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1

Controlling magnetic inductance by air-gap configuration in power electronics applications

Kasikowski Rafal

Archives of Electrical Engineering

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2023

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Vol. 72, nr 3

677-695

EN

Gapped magnetic components are inherent to applications where conversion of power would force magnetic flux density beyond the saturation point of magnetic materials. A physical discontinuity in a magnetic path, which an air gap represents, signifies a drastic change in its reluctance to magnetic flux. This gives rise to a phenomenon referred to as the fringing effect, which impacts the performance of magnetic components. The fringing flux also affects the physical properties of magnetic components, such as magnetic reluctance and inductance. Since inductance of gapped magnetic components is a function of the size of the air gap, a relatively simple change to the configuration of the air gap or splitting a single gap into a plurality of gaps entails, frequently, a radical change to the magnetic circuit of the component. This paper examines the way the air-gap configuration affects the distribution of the fringing flux and, by extension, magnetic reluctance and inductance. A method to aid the design of multigap inductors is presented based on 3-D electromagnetic modelling as well as measurements. An analytic expression, which closely approximates the required length of quasi-distributed gaps substituting a single gap, is developed.

2

Design Optimization of QFP Structure for over 8Gbps Package Applications

Sun H., Cai Z., Wu J., Shi L., Sun L.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

284--289

EN

A 8Gbps packaging solution that uses low-cost quad flat pack (QFP) technology is presented. Since such a high speed is beyond the reach of traditional QFP package structure, a new design methodology with coplanar transmission line structure built into the lead frame has been developed. Due to the complexity level in QFP structure, each interconnect segment is accurately modelled in 3D model by utilizing the industry leading advance software tool, ANSYS HFSS. S-parameter, Time Domain Reflectometry (TDR) and Eye Diagram are used to help in understanding the contributing to the optimized QFP structure. The analysis results indicate that the optimized QFP structure can successfully achieve over 8Gbps single-end signal transmission.

PL

W artykule przedstawiono metodę zmiany struktury QFP na potrzeby przesyłu z prędkością 8Gbps. W celu analizy działania, stworzono model struktury o bardzo wysokiej precyzji, przy wykorzystaniu programów ANSYS HFSS. S-parameter, Time Domain Reflectometry (TDR) oraz Eye Diagram. Analiza wyników badań wykazuje, że wprowadzona optymalizacja pozwala na osiągnięcie założonej prędkości przesyłu danych.

3

The description and modeling of dynamic electromagnetic phenomena in high-Tc superconductors

Lebioda M.

Zeszyty Naukowe. Elektryka / Politechnika Łódzka

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2006

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z. 109

63-72

EN

The analysis of the magnetic field penetration process in the high-Tc bulk superconductor and the change of distribution of shielding currents and local superconductor parameters connected with this process have been presented in the thesis. The non-linear dynamic model built on the basis of the equation of the magnetic field diffusion is presented in this paper.

PL

Zasadniczym celem pracy jest analiza procesu wnikania i rozkładu pola magnetycznego w masywnych nadprzewodnikach wysokotemperaturowych. Przeprowadzone rozważania dotyczą pól quasi-statycznych oraz pól o częstotliwości zmian zbliżonej i przekraczającej częstotliwość techniczną. Celem badań jest identyfikacja i analiza procesów związanych z przemieszczaniem strumienia magnetycznego w nadprzewodniku oraz analiza wpływu dynamiki ruchu na zmianę parametrów nadprzewodnika. Dynamicznym zmianom zewnętrznego pola magnetycznego towarzyszy zmiana przestrzennego rozk ł adu pola magnetycznego i prądu w nadprzewodniku. W pracy wykorzystano nieliniowy, dynamiczny model zbudowany w oparciu o równania dyfuzji pola magnetycznego.

4

Study of geological sedimentary structures of Mekong river banks by ground penetrating radar: forecasting avulsion-prone zones

Nguyen V.G., Ziętek J., Nguyen B.D., Karczewski J., Gołębiowski T.

Acta Geophysica Polonica

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2005

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Vol. 53, nr 2

167-181

EN

Ground Penetrating Radar (GPR) is a high-resolution near-surface geophysical technique which employs radio waves to map structures and features buried in the ground (or in man-made structures). The results of GPR survey can also be processed and interpreted to obtain physical parameters of rock formation such as dielectric permittivity, electrical conductivity, velocity of electromagnetic waves, attenuation, and other. The georadar method provides continuous graphic format for recorded data which permits rapid semi-quantitative in-field analysis. The paper presents results of a successful application of a Canadian instrument Pulse EKKO 100A for the near-surface geological sedimentary structure investigation in Vietnam. The interfaces, fractures, weakness zones etc. in the geological formation on the Mekong river banks were located and interpreted by georadar cross-sections. The paper presents also results of modelling of electromagnetic field distribution by means of Finite Difference Time Domain method for the Khach San profile at the Mekong river banks.