AM Modulation Signal Estimation Allowing Further Research on Sources of Voltage Fluctuations

Kuwałek, Piotr

doi:10.1109/tie.2019.2935978

Cited by 23 publications

(7 citation statements)

References 35 publications

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“…Let r i and θ i be the phase information of oral English pronunciation sequence, respectively, and the modulation signal [21] of oral English sequence was obtained as follows:…”

Section: Sequence Matching In Oral Englishmentioning

confidence: 99%

Design of Automatic Scoring System for Oral English Test Based on Sequence Matching and Big Data Analysis

Ping

Hua

Tsai

2021

Discrete Dynamics in Nature and Society

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With the application of an automatic scoring system to all kinds of oral English tests at all levels, the efficiency of test implementation has been greatly improved. The traditional speech signal processing method only focuses on the extraction of scoring features, which could not ensure the accuracy of the scoring algorithm. Aiming at the reliability of the automatic scoring system, based on the principle of sequence matching, this paper adopts the spoken speech feature extraction method to extract the features of spoken English test pronunciation and establishes a dynamic optimized spoken English pronunciation signal model based on sequence matching, which could maintain good dynamic selection and clustering ability in a strong interference environment. According to the comprehensive experiment, the automatic scoring result of the system is much higher than that of the traditional method, which greatly improves the recognition ability of oral pronunciation, solves the difference between the automatic scoring of the system and the manual scoring, and promotes the computer automatic scoring system to replace or partially replace the manual marking.

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“…Let r i and θ i be the phase information of oral English pronunciation sequence, respectively, and the modulation signal [21] of oral English sequence was obtained as follows:…”

Section: Sequence Matching In Oral Englishmentioning

confidence: 99%

Design of Automatic Scoring System for Oral English Test Based on Sequence Matching and Big Data Analysis

Ping

Hua

Tsai

2021

Discrete Dynamics in Nature and Society

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“…Although the accuracy of algorithms recreating voltage changes in relation to other algorithms available in the literature has been improved, it is still limited to voltage fluctuations whose source does not change its operating state with a frequency greater than 20 Hz. Improvement of individual algorithms that would allow the research on all sources of voltage fluctuations is further studies of the authors, e.g., creation of a new method for estimating a modulating signal with a higher frequency than the carrier [28]; or creating a wireless measuring and recording device enabling measurement of the average value and standard deviation of the speed of voltage changes [29]. It is expected that the obtained results would allow for automatic identification and analysis of voltage fluctuation sources in the power grid with Fig.…”

Section: Resultsmentioning

confidence: 99%

Recreation of Voltage Fluctuation Using Basic Parameters Measured in the Power Grid

Kuwałek

Jesko

2020

J. Electr. Eng. Technol.

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The article presents the preliminary research results on recreating the envelope using the basic parameters measured in the power grid. Six novel algorithms were presented. The quality of proposed algorithms was verified based on the short-term flicker indicator P st and instantaneous flicker P inst. Probability theory was used in some of the presented algorithms, considering the random operation of real sources of voltage fluctuations. At the beginning of the article an introduction containing the essence of the discussed issues is presented. Next, description of the basic measured parameters in the power grid are presented, being the input data of the tested algorithms. The subsequent part presents the operation of individual algorithms, the correctness of which was verified by laboratory studies and numerical simulations. In addition, the operation of the proposed algorithms for real measurements made for the wastewater pumping station supply circuit is also presented. The metrological interpretation of the results obtained from the numerical simulation and experimental research is discussed, and the conclusions are presented.

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“…In each iteration, first, the real AM modulating signal is estimated using carrier signal estimation according to the algorithm presented in Figure 2. A detailed description of the selected AM demodulation method, verification of its correctness, and its limitations are presented in [36]. In the next step, the estimated voltage modulating AM signal is decomposed using the enhanced empirical wavelet transform (EEWT) into N components.…”

Section: Algorithm For Selective Identification and Localization Of Voltage Fluctuation Sourcesmentioning

confidence: 99%

Selective Identification and Localization of Voltage Fluctuation Sources in Power Grids

Kuwałek¹

2021

Energies

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The current study presents a novel approach to the selective identification and localization of voltage fluctuation sources in power grids, considering individual disturbing loads changing their state with a frequency of up to 150 Hz. The implementation of the proposed approach in the existing infrastructure of smart metering allows for the identification and localization of the individual sources of disturbances in real time. The proposed approach first performs the estimation of the modulation signal using a carrier signal estimator, which allows for a modulation signal with a frequency greater than the power frequency to be estimated. In the next step, the estimated modulating signal is decomposed into component signals associated with individual sources of voltage fluctuations using an enhanced empirical wavelet transform. In the last step, a statistical evaluation of the propagation of component signals with a comparable fundamental frequency is performed, which allows for the supply point of a particular disturbing load to be determined. The proposed approach is verified in numerical simulation studies using MATLAB/SIMULINK and in experimental studies carried out in a real low-voltage power grid. The research carried out shows that the proposed approach allows for the selective identification and localization of voltage fluctuation sources changing their state with a frequency of up to 150 Hz, unlike other methods currently used in practice.

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AM Modulation Signal Estimation Allowing Further Research on Sources of Voltage Fluctuations

Cited by 23 publications

References 35 publications

Design of Automatic Scoring System for Oral English Test Based on Sequence Matching and Big Data Analysis

Design of Automatic Scoring System for Oral English Test Based on Sequence Matching and Big Data Analysis

Recreation of Voltage Fluctuation Using Basic Parameters Measured in the Power Grid

Selective Identification and Localization of Voltage Fluctuation Sources in Power Grids

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