Selection of the appropriate winding setup in planar inductors with parallel windings

The use of parallel windings in high frequency planar inductors is a common practice. Since the planar technology, commonly PCB layers, limits the maximum layer thickness, the use of parallel windings is usually required in order to reduce the current density and losses. The distribution of the current through each parallel winding depends on the winding positioning and the frequency effects. This effect is especially important in gapped inductors, because the energy stored in the gap region determines the current distribution through the windings. Therefore, the winding positioning is a critical task in order to obtain a balanced current distribution through all the parallel winding

Automatized connection of the layers of planar transformers with parallel windings to improve the component behavior

Transformers with parallel windings are commonly used to reduce the losses in the windings. Windings losses depend on the winding positioning and the frequency effects because each winding affects the current sharing of itself and the neighboring windings. In this paper a methodology for determining the connections of the parallel windings that reduces the power losses (and temperature) in the windings of multi-winding transformers is presented. Other applications of the method, such as balanced current sharing and voltage drop reduction are also explored. In this paper a methodology for determining the connections of the parallel windings that reduces the power losses (and temperature) in the windings of multi-winding transformers is presented. Other applications of the method, such as balanced current sharing and voltage drop reduction are also explored

A simplified capacitive model for center-tapped multi-windings transformers

A simplified capacitive model for transformers with center-tapped windings has been developed. A Finite Element Analysis (FEA) tool is used to compute the electric energy in the windings of the transformer in order to obtain the required parameters of the model. Due to its reduced number of elements it can be easily used to model the capacitive effects in symmetrical (center-tapped) multi-winding magnetic components such as transformers for Push-Pull (PP), Half-Bridge (HB) and Full-Bridge (FB) applications. Some experimental results are compared with simulations

Power losses calculations in windings of gapped magnetic components

A model is proposed for the calculation of the winding losses at the beginning of the design process of high frequency transformers and inductors. Although this kind of losses have been subject of investigation for years, their analytical calculation in gapped components is still limited, and the use of numerical analysis tools, such as finite elements analysis (FEA) tools, are commonly needed for winding characterization. A general 2-D equivalent analytical model for windings losses calculation in gapped magnetic components that shows very good results compared with FEA calculation is presented. The model can be integrated in design and optimization tools in order to evaluate the influence of the gap on the windings at the very early stages of the design process

Simple analytical approach for the calculation of winding resistance in gapped magnetic components

The Dowell expression is the most commonly used method for the analytic calculation of the equivalent resistance in windings of magnetic components. Although this method represents a fast and useful tool to calculate the equivalent resistance of windings, it cannot be applied to components that do not fit with classical 1D assumption, which is the case of gapped magnetic components. These structures can be accurately analyzed using finite-element analysis (FEA) with the time cost that this represents. Modifying the Dowelĺs equation, and taking advantage of the orthogonality between skin and proximity effects, a simple solution that allows its application in gapped magnetic components is proposed in this work, which results shows a very good accuracy compared with experimental measurements

Power losses calculations in windings of gapped magnetic components: The i2D method applied to flyback transformers

The improved 2-D equivalent analytical calculation method to estimate conductive losses in gapped magnetic components in a wide range of frequencies is extended to the calculations of conduction losses in flyback transformers. The i2D method, that is applicable to power inductor, is extended is extended to the winding loss calculation in gapped transformers, such as flyback transformers, by means of harmonic decomposition of the current though the windings that allows the proximity field calculation and, afterward, the estimation of the losses in the windings

Optimizing three-phase planar transformer construction

A three-phase transformer with flat conductor layers is proposed in this article. This arrangement is used for high current density transformers. Cost effectiveness in planar magnetic are related with the optimization in the number of layers in each winding. This fact takes more relevance for the medium and high power three-phase transformers where the number of parallels to achieve the required DCR is increased. The proposed method allows the use of off-the-shell core shapes that are used for single phase transformers. Cost impact is significant and design implications become more flexible. The proposed solution has been validated and compared using the conventional and the proposed methodologies to design a high power (20 kW) transformer

An alternative for reducing the layers in the construction of three-phase planar transformers

A modified winding layout for three-phase transformers with PCB windings is proposed in this paper. This modified layout can be used in high current transformers with many PCB layers to simplify the fabrication process. One of the key factors that might increase the cost and complexity in the construction of planar transformers is the number of layers of each PCB winding. This issue becomes even more important in medium-high power three-phase transformers, where the number of PCB layers is higher. In addition to that, the proposed method allows the use of commercial core shapes that are commonly used to design single-phase transformers. This fact makes possible the reduction of cost and flexibility of the design solutions. The proposed solution has been validated and compared using the conventional and the proposed methodologies to design a high power (20 kW) transformer

Red adaptativa de conmutación suave para convertidor trifásico en puente activo completo para aplicaciones de vehículos eléctricos

En éste artículo se presenta el control adaptativo de un circuito auxiliar para conseguir conmutaciones suaves en todo el rango de carga en los semiconductores principales de un convertidor cargador de baterías trifásico basado en doble puente activo. Mediante este sistema se consigue tener ZVS en todo el margen de carga, sin ser necesaria la modificación de los parámetros del circuito ni de los semiconductores principales. Los principios de operación de este circuito y su control se comprobarán experimentalmente en un convertidor cargador de baterías de características similares al utilizado en el HYBRID TOYOTA PRIU

Fuente de Alimentación para los Imanes Superconductores del Acelerador de Partículas Europeo XFEL

En este artículo se presenta la fuente de alimentación que se está diseñando para alimentar los imanes superconductores del acelerador de partículas europeo XFEL que se está construyendo en Hamburgo, cuyas características le hacen el más avanzado del mundo. Un imán superconductor es una carga muy inductiva que debe ser controlada en corriente y que presenta una caída de tensión muy baja cuando está en modo superconductor. La fuente debe ser capaz de alimentar esta carga con una alta fiabilidad e incorporar varias protecciones que protejan esta carga tan especial