Wyniki wyszukiwania - BazTech

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Selected Nature-Inspired Algorithms in Function of PM Synchronous Motor Cogging Torque Minimisation

Cvetkovski Goga Vladimir, Petkovska Lidija

Power Electronics and Drives

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2021

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Vol. 6 (41)

204--217

EN

Both permanent magnet brushless DC motors and permanent magnet synchronous motors have attracted wide attention and are increasingly used in industrial high-performance applications in recent years. Those motors are known for their good electrical, magnetic and performance characteristics, but there is one parameter known as cogging torque that has a negative influence on the performance characteristics of the motor. This pulsating torque is generated as a result of the interaction between the stator teeth and the permanent magnets. The minimisation of the ripple of this torque in those permanent magnet motors is of great importance and is generally achieved by a special motor design which in the design process involves a variety of many geometrical motor parameters. In this research work, a novel approach will be introduced where two different nature-inspired algorithms, such as genetic algorithm (GA) and cuckoo search (CS) algorithm are used as an optimisation tool, in which the defined equation for the maximum value of the cogging torque is applied as an objective function. Therefore, a proper mathematical presentation of the maximum value of the cogging torque for the analysed synchronous motor is developed and implemented in the research work. For a detailed analysis of the three different motor models, the initial motor and the two optimised motor models are modelled and analysed using a finite element method approach. The cogging torque is analytically and numerically calculated and the results for all the models are presented.

2

Laboratory investigations of diclofenac migration in saturated porous media - a case study

Okońska Monika, Marciniak Marek, Zembrzuska Joanna, Kaczmarek Mariusz

Geologos

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2019

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Vol. 25, No. 3

213--223

EN

At present, concentrations of pharmaceuticals in surface and ground waters are low; however, even low concentrations of certain substances may prove very harmful. One of such pharmaceutical drugs is diclofenac, a popular non-steroidal anti-inflammatory drug (NSAID). For this reason, it is important to determine its mobility in groundwater and to estimate parameters of migration. Authors conducted column tests for two porous media: an artificial one, consisting of glass granules, and a natural one, i.e., sandur sand obtained from a site north of the city of Poznań (Poland). During the test, impulse breakthrough curves of chloride ions and diclofenac were recorded. The results were used to identify a specific sorption model and to determine values of migration parameters. Solutions of the inverse problem using optimisation methods and of equations of mathematical migration models were carried out in a MATLAB environment. Based on test results, the mobility of diclofenac is shown to be very high and comparable to that of chloride ions. The tests also revealed a slight and irreversible sorption of diclofenac on grains of both porous media.

3

Prerequisites for the modelling of empty container supply chains

Kuźmicz K. A., Pesch E.

Engineering Management in Production and Services

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2017

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Vol. 9, no. 3

28--36

EN

Containerisation of freight transport significantly facilitates the flow of traded goods between remote destinations. The most important container transport routes link Asia with North America and Europe. The seasonality and imbalance of trade are the main factors giving rise to problems related to empty container repositioning. The aim of this paper is to develop a concept of empty container supply chains and formulate prerequisites for its modelling in the search for the optimal solution with the help of linear programming and mixed integer programming methods. This paper indicates causes of the empty container relocation problem based on the literature analysis with a special focus on the Eurasian transportation route. Also, it provides a concept of empty container supply chain, prerequisites for its modelling and examples of container supply chains modelling presented in the literature. The main results of the paper include conceptualisation of an empty container supply chain and suggested modelling prerequisites. The paper contributes to research in the field of supply chain management and optimisation of transportation.

4

Inverse Problem of Textile Material Design at Low Temperature Solved by a Hybrid Stochastic Algorithm

Weng M, Xu D, Zhou X

Fibres & Textiles in Eastern Europe

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2015

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Vol. 23, no. 2 (110)

40—43

EN

The inverse problem of textile material design (IPTMD) aims to determine textile materials with optimum thermal conductivities for the thickness designed in terms of the thermal comfort requirements of the wearer. In this paper, an IPTMD is presented on the basis of the physical nature of steady heat and moisture transfer in a human body-clothing-environment system. A globally convergent algorithm, the modified particle collision algorithm (MPCA), is proposed and its validity is verified. The MPCA is applied to solve the IPTMD for single-layer textile materials at low temperature. Numerical simulation results of the IPTMD proved the suitability of the IPTMD and effectiveness of the MPCA in solving complex global optimisation problems. The encouraging results indicate that the modelling method above and optimisation algorithm can be used for further applications.

PL

Problem inwersyjny projektowania materiałów włókienniczych ma na celu określenie materiałów włókienniczych z optymalną przewodnością cieplną dla grubości zaprojektowanej z uwzględnieniem komfortu termicznego i wygody użytkownika. W pracy przedstawiono problem na podstawie stałego przepływu ciepła i wilgotności pomiędzy ciałem człowieka, odzieżą a środowiskiem zewnętrznym. Zaprezentowano i zweryfikowano prawidłowość algorytmu zbieżnego, algorytmu zderzenia cząstek modyfikowanych, który jest stosowany w celu rozwiązania problemu dla jednowarstwowych materiałów włókienniczych w niskich temperaturach. Wyniki symulacji numerycznych problemu dowodzą jego przydatności i skuteczności algorytmu w rozwiązywaniu złożonych problemów optymalizacji. Zachęcające rezultaty wskazują, że powyższy sposób modelowania i algorytm optymalizacji mogą być używane do różnych zastosowań.

5

Optymalizacja cech dynamicznych eliminatora drgań układu napędowego

Mężyk A., Świtoński E.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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1998

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z. 7

237-242

PL

W pracy przedstawiono algorytm doboru parametrów dynamicznego eliminatora drgań , z wykorzystaniem metod optymalizacji . Optymalizację parametrów dynamicznych układu przeprowadzono metodą sekwencyjnego programowania liniowego . Celem prowadzonych badań była minimalizacja współczynnika wzmocnienia pierwszej masy układu.

EN

An algorithm of selection of dynamic parameters of vibration eliminator has been presented . The algorithm has been elaborated on basis of optimisation method . The optimisation process has been carried out by Sequential Linear Prograrmning method . The objective function describing amplification factor for the first element of the system has been assumed.