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Wyszukujesz frazę "power method" wg kryterium: Wszystkie pola


Tytuł:
A hybrid maximum power point search method using temperature measurements in partial shading conditions
Autorzy:
Mroczka, J.
Ostrowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/221430.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
maximum power point
partial shading
perturb and observe
temperature measurement
Opis:
Photovoltaic panels have a non-linear current-voltage characteristics to produce the maximum power at only one point called the maximum power point. In the case of the uniform illumination a single solar panel shows only one maximum power, which is also the global maximum power point. In the case an irregularly illuminated photovoltaic panel many local maxima on the power-voltage curve can be observed and only one of them is the global maximum. The proposed algorithm detects whether a solar panel is in the uniform insolation conditions. Then an appropriate strategy of tracking the maximum power point is taken using a decision algorithm. The proposed method is simulated in the environment created by the authors, which allows to stimulate photovoltaic panels in real conditions of lighting, temperature and shading.
Źródło:
Metrology and Measurement Systems; 2014, 21, 4; 733-740
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Power supply risk assessment method for relay protection system faults
Autorzy:
Tuyou, S.
Jiekang, W.
Weideng, Y.
Anan, D.
Powiązania:
https://bibliotekanauki.pl/articles/141134.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
reduced power supply load power
relay protection systems
risk value
power supply risk assessment
Opis:
The influence and the potential risk due to hidden faults of a relay protection system on power supply in distribution systems are paid more and more attention to. A probability analysis method is used to analyse fault characteristics and action mechanism of dominant faults, hidden misoperation and non-operation of the relay protection systems, and failure probability model of relay protection system is constructed and simplified. The effects of dominant faults, hidden misoperation and non-operation of the relay protection systems on the reduced power supply load power are analysed, and a probabilistic model for reduced power supply load power is constructed by three parts corresponding to dominant faults, hidden misoperation and non-operation. A probability calculation method of power supply risk occurrence due to hidden faults of relay protecttion system is proposed considering the fault probability of the relay protection systems, the frequency of the hidden faults occurring in operation period, the reduced power supply load power or load power outage, and the connection mode of the in-lines, out-lines and transformers in a substation. The feasibility and applicability of the proposed method for estimation of risk value probability of the relay protection systems is verified by two studied examples.
Źródło:
Archives of Electrical Engineering; 2016, 65, 4; 803-814
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A combined method for wind power generation forecasting
Autorzy:
Le, Tuan-Ho
Powiązania:
https://bibliotekanauki.pl/articles/1955200.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
autoregressive integrated moving average
exponential smoothing methods
forecasting
response surface methodology
wind power
autoregresyjna zintegrowana średnia ruchoma
metody wygładzania wykładniczego
prognozowanie
metodologia powierzchni odpowiedzi
energia wiatrowa
Opis:
Most of the existing statistical forecasting methods utilize the historical values of wind power to provide wind power generation prediction. However, several factors including wind speed, nacelle position, pitch angle, and ambient temperature can also be used to predict wind power generation. In this study, a wind farm including 6 turbines (capacity of 3.5 MW per turbine) with a height of 114 meters, 132-meter rotor diameter is considered. The time-series data is collected at 10-minute intervals from the SCADA system. One period from January 04th, 2021 to January 08th, 2021 measured from the wind turbine generator 06 is investigated. One period from January 01st, 2021 to January 31st, 2021 collected from the wind turbine generator 02 is investigated. Therefore, the primary objective of this paper is to propose a combined method for wind power generation forecasting. Firstly, response surface methodology is proposed as an alternative wind power forecasting method. This methodology can provide wind power prediction by considering the relationship between wind power and input factors. Secondly, the conventional statistical forecasting methods consisting of autoregressive integrated moving average and exponential smoothing methods are used to predict wind power time series. Thirdly, response surface methodology is combined with autoregressive integrated moving average or exponential smoothing methods in wind power forecasting. Finally, the two above periods are performed in order to demonstrate the efficiency of the combined methods in terms of mean absolute percent error and directional statistics in this study.
Źródło:
Archives of Electrical Engineering; 2021, 70, 4; 991-1009
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification method for power quality disturbances in distribution network based on transfer learning
Autorzy:
Heping, Peng
Wenxiong, Mo
Yong, Wang
Le, Luan
Zhong, Xu
Powiązania:
https://bibliotekanauki.pl/articles/2135730.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
disturbance identification
distribution network
multiple transfer learning
power quality
Opis:
For a higher classification accuracy of disturbance signals of power quality, a disturbance classification method for power quality based on gram angle field and multiple transfer learning is proposed in this paper. Firstly, the one-dimensional disturbance signal of power quality is transformed into a Gramian angular field (GAF) coded image by using the gram angle field, and then three ResNet networks are constructed. The disturbance signals with representative signal-to-noise ratios of 0 dB, 20 dB and 40 dB are selected as the input of the sub-model to train the three sub-models, respectively. During this period, the training weights of the sub-models are transferred in turn by using the method of multiple transfer learning. The pre-training weight of the latter model is inherited from the training weight of the previous model, and the weight processing methods of partial freezing and partial fine-tuning are adopted to ensure the optimal training effect of the model. Finally, the features of the three sub-models are fused to train the classifier with a full connection layer, and a disturbance classification model for power quality is obtained. The simulation results show that the method has higher classification accuracy and better anti-noise performance, and the proposed model has good robustness and generalization.
Źródło:
Archives of Electrical Engineering; 2022, 71, 3; 731--754
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A fault monitoring method for wind power generation system based on sliding mode observer
Autorzy:
Yu, Wenxin
Huang, Shao Dao
Jiang, Dan
Powiązania:
https://bibliotekanauki.pl/articles/141570.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
double-fed induction generator (DFIG)
sliding model observer (SMO)
stator voltage-oriented
Opis:
In this paper, a rotor current fault monitoring method is proposed based on a sliding mode observer. Firstly, the state-space model of the Double-Fed Induction Generator (DFIG) is constructed by vector transformation. Meanwhile, the stator voltage orientation vector control method is applied to decouple a stator and rotor currents, so as to obtain the correlation between the stator and rotor current. Furthermore, the mathematical model of stator voltage orientation is obtained. Then a state sliding mode observer (SMO) is established for the output current of the rotor of the DFIG. The stability and reachability of the system in a limited time is proved. Finally, the system state is determined by the residuals of the measured and estimated rotor currents. The simulation results show that the method proposed in this paper can effectively monitor the status: a normal state, voltage drop faults, short-circuit faults between windings, and rotor current sensor faults which have the advantages of fast response, high stability.
Źródło:
Archives of Electrical Engineering; 2020, 69, 3; 625-643
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Study of Susceptibility and Evaluation of Causes of Cracks Formation in Braze-Weld Filler Metal in Lap Joints Aluminum – Carbon Steel Made with Use of CMT Method and High Power Diode Laser
Autorzy:
Adamiak, M.
Wyględacz, B.
Czupryński, A.
Górka, J.
Powiązania:
https://bibliotekanauki.pl/articles/958197.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
braze-welding
intermetallic compound phase
high power diode laser
brazing
Opis:
In this article results of studies on cracks formation susceptibility in braze-welded joints of thin aluminum sheets and double-sided zinc galvanized steel sheets for car body parts made by laser brazing with high power diode laser ROFIN DL 020 and CMT MIG-brazing, with filler material in form of powder and wire accordingly, were presented. Optimal welding parameters were determined by visual acceptance criteria. On joints made with optimal parameters further examinations were carried. Results of macro- and microscopic metallographic examinations, structural roentgenography, EDS microanalysis and hardness tests were presented. Causes of brittle intermetallic Fe-Al phases formation in Al-matrix filler metal in dissimilar aluminum – zinc plated carbon steel joints were pointed.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 4; 2113-2123
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Designing Method of Compact n-to-2ⁿ Decoders
Autorzy:
Brzozowski, I.
Zachara, Ł.
Kos, A.
Powiązania:
https://bibliotekanauki.pl/articles/226116.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
decoder
address decoder
standard cell
layouts design
CMOS technology
power dissipation
power consumption
delay
Opis:
What decoder is, everyone knows. The paper presents fast and efficient method of layouts design of n-to-2ⁿ -lines decoders. Two scenarios of layout arrangement are proposed and described. Based on a few building blocks only, especially prepared, and appropriate procedure of their placement, a decoder of any size can be build. Layouts of all needed fundamental blocks were designed in CMOS technology, as standard library. Moreover, some important parameters, such area, power dissipation and delay, were assessed and compared for decoders designed with proposed method and traditional. Power consumption were considered under extended model, which takes into account changes of input vectors, not only switching activity factor. All designs were done in UMC 180 CMOS technology.
Źródło:
International Journal of Electronics and Telecommunications; 2013, 59, 4; 405-413
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
GA based optimal planning of VAR sources using Fast Voltage Stability Index method
Autorzy:
Bhattacharyya, B.
Rani, S.
Vais, I. R.
Bharti, P. I.
Powiązania:
https://bibliotekanauki.pl/articles/140784.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active power loss
FVSI method
genetic algorithm
operating cost
reactive power planning
weak nodes
Opis:
This paper presents a novel approach for reactive power planning of a connected power network. Reactive power planning is nothing but the optimal usage of all reactive power sources i.e., transformer tap setting arrangements, reactive generations of generators and shunt VAR compensators installed at weak nodes. Shunt VAR compensator placement positions are determined by a FVSI (Fast Voltage Stability Index) method. Optimal setting of all reactive power reserves are determined by a GA (genetic algorithm) based optimization method. The effectiveness of the detection of the weak nodes by the FVSI method is validated by comparing the result with two other wellknown methods of weak node detection like Modal analysis and the L-index method. Finally, FVSI based allocation of VAR sources emerges as the most suitable method for reactive power planning.
Źródło:
Archives of Electrical Engineering; 2016, 65, 4; 789-802
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A current decomposition-based method for computationally efficient implementation of power resolution meters in non-sinusoidal single-phase systems
Autorzy:
Balci, M. E.
Hocaoglu, M. H.
Powiązania:
https://bibliotekanauki.pl/articles/220775.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power resolutions
non-sinusoidal conditions
single-phase systems
power meter
Opis:
For non-sinusoidal single-phase systems, the classical apparent power has been divided into various components using different techniques. These power resolutions generally aim at to provide a tool for the accurate determination of the maximum power factor achievable with a passive compensator and to measure the load's nonlinearity degree. This paper presents a current decomposition-based methodology that can be employed for computationally efficient implementation of the widely recognized non-sinusoidal power resolutions. The proposed measurement method and the original expressions of the power resolutions are comparatively evaluated by considering their computational complexity. The results show that the proposed method has a significant advantage in terms of computational efficiency for the simultaneous measurements of the powers when compared with the original expressions. Finally, in this paper, a PC-based power meter is developed using the proposed measurement method via the LabVIEW programme.
Źródło:
Metrology and Measurement Systems; 2013, 20, 2; 263-274
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessing system impedance based on data regrouping
Autorzy:
Xu, Shuangting
Xiao, Xianyong
Wang, Yang
Wu, Jun
Powiązania:
https://bibliotekanauki.pl/articles/1848954.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
system impedance
passive method
Thevenin equivalent
power system
Opis:
In recent years, assessing supply system impedance has become crucial due to the concerns on power quality and the proliferation of distributed generators. In this paper, a novel method is shown for passive measurement of system impedances using the gapless waveform data collected by a portable power quality monitoring device. This method improves the overall measurement accuracy through data regrouping. Compared with the traditional methods that use the consecutive measurement data directly, the proposed method regroups the data to find better candidates with less flotation on the system side. Simulation studies and extensive field tests have been conducted to verify the effectiveness of the proposed method. The results indicate that the proposed method can serve as a useful tool for impedance measurement tasks performed by utility companies.
Źródło:
Metrology and Measurement Systems; 2021, 28, 1; 191-208
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessing system impedance based on data regrouping
Autorzy:
Xu, Shuangting
Xiao, Xianyong
Wang, Yang
Wu, Jun
Powiązania:
https://bibliotekanauki.pl/articles/1848965.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
system impedance
passive method
Thevenin equivalent
power system
Opis:
In recent years, assessing supply system impedance has become crucial due to the concerns on power quality and the proliferation of distributed generators. In this paper, a novel method is shown for passive measurement of system impedances using the gapless waveform data collected by a portable power quality monitoring device. This method improves the overall measurement accuracy through data regrouping. Compared with the traditional methods that use the consecutive measurement data directly, the proposed method regroups the data to find better candidates with less flotation on the system side. Simulation studies and extensive field tests have been conducted to verify the effectiveness of the proposed method. The results indicate that the proposed method can serve as a useful tool for impedance measurement tasks performed by utility companies.
Źródło:
Metrology and Measurement Systems; 2021, 28, 1; 191-208
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Fast Classification Method of Faults in Power Electronic Circuits Based on Support Vector Machines
Autorzy:
Cui, J.
Shi, G.
Gong, C.
Powiązania:
https://bibliotekanauki.pl/articles/220922.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power electronics
fault diagnosis
wavelet transforms
support vector machines
directed acyclic graph
nearest neighbours
Opis:
Fault detection and location are important and front-end tasks in assuring the reliability of power electronic circuits. In essence, both tasks can be considered as the classification problem. This paper presents a fast fault classification method for power electronic circuits by using the support vector machine (SVM) as a classifier and the wavelet transform as a feature extraction technique. Using one-against-rest SVM and one-against-one SVM are two general approaches to fault classification in power electronic circuits. However, these methods have a high computational complexity, therefore in this design we employ a directed acyclic graph (DAG) SVM to implement the fault classification. The DAG SVM is close to the one-against-one SVM regarding its classification performance, but it is much faster. Moreover, in the presented approach, the DAG SVM is improved by introducing the method of Knearest neighbours to reduce some computations, so that the classification time can be further reduced. A rectifier and an inverter are demonstrated to prove effectiveness of the presented design.
Źródło:
Metrology and Measurement Systems; 2017, 24, 4; 701-720
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computationally efficient method of simulation of an electric drive impact on the power grid
Autorzy:
Beniak, R.
Gardecki, A.
Powiązania:
https://bibliotekanauki.pl/articles/141226.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
electric drive
converter system model
power grid
Opis:
This paper presents a computationally efficient method for modelling an impact of the converter drive on the power grid. The formalized variable structure method (FVSM) allows for comprehensive studies of the effect on the power grid and examining the relation between this effect and the number of drive and feeding line parameters. In order to obtain a comprehensive model along with the model of the power grid, the parameters that are applied originate from a drive of a coal-fired power station. These parameters have been determined based on assessment and estimation. The estimation process was conducted with the aid of a model that allows for the commutation of power electronic elements. The authors confirmed that the model was correct by comparing empirical and theoretical voltage and current waveforms. Harmonic content of the voltage and current in the power grid which feeds the drive are considered to be the measure of the converter drive impact on the power grid. The standard method for the reduction of a harmonic content in the voltage and current involves the application of line reactors and distribution or converter transformers. As an example, the authors determine the impact of the drive on the power grid with respect to the adopted parameters of the line reactor. This example presents FVSM abilities with regard to simulation of complex systems that contain power grid components and converter drives.
Źródło:
Archives of Electrical Engineering; 2013, 62, 1; 77-90
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficient cloud-based digital-physical testing method for feeder automation system in electrical power distribution network
Autorzy:
Chen, Guoyan
Mo, Wenxiong
Wang, Hongbin
Tang, Jinrui
Bian, Xinhao
Powiązania:
https://bibliotekanauki.pl/articles/140469.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cloud simulation
digital-physical testing method
feeder automation
feeder terminal unit
power distribution system
Opis:
A feeder automation (FA) system is usually used by electricity utilities to improve power supply reliability. The FA system was realized by the coordinated control of feeder terminal units (FTUs) in the electrical power distribution network. Existing FA testing technologies can only test basic functions of FTUs, while the coordinated control function among several FTUs during the self-healing process cannot be tested and evaluated. In this paper, a novel cloud-based digital-physical testing method is proposed and discussed for coordinated control capacity test of the FTUs in the distribution network. The coordinated control principle of the FTUs in the local-reclosing FA system is introduced firstly and then, the scheme of the proposed cloud-based digital-physical FA testing method is proposed and discussed. The theoretical action sequences of the FTUs consisting of the FTU under test and the FTUs installed in the same feeder are analyzed and illustrated. The theoretical action sequences are compared with the test results obtained by the realized cloud-based simulation platform and the digital-physical hybrid communication interaction. The coordinated control capacity of the FTUs can be evaluated by the comparative result. Experimental verification shows that the FA function can be tested efficiently and accurately based on our proposed method in the power distribution system inspection.
Źródło:
Archives of Electrical Engineering; 2020, 69, 3; 545-559
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inter-harmonic parameter identification method based on transform with local maximum spectrum
Autorzy:
Sun, Lin
Song, Jing
Jin, Yan
Powiązania:
https://bibliotekanauki.pl/articles/2042793.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
inter-harmonic
parameter identification
power system
synchrosqueezed transform
time-frequency analysis
Opis:
In order to improve the detection accuracy of harmonics/inter-harmonics in power systems, a new method of harmonic/inter-harmonic detection based on synchrosqueezed transform and the Hilbert operator based on local spectrum maximum is proposed. Firstly, the spectrum of inter-harmonic signals is obtained through short-time Fourier transform, and the local maximum value of the spectrum in the frequency direction is detected. Then, based on the maximum frequency of the spectrum, a new frequency redistribution operator and synchronous extraction operator are constructed. It combines the operators with ridge detection for the decomposition of harmonic/inter-harmonic signals, so as to obtain a series of intrinsic mode function (IMF) components. Finally, the instantaneous amplitude and frequency of the IMF components is obtained by using the Hilbert operator. Meanwhile, according to the instantaneous frequency mutation point in the spectrum, the starting and ending time of transient harmonics/inter-harmonics is located accurately. Based on a low signal-to-noise ratio (SNR), the wavelet packet method (WP), Hilbert Marginal Spectrum method (HMS), synchrosqueezing wavelet transform method (SST), the Hybrid SST method (HSST), enhanced empirical wavelet transform (EEWT) and the proposed method are used to identify the harmonic/inter-harmonic parameters, respectively. The experimental results show that the proposed LMSST method can effectively separate the steady-state and transient harmonic/inter-harmonic signals, and has higher detection accuracy and better noise robustness.
Źródło:
Archives of Electrical Engineering; 2022, 71, 1; 189-209
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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