, 2; 41-48
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Power Quality Measurements – the Importance of Traceable Calibration
Autorzy:
van den Brom, H. E.
Hoogenboom, D.
Powiązania:
https://bibliotekanauki.pl/articles/262833.pdf
Data publikacji:
2013
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
calibration
power quality
reference system
standardization
traceability
harmonics
flicker
Opis:
Standardization has contributed significantly to comparable analysis methods for power quality parameters. However, in order to have undisputable results, the measurement values themselves should also be comparable. This can only be achieved by traceability to international measurement standards. For this reason, at VSL, the Dutch national metrology institute, a fully traceable reference setup was developed for calibration of power quality analyzers. In this paper, we show the calibration results of the critical components of the reference setup, we demonstrate its applicability by test measurements on the public low-voltage supply system for specific parameters, and show its ability to simulate and generate events that can be detected and analyzed by both the equipment under test and the reference setup.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2013, 16, 1; 25-29
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the maximal operator associated with the free Schrödinger equation
Autorzy:
Wang, Sichun
Powiązania:
https://bibliotekanauki.pl/articles/1220332.pdf
Data publikacji:
1997
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
free Schrödinger equation
maximal functions
spherical harmonics
oscillatory integrals
Opis:
For d > 1, let $(S_{d}f)(x,t) = ʃ_{ℝ^n} e^{ix·ξ} e^{it|ξ|^d} f̂(ξ)dξ$, $x ∈ ℝ^n$, where f̂ is the Fourier transform of $f ∈ S (ℝ^n)$, and $(S_{d}*f)(x) = sup_{0 < t < 1} |(S_{d}f)(x,t)|$ its maximal operator. P. Sjölin ([11]) has shown that for radial f, the estimate (*) $(\int_{|x| < R} |(S_{d}*f)(x)|^p dx)^{1//p} ≤ C_{R}∥f∥_{H_{1//4}}$ holds for p = 4n//(2n-1) and fails for p > 4n/(2n-1). In this paper we show that for non-radial f, (*) fails for p > 2. A similar result is proved for a more general maximal operator.
Źródło:
Studia Mathematica; 1997, 122, 2; 167-182
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study on the effect of harmonie components of the current supplying an induction motor with reactive power compensation with the use of capacitors on the power loss and voltage variations
Autorzy:
Nawrowski, R.
Stein, Z.
Zieliński, M.
Powiązania:
https://bibliotekanauki.pl/articles/97224.pdf
Data publikacji:
2014
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
induction motor
current and voltage harmonics
power loss compensation
Opis:
The paper presents an analysis of the effect of voltage harmonics on the power loss in an LV line supplying an induction motor with reactive power compensation, with the use of capacitors, and analysis of the values of output voltage of an MV/LV transformer depending on the load type and value.
Źródło:
Computer Applications in Electrical Engineering; 2014, 12; 275-287
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Near perfect reconstruction filter banks for power quality analysis
Autorzy:
Taskovski, D.
Koleva, L.
Milchevski, A.
Dimcev, V.
Powiązania:
https://bibliotekanauki.pl/articles/220392.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power quality
power harmonics
disturbance classification
quadrature mirror filters
Opis:
The wavelet transform has been successfully used in the area of power quality analysis. There are many published papers with methods for power quality disturbance classification or harmonics measurement, which use wavelet transform. However, the properties of the wavelet transform can drastically vary from the choice of the wavelet. In this paper we analyze the influence of the choice of the wavelet to the accuracy of the power quality classification method and to high frequency harmonics measurements. Additionally to the well known wavelet filters we introduce near perfect reconstruction filter banks. The simulation results indicate that these filter banks are a good choice for classification of power quality disturbances, especially in the presence of noise and for high frequency harmonics measurements.
Źródło:
Metrology and Measurement Systems; 2013, 20, 3; 359-370
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhancing capabilities of Atomic Force Microscopy by tip motion harmonics analysis
Autorzy:
Babicz, S.
Smulko, J.
Zieliński, A.
Powiązania:
https://bibliotekanauki.pl/articles/199918.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
atomic force microscopy (AFM)
harmonics
van der Waals forces
Opis:
Motion of a tip used in an atomic force microscope can be described by the Lennard-Jones potential, approximated by the van der Waals force in a long-range interaction. Here we present a general framework of approximation of the tip motion by adding three terms of Taylor series what results in non-zero harmonics in an output signal. We have worked out a measurement system which allows recording of an excitation tip signal and its non-linear response. The first studies of spectrum showed that presence of the second and the third harmonics in cantilever vibrations may be observed and used as a new method of the investigated samples characterization.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2013, 61, 2; 535-539
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Harmonics in the current powering selected low and medium power devices and their impact on power losses
Autorzy:
Nawrowski, R.
Stein, Z.
Zielińska, M.
Powiązania:
https://bibliotekanauki.pl/articles/97608.pdf
Data publikacji:
2016
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
electromagnetic compatibility of electric circuits
harmonics in current and voltage
Opis:
The paper deals with the issues related to currents of higher harmonics occurring in low and medium power circuits, using the Mcad software. Furthermore, it presents the effect of current harmonics on the root–mean–square value of these currents, and thus on the current load of conductors, especially the neutral (zero) conductor. Subject to discussion are also the effects of higher current harmonics on the performance of the power grid.
Źródło:
Computer Applications in Electrical Engineering; 2016, 14; 101-112
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High voltage harmonics induced modifications of PD phase-resolved patterns
Autorzy:
Florkowski, M.
Florkowska, B.
Zydroń, P.
Powiązania:
https://bibliotekanauki.pl/articles/141372.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
electrical insulation system
diagnostics
harmonics
partial discharges
phase-resolved patterns
Opis:
Partial discharges (PD) are influencing electrical insulating systems of high voltage electrical devices. Typically, in laboratory and diagnostics AC tests focused on measuring and analysis of PD, a pure sinusoidal voltage waveform is assumed. However, in practice the spectral content of the working voltage is rarely so ideal and additional spectral components have a significant impact on the discharge behaviour in electrical insulation systems. In this paper the influence of voltage harmonics on PD behaviour and phase-resolved PD patterns evolution is analysed. The presented experiments were conducted on a specimen representing a gaseous inclusion embedded in electrical insulation. The experimental results showed that various harmonic compositions superimposed on the fundamental sinusoidal waveform have a significant impact on PD intensity and maximum charge. In consequence, the derived patterns of PD phase, and magnitude distributions are distorted, and statistical parameters calculated on their basis are changed. In certain environments, neglecting harmonic content in the testing voltage may lead to a misleading interpretation and assessment of PD severity.
Źródło:
Archives of Electrical Engineering; 2018, 67, 2; 231--246
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on hybrid topology of single-switch ICPT for battery charging
Autorzy:
Zhang, Guangzong
Wang, Chunfang
Zheng, Jianfen
Li, Houji
Powiązania:
https://bibliotekanauki.pl/articles/949898.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
constant current
constant voltage
higher harmonics
ICPT
single-switch
inverter
Opis:
In order to realize constant current and constant voltage charging for batteries by inductively coupled power transfer (ICPT) technology, a single-switch CL/LCL circuit is designed. The single-switch CL/LCL circuit is composed of a CL/LCL compensation network and single-switch inverter. The proposed circuit is compared with the traditional constant current and constant voltage circuit in the structure. The operating process of the single-switch CL/LCL circuit and the principle to realize a zero-voltage switch (ZVS) are analysed in detail in this paper. The voltage gain and current gain of the circuit are calculated, which demonstrates that the circuit is able to suppress higher harmonics strongly. By using Fourier decomposition, the voltage on the primary-side compensation capacitor can be obtained. After constructing the equivalent mutual inductance model of the circuit, the formulas and parameters are deduced and calculated. Finally, an experiment platform is built to verify the proposed circuit can realize constant current and constant voltage.
Źródło:
Archives of Electrical Engineering; 2020, 69, 4; 841-855
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of BLDCM with a double 3-phase stator winding and back EMF harmonics
Autorzy:
Drozdowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/950656.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
brushless DC motor
double stator winding
harmonics of back EMF
Opis:
In this paper the mathematical model of the brushless DC motor (BLDCM) with a double 3-phase stator winding is analysed. Both the 3-phase windings are mutually displaced by 30 electrical degree. Special care has been sacrificed to influence of higher harmonics of induced electromotive forces (EMF) on electromagnetic torque and zero sequence voltages that may be used for sensorless control. The mathematical model has been presented in natural variables and, after transformation to symmetrical components, in a vector form. This allows, from one side, for formulating the equivalent circuit suitable for circuit oriented simulators (e.g.: Spice, SimPowerSystems of Simulink) and, from the other point of view, for analysis of higher harmonics influence on control possibilities. These considerations have been illustrated with some results of four quadrant operation obtainded due to simulation at automatic control.
Źródło:
Archives of Electrical Engineering; 2015, 64, 1; 53-66
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Harmonics on the Working Efficiency of a 6/1.2 kV Transformer in a Pit Mine
Autorzy:
Ngo, Xuan Cuong
Do, Nhu Y.
Powiązania:
https://bibliotekanauki.pl/articles/2019275.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
harmonics
working efficiency
transformer
pit mine
wyższe harmoniczne
efektywność
kopalnie
Opis:
Explosion-proof transformers 6/1.2 kV is important electrical equipment responsible for supplying electricity in underground mine electrical networks. A failure of this transformer will cause an interruption in the power supply and loss of safety in underground mining. Usually, explosion-proof transformers in underground mine electrical networks are designed and manufactured to work with ideal parameters such as sinusoidal currents, and the network structure is symmetrical. However, today in underground mine electric networks, many power electronics are connected to the network, such as inverters and soft starters. As a result, a current flowing through the transformer is non-sinusoidal, overloading the transformer even by working with the design specifications. This paper studies the influence of harmonics on the working efficiency of a 6/1.2 kV transformer in a pit mine. Research results suggest reasonable solutions for transformer operation to ensure longevity and not cause damage to the transformer.
Źródło:
Inżynieria Mineralna; 2021, 2; 149--156
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oddziaływanie energoelektronicznych przekształtników mocy zasilających duże odbiory na górnicze sieci elektroenergetyczne. Część II
Impact of power electronics converters for supply of high-power receivers on the mining power networks. Part II
Autorzy:
Wosik, J.
Hefczyc, M.
Miedziński, B.
Powiązania:
https://bibliotekanauki.pl/articles/186717.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technik Innowacyjnych EMAG
Tematy:
górnicza sieć elektroenergetyczna
wyższe harmoniczne
higher harmonics
mining power network
Opis:
W artykule omówiono sposoby opisu zawartości wyższych harmonicznych w odkształconych przebiegach napięć i prądów. Scharakteryzowano skutki występowania wyższych harmonicznych w kablowych sieciach zasilających odbiory górnicze. Przedstawiono wnioski wynikające z analizy pracy tych układów w obecności wyższych harmonicznych.
The paper shows the methods how to describe a content of higher harmonics in deformed voltage and current waves. The effects of occurrence of higher harmonics in cable mining power networks supplying the mining receivers have been characterized. The conclusions relating to the analysis of operation of the mining receivers in presence of the higher harmonics have been presented.
Źródło:
Mechanizacja i Automatyzacja Górnictwa; 2009, R. 47, nr 3, 3; 19-24
0208-7448
Pojawia się w:
Mechanizacja i Automatyzacja Górnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantitative Evidence for Direct Effects Between Earth-Ionosphere Schumann Resonances and Human Cerebral Cortical Activity
Autorzy:
Saroka, K. S.
Persinger, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/412383.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Schumann harmonics
quantitative electroencephalography
brain-ionosphere similarities
picoTesla intensities
correlations
Opis:
The multiple quantitative similarities of basic frequencies, harmonics, magnetic field intensities, voltages, band widths, and energetic solutions that define the Schumann resonances within the separation between the earth and ionosphere and the activity within the human cerebral cortices suggest the capacity for direct interaction. The recent experimental demonstration of the representations of the Schumann resonances within the spectral densities of normal human quantitative electroencephalographic (QEEG) activity suggests a casual interaction. Calculations supported by correlations between amplitudes of the global Schumann resonances measured several thousands of km away (which were nearly identical to our local measurements) and the coherence and current densities or these frequency bands between cerebral hemispheres for a large population of human QEEG measures indicate that such interaction occurs. The energies are within the range that would allow information to be exchanged between cerebral and Schumann sources. The near-identical solution for current density from the increasing human population and background vertical electric fields suggests that changes in the former might determine the degree of coherence between the Schumann resonances. Direct comparisons of local Schumann measurements and brain activity exhibited powerful intermittent coherence within the first three harmonics. Implications of the contributions of solar transients, surface temperature, and rapidly developing technologies to modify the ionosphere‟s Schumann properties are considered.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 20, 2; 166-194
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Investigations of the Upqc Arrangement
Autorzy:
Benysek, G.
Powiązania:
https://bibliotekanauki.pl/articles/262602.pdf
Data publikacji:
2006
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
power quality
power flow control
harmonics compensation
reactive power compensation
Opis:
This paper presents the fundamental properties and dependences describing the UPQC (Unified Power Quality Conditioner) arrangements. The UPQC devices simultaneously permit to fulfill the following functions: voltage and current harmonics compensation, network voltage and load current symmetrization as well as network voltage stabilization and power flow control. The selected results of the experimental investigations conducted on the small power laboratory model have been described. Applied method for DC link capacity selection was talked over in details and confirmed with experimental results. Results of experimental investigations, including operation of the UPQC arrangement in case of thyristor rectifier load were also introduced.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2006, 12, 1; 27-34
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Harmonics on the Working Efficiency of a 6/1.2 kV Transformer in a Pit Mine
Autorzy:
Ngo, Xuan Cuong
Do, Nhu Y.
Powiązania:
https://bibliotekanauki.pl/articles/2019271.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
harmonics
working efficiency
transformer
pit mine
wyższe harmoniczne
efektywność
kopalnie
Opis:
Explosion-proof transformers 6/1.2 kV is important electrical equipment responsible for supplying electricity in underground mine electrical networks. A failure of this transformer will cause an interruption in the power supply and loss of safety in underground mining. Usually, explosion-proof transformers in underground mine electrical networks are designed and manufactured to work with ideal parameters such as sinusoidal currents, and the network structure is symmetrical. However, today in underground mine electric networks, many power electronics are connected to the network, such as inverters and soft starters. As a result, a current flowing through the transformer is non-sinusoidal, overloading the transformer even by working with the design specifications. This paper studies the influence of harmonics on the working efficiency of a 6/1.2 kV transformer in a pit mine. Research results suggest reasonable solutions for transformer operation to ensure longevity and not cause damage to the transformer.
Źródło:
Inżynieria Mineralna; 2021, 2; 149--156
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wyznaczanie wartości parametrów odkształcenia napięć i prądów z zastosowaniem rejestratora wartości chwilowych przeznaczonego do monitorowania pracy urządzeń odlewniczych
Determination of Deformation Parameters of Voltage and Current Using the Instantaneous Values Recorder Designed for Monitoring of the Operation of Foundry Devices
Autorzy:
Ziółkowski, E.
Smyksy, K.
Fedoryszyn, A.
Brzeziński, M.
Powiązania:
https://bibliotekanauki.pl/articles/381909.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
odkształcenia napięć
odkształcenia prądów
harmoniczne napięć
harmoniczne prądów
układ zasilania
urządzenia odlewnicze
voltages deformations
currents deformations
harmonics voltages
harmonics currents
supply system
foundry machine
Opis:
W artykule opisano dalsze prace związane z rozszerzeniem funkcjonalności rejestratora wartości chwilowych napięć i prądów przeznaczonego do monitorowania pracy urządzeń odlewniczych zasilanych z sieci elektroenergetycznej jedno- lub trójfazowej. W ich ramach opracowano i wdrożono odpowiednie algorytmy obliczeniowe wzbogacające oprogramowanie przyrządu. Do analizy chwilowych przebiegów napięcia i prądu wykorzystano podawane w literaturze syntetyczne wskaźniki charakteryzujące wyżej wymienione przebiegi.
The article describes further work related to the extension of functionality of instantaneous values recorder of voltages and currents designed to monitor of the foundry devices operation. Such devices can be supplied from the single or three-phase power grid. In this framework the appropriate computational algorithms have been developed and implemented. It has enriched the device software. For analysis of instantaneous voltage and current values have been used synthetic indicators characterizing the above-mentioned waveforms (reported in the technical literature).
Źródło:
Archives of Foundry Engineering; 2015, 15, 4 spec.; 163-166
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Some Properties of Instantaneous Active and Reactive Powers
Autorzy:
Czarnecki, L. S.
Powiązania:
https://bibliotekanauki.pl/articles/262612.pdf
Data publikacji:
2013
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
active power filters
CPC theory
harmonics
non-sinusoidal systems
switching compensators
Opis:
Some features of the instantaneous active and reactive powers p and q , not reported earlier, are discussed in this paper. It is shown that oscillating components and of these powers may not depend on the order of the load current harmonic. It was shown, moreover, that a load supplied with a nonsinusoidal voltage may not be distinguished in terms of p and q powers from a harmonics generating load (HGL) supplied with a sinusoidal voltage. This observation is important for compensator control. Also it was shown that the instantaneous reactive power q cannot be interpreted as a measure of amount of energy exchanged between supply lines of a load or as amount of energy rotating around such lines, as it was suggested in some publications on the IRP p-q Theory. A phenomenon of energy rotation or exchange between lines does not exist.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2013, 16, 1; 11-17
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-50 z 154

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