Modeling of Linear-Assisted DC-DC Converters

This paper shows the modeling of a linear–assisted or hybrid (linear & switching) DC–DC converters. In this kind of converters, an auxiliary linear regulator is used, which objective is to cancel the ripple at the output voltage and provide fast responses for load variations. On the other hand, a switching converter, connected in parallel with the linear regulator, allows to supply almost the whole output current demanded by the load. The objective of this topology is to take advantage of the suitable regulation characteristics that series linear voltage regulators have, but almost achieving the high efficiency that switching DC–DC converters provide. Linear–assisted DC–DC converters are feedback systems with potential instability. Therefore, their modeling is mandatory in order to obtain design guidelines and assure stability of the implemented power supply system.Postprint (published version

Burden resistor selection in current transformers for low power applications

In order to sense AC current with electric isolation in high frequency switching power converters the most simple and low cost solution is to consider a current transformer with a burden resistor. But burden resistor selection is not a simple task because involves a lot of considerations that affect the output voltage and its signal-to-noise ratio and the bandwidth of the measure. In this paper, considering the basic equations of the transformer and applying the Laplace Transformation is obtained a simple model of the current transformer interesting to select burden resistor and even to design the current transformer in case of high frequency applicationsPostprint (published version

High efficiency power amplifiers

Postprint (published version

Low Consumption Flux-Gate Transducer

Postprint (published version

LCLC resonant converter as maximum power point tracker in PV systems

This paper presents the analysis and implementation of an LCLC resonant converter working as maximum power point tracker (MPPT) in a PV system. This converter must guarantee a constant DC output voltage and must vary its effective input resistance in order to extract the maximum power of the PV generator. Preliminary analysis concludes that not all resonant load topologies can achieve the design conditions for a MPPT. Only the LCLC and LLC converter are suitable for this purpose.Peer ReviewedPostprint (published version

Single-Input Dual-Output (SIDO) Linear-Assisted DC/DC Converter

This article describes a single-input dual output (SIDO) linear-assisted DC/DC converter. Linear-assisted DC/DC converters are structures that allow to take advantages of the two classic alternatives in the design of power supply systems: voltage linear regulators and switching DC/DC converters. Thanks to the combination of a switching converter and two voltage linear regulators, the proposed SIDO converter provides two independent outputs with suitable load and line regulations. In the presented topology the SIDO linear-assisted DC/DC converter operates at the boundary of continuous conduction mode(CCM) and discontinuous conduction mode (DCM) with variable switching frequency.Postprint (published version

Mejoras en el consumo de energía de los transductores de corriente basados en el efecto flux-gate

En este trabajo se presenta una mejora en el diseño de los transductores de corriente flux-gate, con vistas a la reducción del consumo eléctrico de la electrónica de control. Esta mejora consiste en la substitución del amplificador lineal de compensación de flujo, que proporciona la salida de corriente de medida proporcional a la corriente principal, por un amplificador clase H, con lo cual se consigue reducir apreciablemente el consumo de energía de la electrónica sin afectar a las prestaciones del transducto r en cuanto a precisión, linealidad, etc.Postprint (published version

Aspectos comparativos en las estrategias de control de convertidores DC/DC híbridos

Dentro de los convertidores DC/DC híbridos, formados por un regulador lineal en paralelo con un convertidor conmutado, existen diferentes estrategias de control que permiten fijar la frecuencia de conmutación en función de alguna característica del regulador lineal. El presente artículo compara dos estrategias de control que, aunque pueden aplicarse a la misma estructura circuital de convertidor híbrido, son sensiblemente diferentes. La primera de ella, presentada en [1], considera como bloque principal al convertidor conmutado y, al regulador lineal, como módulo auxiliar. Por su parte, la propuesta realizada por los autores del presente artículo considera como conjunto principal al lineal y al conmutado como módulo auxiliar.Postprint (published version

Diseño e implementación de un convertidor DC/DC híbrido

El presente artículo muestra el diseño y realización práctica de una topología mixta o híbrida lineal–conmutada para convertidores de potencia DC/DC, formada por un regulador lineal de tensión y un convertidor conmutado DC/DC. El regulador lineal serie tiene como objetivo el cancelar los rizados de salida y proporcionar respuestas rápidas frente a variaciones de carga, mientras que el regulador conmutado, en paralelo con el lineal, permite proporcionar a la carga prácticamente la totalidad de la corriente demandada por la misma. La finalidad de la topología es la de obtener altos rendimientos, propios de los convertidores conmutados DC/DC, pero aprovechando las convenientes características de regulación que poseen los reguladores lineales serie de tensión. En el presente artículo se detalla el proceso de diseño e implementación de un convertidor híbrido de 80 W que permite alimentar cargas con tensiones de salida fácilmente ajustables. El diseño implementado ha permitido obtener corrientes de salida de hasta 8 A para tensiones de salida de hasta 10 V, con excelentes regulaciones tanto de línea como de cargas.Postprint (published version

Modeling of Linear-Assisted DC-DC Converters

This paper shows the modeling of a linear–assisted or hybrid (linear & switching) DC–DC converters. In this kind of converters, an auxiliary linear regulator is used, which objective is to cancel the ripple at the output voltage and provide fast responses for load variations. On the other hand, a switching converter, connected in parallel with the linear regulator, allows to supply almost the whole output current demanded by the load. The objective of this topology is to take advantage of the suitable regulation characteristics that series linear voltage regulators have, but almost achieving the high efficiency that switching DC–DC converters provide. Linear–assisted DC–DC converters are feedback systems with potential instability. Therefore, their modeling is mandatory in order to obtain design guidelines and assure stability of the implemented power supply system