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An adaptive neuro-fuzzy based methodology for harmonic analysis of a power transformer

Urooj Shabana, Amir Mohammad, Khan Aiman, Tariq Mohd

Journal of Power Technologies

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2021

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Vol. 101, nr 1

1--10

EN

The interfering nature of harmonics always causes various power quality issues that impacts on both efficiency, and expected transformer life. Optimal analysis of the three-phase core power transformers using harmonic spectrum can limit these power quality issues. This paper designs the Adaptive Neuro-Fuzzy Inference System (ANFIS) based model for the estimation of losses. Further optimal parameters selection of three-phase power transformer using iron and ferrite core materials. This paper demonstrates factors that deteriorate the power quality, responsible for harmonics distortions and inefficiency in power transformers. The proposed ANFIS based analysis provides an optimal solution to harmonic reduction and improves overall efficiency. Also, providing a comparative study of various core parameters that will be suitable for a three-phase core transformer. The proposed parameters are demonstrated for improving the overall transformer efficiency using iron and ferrite core material. ANSYS Maxwell simulation estimates the Total Harmonic Distortion (THD) and enhances THD in contributing to the optimal core material. The design of a three-phase power transformer and the performance evaluation of the proposed methodology performed in MATLAB simulation environment.

2

Estimation of discharge correction factor of modified Parshall flume using ANFIS and ANN

Saran D., Tiwari N. K.

Archives of Materials Science and Engineering

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2020

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Vol. 105, nr 1

17--30

EN

Purpose: To evaluate and compare the capability of ANFIS (Adaptive Neuro-Fuzzy-Inference System), ANN (Artificial Neural Network), and MNLR (Multiple Non-linear Regression) techniques in the estimation and formulation of Discharge Correction Factor (Cd) of modified Parshall flumes as based on linear relations and errors between input and output data. Design/methodology/approach: Acknowledging the necessity of further research in this field, experiments were conducted in the Hydraulics Laboratory of Civil Engineering Department, National Institute of Technology, Kurukshetra, India. The Parshall flume characteristics, associated longitudinal slopes and the discharge passing through the flume were varied. Consequent water depths at specific points in Parshall flumes were noted and the values of Cd were computed. In this manner, a data set of 128 observations was acquired. This was bifurcated arbitrarily into a training dataset consisting of 88 observations and a testing dataset consisting of 40 observations. Models developed using the training dataset were checked on the testing dataset for comparison of the performance of each predictive model. Further, an empirical relationship was formulated establishing Cd as a function of flume characteristics, longitudinal slope, and water depth at specific points using the MNLR technique. Moreover, Cd was estimated using soft computing tools; ANFIS and ANN. Finally, a sensitivity analysis was done to find out the flume variable having the greatest influence on the estimation of Cd. Findings: The predictive accuracy of the ANN-based model was found to be better than the model developed using ANFIS, followed by the model developed using the MNLR technique. Further, sensitivity analysis results indicated that primary depth reading (Ha) as input parameter has the greatest influence on the prediction capability of the developed model. Research limitations/implications: Since the soft computing models are data based learning, hence the prediction capability of these models may dwindle if data is selected beyond the current data range, which is based on the experiments conducted under specific conditions. Further, since the present study has faced time and facility constraints, hence there is still a huge scope of research in this field. Different lateral slopes, combined lateral- longitudinal slopes, and more modified Parshall flume models of larger sizes can be added to increase the versatility of the current research. Practical implications: Cd of modified Parshall flumes can be predicted using the ANN- based prediction model more accurately as compared to other considered techniques. Originality/value: The comparative analysis of prediction models, as well as the formulation of relation, has been conducted in this study. In all the previous works, little to no soft computing techniques have been applied for the analysis of Parshall flumes. Even the regression techniques have been applied only on Parshall flumes of standard sizes. However, this paper includes not only Parshall flume of standard size but also a modified Parshall flume in its pursuit of predicting Cd with the help of ANN and ANFIS based prediction models along with MNLR technique.

3

Zastosowanie ANFIS w analizie wyników badań gruntów

Daniszewska E

Budownictwo i Architektura

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2014

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Vol. 13, nr 2

7--15

PL

Adaptacyjny system wnioskowania neuronowo-rozmytego ANFIS (Adaptive Neuro-Fuzzy Inference System) w programie Matlab posłużył modelowaniu i określaniu relacji między prędkością ścinania a parametrami wytrzymałościowymi gruntu. Sprawdzono możliwości i umiejętności narzędzia ANFIS w interpretacji wyników badań trójosiowego ściskania iłów pobranych z okolic Olsztyna. Model neuronowo-rozmyty został zbudowany na podstawie zbioru wartości, którymi dysponowano po szeregu badań eksperymentalnych, łącznie z wartościami parametrów wytrzymałościowych gruntu na ścinanie. Baza danych wykorzystana do modelowania neuronowo-rozmytego składa się z 6 różnych parametrów gruntowych dla każdej z 12 prędkości ścinania stosowanych podczas badań trójosiowych. Umiejętność uczenia zweryfikowano na bazie danych testowych - model neuronowo-rozmyty zbudowany został z zestawów szkoleniowych, a dokładność została zweryfikowana przez zestawy testów, z którymi model miał do czynienia po raz pierwszy. Wyniki z modelu ANFIS nie odbiegały znacznie od tych, które zostały uzyskane bezpośrednio z badań fizycznych. System ANFIS okazał się narzędziem niezwykle uniwersalnym i nieskomplikowanym w obsłudze. Pozwolił uwzględnić wieloaspektowość wzajemnych relacji parametrów gruntowych.

EN

The article was analyzed in order to test applicability and capability of the ANFIS tool used for interpretation of results of triaxial shear tests on loamy soils sampled near Olsztyn. The ANFIS system in the Matlab software programme was used to model and determine relationships between the shear stress and soil resistance parameters in a triaxial shear test apparatus. It has been demonstrated that the achieved shear strength parameters are significantly affected by the variables tested during the triaxial experiments and physical parameters of a given soil sample, but also by the loading increment rate during the tests. It is extremely important to adjust the rate of loading during a test according to the preliminary characterization of a tested ground sample so as to have some control over the obtained ground strength parameters. The neuro-fuzzy model has been constructed based on a set of values obtained after a series of experimental tests, including values of ground shear strength parameters. The database used for the neuro-fuzzy modelling consisted of 6 different ground parameters for each of the 12 shear stress rates applied during the triaxial tests. The learnability was verified on a database composed of the test results – a neuro-fuzzy model was built from learning sets and its accuracy was verified by sets of tests to which the model was applied for the first time. The results obtained from the ANFIS model did not diverge substantially from the ones obtained directly by performing the physical tests. The ANFIS proved to be highly universal and easy to operate. It accounted for the multi-faceted nature of interrelationships between ground parameters.