Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: fringing-effect factor

Sortuj według:

Ogranicz wyniki do:

Reduction of Fringing-Effect in Inductors by Quasi-Distributed-Gap Method

Kasikowski Rafał

Measurement Automation Monitoring

2019

Vol. 65, No. 2

48--51

The fringing-field phenomenon can have a significant impact on the key performance parameters of magnetic components with an air gap. The fringing magnetic flux at the air gap has an effect on a component’s inductance, power loss and temperature distribution in copper windings. The induced excess eddy currents in the windings due to the fringing effect cause localized heating and reduce the overall efficiency of power conversion. This effect can be analysed by infra-red thermography to demonstrate the potential hazards of designing magnetic components with an air gap. Design engineers are frequently forced to design around the problem by employing a number of available techniques. The quasi-distributed-gap technique combats the issue at the origin as it essentially constrains the fringing magnetic flux at the downsized air gaps to their immediate vicinity. The selection of the length of the individual air gaps as well as their placement is not straightforward, as the phenomenon is a function of the air gap length and geometry. The resulting inductance of the component has to be the same or at least comparable to the original value in order to maintain the operating conditions of the application which the component is part of. This paper examines the effects of splitting a discrete air gap on the electromagnetic and thermal properties of inductors and presents a method to aid the design of quasi-distributed-gap inductors based on finite-element simulations as well as measurements. An analytic expression, which closely approximates the required length of quasi-distributed gaps, is developed.

Impact of the fringing effect on temperature distribution in windings and physical properties of toroidal ferrite inductors with a dual air gap

Kasikowski R.

Measurement Automation Monitoring

2017

Vol. 63, No. 4

135--138

This paper examines the impact of the fringing field at an air gap on the temperature distribution, power loss and other properties of toroidal ferrite inductors with a dual air gap. An air gap constitutes a discontinuity in a magnetic path of an inductor, representing significantly greater reluctance to magnetic flux than that of a ferrite core. The magnetic flux does not cross the air gap in straight lines, but fringes out into the surrounding medium causing electromagnetic interactions with the copper winding enclosing the air gap. This phenomenon is a function of the air gap and the windings geometry as well as the operating frequency. The net effect of the fringing flux is to shorten the gap and to decrease the effective reluctance of the magnetic path. Consequently, coils wound on magnetic cores with a relatively large single air gap, thus with an exacerbated fringing effect, exhibit higher inductance than those with multiple, quasi-distributed or distributed air gaps of the same effective length as the discrete one. The presented research investigates the effects of splitting a discrete air gap on the electromagnetic and thermal properties of toroidal ferrite inductors.