Rafael Diez

• Pontifical Xavierian University

The aim of this article is to improve the performance of DBD excimer lamps systems for UV production. Within this framework, our approach considers two distinct directions: the geometric dimensions of the double-barrier lamp bulb and the characteristics of the power supply. To explore these directions, a sampling of 19 bulbs of different geometries...

This work presents a simple power converter, without any high voltage transformer, able to supply and control a plasma jet based on dielectric barrier discharge. The converter, operating in pulsed current mode, requires a single power switch and is fed by a low voltage DC source. It can deliver very short duration pulses to the plasma jet with high...

This article presents a decentralized control technique applied to a Cascaded Full-Bridge Multilevel Converter (CFBMC) to balance the amount of power provided by its independent cells connected in series. It is based on the use of elementary modular controllers, associated with each converter cell, communicating with their close neighbors to obtain...

In modern inverter applications, multilevel converters are used thanks to their capability of reducing the passive fi lter volumes, improving the overall THD, sharing the power sources across the several converter cells, and providing a reconfi guration ability in case of failure. However, increasing the number of cells makes more complex the contr...

The framework of this paper is the study of gas treatments (NOx abatement) by dielectric barrier discharge (DBD) at atmospheric pressure. To investigate the impact of various solutions for electrical energy injection on the treatment process, two diagnostic methods are considered to evaluate the discharging ratio on the reactor surface: an image pr...

Global Horizontal Irradiance was measured using a thermopile-type pyranometer during more than three years using a sample time of two seconds, with the purpose of capturing fast transient events of irradiance which are notable in tropical regions as the one where these data were collected: Bogotá, Colombia. The date and time of each measurement wer...

Selective Harmonics Elimination is a high-efficiency modulation method for multilevel inverters that allows handling very high voltage applications. It eliminates the most significant harmonics and fixes the desired fundamental component. The main issue of these techniques is the complex process to obtain the appropriate switching-angles, being nec...

This article presents an experimental study of a DBD-driven plasma jet system. The aim of the study is to design a whole system (the jet reactor, its electrical power supply, and a gas-feeding apparatus) suitable for biomedical applications. The article describes the test bench developed for this purpose and discusses the parameters it controls. Th...

This work presents an analysis of the full-bridge voltage inverter widely used to supply dielectric barrier discharges. The main contribution of this work is the deduction of the analytical equations for the delivered power, peak voltage and duration of the discharge as a function of the DC input voltage and of the switching frequency, but also, as...

This paper presents a decentralised control strategy for the balancing of the cell-voltages of a Flying Capacitor Multilevel Converter implementing a large number of cells to address high conversion ratio. The originality of this work is that no reference is required for regulating the capacitor voltages leading to an auto-balance capability. It is...

Este trabajo presenta el análisis de una fuente de voltaje bipolar cuadrada compuesta por un puente completo y un transformador elevador, utilizada ampliamente como suministro para sistemas de descarga de barrera dieléctrica (DBD) en la generación de plasma no térmico. Primero se expone un esquema eléctrico de la fuente que incluye el comportamient...

In the present study, the decolorization efficiencies of LP-Hg lamp, XeCl and KrCl excilamps at the same power density were compared for the decolorization of dyes in water by UV and UV/H 2 O 2 processes in a batch reactor. Laboratory prototypes of XeCl and KrCl excilamps and a commercial LP-Hg lamp were studied as UV sources. Methylene Blue and El...

Excimer lamps take place among the numerous industrial applications which rely on cold plasmas generated by means of Dielectric Barrier Discharges. For the performance and reliability of these applications, the control of the electrical energy injected into the plasma is of prominent importance; it also contributes to the homogeneity of the electri...

This article deals with the modulation and control of a Trinary Hybrid Multilevel Inverter (THMI), which is a cascade multilevel converter that maximizes the number of levels per Full Bridge. The modulation presented defines the duty cycle of switches as piece-wise functions of the desired output voltage, minimizing the processing time. In order to...

Power estimation of a DBD device supplied by a current source converter is studied in this paper, pointing out the prominent contribution of the transformer parasitic elements. The impact of the stray capacitance and magnetizing inductance are stated and an iterative method that estimates the electrical power and DBD waveforms is presented. Results...

This paper presents the analysis of a Series Resonant Inverter for Dielectric Barrier Discharge (DBD) applications, operating in discontinuous current mode. The study of different factors that can improve the efficiency and behavior of the converter are presented. First, the implementation of the converter is studied with two possible locations of...

A Dielectric Barrier Discharge driven cold plasma jet is ignited using three different power supplies to experimentally study the impact of the electrical operating point over several jet characteristics. The characteristics under study are the homogeneity of the jet and the gas temperature. Additionally, the jet reactor is operated at different ga...

This paper presents the design of a system aimed at characterizing a diverse set of dielectric barrier discharge UV lamps. This experimental bench allows the study of the lamps performances regarding UV emission maximization and energy conversion optimization. It includes a current-mode pulsed power supply for the lamps, the design of which is deta...

This paper presents how the parasitic elements of the step-up transformer impact the DBD operation, while supplied with a current-mode converter. The initial analysis is performed with the state-plane technique and then the steady-state values are calculated with an iterative method. Results show that the increase of power in the DBD can be achieve...

When performing tests on a photovoltaic energy conversion system, it is useful to have a daily-term irradiance profile which, in some way, represents the typical behavior of this variable at a desired geographic location, including fast changes caused by weather. Therefore, the objective of this work is to propose a simple methodology, to choose a...

A parametric study of a system dedicated to non-coherent UV emission, by means of DBD excilamps, supplied by a controlled square shape current source is proposed. The presentation highlights on the one hand the performances experimentally obtained by combining together a set of 20 different bulbs with different diameters, gap and wall thicknesses (...

The Dielectric Barrier Discharge (DBD) Excimer Ultra-Violet (UV) lamps are a promising technology offering several advantages over other sources of UV light. In particular, the application of this type of lamps for drinking water treatment could benefit thousands of people in regions where public access to drinking water is not provided. To optimiz...

Three different electrical generators have been designed and used to supply an exciplex dielectric barrier discharge lamp in order to elucidate the influence of each one of these supplying strategies over the system performance; the first method consists on supplying the lamp with short bipolar voltage pulses; the second and third methods are based...

A parametric study of a system dedicated to non-coherent UV emission, by means of DBD excilamps, supplied by a controlled square shape current source is proposed. The presentation highlights on the one hand the performances experimentally obtained by combining together: • A set of 20 different bulbs with different diameters, gap and wall thicknesse...

This paper is focused on studying a resonant current converter for the electrical supply of dielectric barrier discharge devices. To understand the impact of parasitic capacitances and incorporate them into the design of an optimised power supply, this approach theoretically analyses a boost-based resonant converter, considering switch capacitance...

In this work the procedure to design a power supply capable of supplying nineteen different exciplex Dielectric Barrier Discharge (DBD) UV lamps, is shown. This power supply is studied with the aim to study the impact of the DBD lamp geometrical characteristics over system’s performances (UV emission, efficiency). The pulsed power supply can contro...

Excimer and exciplex lamps are gas discharge spontaneous UV or VUV sources [1]. The virtues of such lamps from the standpoint of their application are high photon energy (3.5 – 10 eV), a narrow emission band, and the possibility of scaling and selecting an arbitrary geometry of the emitting surface [2]. Three different electrical generators have b...

This article presents a study of a design of four controllers to a ladder converter modeled by the generalized equivalent continuous model. Two controllers are designed minimizing the energy of the input and minimizing the states; and the other two controllers are designed minimizing the changes in the input, and the states. Also, the article shows...

Dielectric barrier discharge (DBD) excimer lamps are efficient and environmentally friendly sources of ultraviolet (UV). One of the challenges for this technology to be massively adopted is the optimization and effective management of the overall lamp-supply system. Accordingly, a methodology to study the impact of the operating point over the perfo...

In this paper various schemes for solar photovoltaic water pumping are analyzed. Different aspects influence the performance of those systems; hydraulic load, battery efficiency, and variable speed operation are taken into account in order to suggest strategies for energy management and hardware implementation alternatives, under the restriction of...

This work presents the use of a current-mode static converter to study the possible operating points of a Dielectric Barrier Discharge (DBD) excimer lamp and to select the optimal operating conditions. This converter is capable to inject a pulsed current within the bulb, controlling three independent parameters of these pulses: amplitude I, duratio...

This work presents the design, implementation and tests of an energy conversion system, formed by a Buck converter and a bidirectional DC-DC converter. The system is able to obtain the maximum power from a photovoltaic solar module, using an MPPT algorithm. Besides, the system is capable of, obtaining, storing and delivering energy in an isolated w...

With the aim of providing a power supply for the study of dielectric barrier discharge (DBD) excimer lamps (excilamps), a current-mode converter that allows for an accurate adjustment of the electrical power injected into one of those lamps is designed and implemented. Starting from the electrical model of the DBD lamps, the convenience of using a...

This document reviews the current-mode supply approach for dielectric barrier discharge (DBD) excilamps. It briefly demonstrates why this mode assures the control of the power injected into the DBD. Considerations with the step-up transformer required for the correct operation of the current-mode are developed. This document shows and compares four...

This study analyzes a ladder multilevel converter (double ladder topology) with the use of a new averaging modeling technique. This technique introduces an analytical method to compute for the switching losses and is used to conduct an in-depth analysis of the influence of the switching frequency and parasitic resistance of components on converter...

This paper presents the study of a series-resonant inverter for the supply of a dielectric barrier discharge excimer lamp. Causal analysis, based on the fundamental properties of the load, is used to detail the reasoning which has led to this topology. In order to effectively control the lamp power, the operating mode of this converter combines dis...

This paper presents a study of couplings which take place in systems where dielectric barrier discharge (DBD) excimer lamps are supplied with current source electrical power generators. Causal analysis, using the fundamental properties of the DBD, is used for the design of such current sources. A two steps approach is developed here: in order to co...

This paper presents an analysis of the consequences of using a step-up transformer in the supply of a dielectric barrier discharge (DBD) excimer lamp. A simplified transformer model is used to analyze the effects of the different parasitic elements in the operation of a current mode power supply. Mathematical expressions are found for each element...

This work presents the development of an electronic ballast based on the Class E resonant inverter, which controls directly the radiated light intensity, instead of the lamp current. The control proposed in this paper improves the settling time of the output light and compensates the wearing out of the electrodes of fluorescent lamps, since, even i...

In Dielectric Barrier Discharges (DBDs), the control of the power transfer, from the low-voltage static converter to the high voltage DBD, is strongly affected by the parasitic capacitive effects of the step-up transformer. Minimizing these capacitances is of major importance and this paper aims to establish and validate analytical expressions in o...

This paper proposes an efficient modeling and an identification method for dielectric barrier discharge (DBD) systems, based on input–output (current–voltage) experimental measurements. The DBD is modeled using an equivalent electric circuit associated with a differential equation that describes the dynamics of its conductance. This equation assume...

In this paper the design, implementation and tests of a DC-DC Buck converter is detailed. This converter operates in the maximum power point thanks to an MPPT algorithm implemented in a DSP. The simulation of the converter is done in PSIM. Implementation and experimental results, validating the design, are shown.

In this paper the design and implementation of an electronic ballast based on a Class E resonant inverter with frequency control, powered by a 12 V battery, is presented. This ballast pretends to be used where a connection to an electric grid is not available. In order to control the output power and compensate the battery voltage variations, the f...

This article proposes a new technique of continuous modeling for switched systems represented as piecewise linear time invariant (LTI) systems over the state space variable. A procedure to calculate the Root Mean Square (RMS) value in one switching period of selected outputs based on this technique is also shown. The proposed model searches to comp...

This paper presents the study of a series-resonant inverter for the supply of a dielectric barrier discharge (DBD) excimer lamp. Causal analysis, based on the fundamental properties of the load, is used to justify the choice of this topology. In order to correctly control the lamp power, the operating mode selected for this converter combines disco...

An accurate average modeling technique for power converters is important in order to be able to analyze the converters and design proper control laws. The classical technique works well under the slow dynamics assumption in the state space variables. For certain power converters, such as switched capacitor converters, this assumption is not satisfi...

In this paper, three dc/dc ladder multilevel converters are compared. The first one is the classical ladder topology and the two other topologies presented are based on the classical one. A mathematical calculation of the output resistance and the gain of the converter as a function of the number of levels is carried out for the three topologies in...

Dielectric barrier discharge (DBD) lamps, being capacitive loads, must be associated with bidirectional current sources for an appropriate control of the transferred power. Pulsed current source supplies, which are known to offer very interesting performances, require specific power switches that are able to manage bidirectional voltage and unidire...

Based on causality analysis relying on the capacitive nature of the Dielectric Barrier Discharge (DBD) excimer lamps, a converter that allows the variation of the electrical power injected to a KrCl excimer lamp is designed and implemented. This converter is capable of controlling the lamp current by means of the three degrees of freedom (D.O.F.) o...

A pulsed current-mode converter specifically de- signed for the supply of dielectric barrier discharge excimer lamps is proposed in this paper. The power supply structure is defined on the basis of causality criteria that are justified by the structure of the lamp model. The converter operation is studied, and its design criteria are established us...

In this article different control methods for a ladder multilevel converter (two cells) are evaluated. An analysis of the classical average model allows to chose a set of operation points and construct an uncertain model. Moreover, the necessary disturbance variables and performance masks are defined. All this information is used to design an H∞ “m...

The efficiency of the electrical power transfer to the gas mixture of a XeCl dielectric barrier discharge (DBD) exciplex lamp is analysed. An equivalent circuit model of the DBD is considered. It is shown that the excilamp power can be controlled by applying current to the lamp. This highly desired property is ensured by means of a specific power s...

Neste artigo analisa-se e desenha-se um conversor multinível em topologia tipo escada para una aplicação de alta voltagem (3000 V). Este conversor é comparado com outra estrutura conhecida chamada flying capacitors e mostra sua simplicidade na implementação e no controle. Adicionalmente, analisam as quedas de voltagem a topologia tipo escada em fun...

In this paper a ladder multilevel converter topology for an application of high voltage is analyzed. This converter is compared with other well-known structure called "Flying Capacitors" showing its simplicity on the implementation and control. Furthermore, the converter is implemented and its voltage drop is tested experimentally varying the numbe...

UV excimer lamps are efficient narrowband sources of UV radiation with applications in various domains. The issue of controlling the UV emission by means of the power supply associated with such lamps favors pulsed current-controlled generators. After having established the previous statements, we propose a dedicated power converter topology which...

This work proposes the development of a power supply for Dielectric Barrier Discharge (DBD) lamps, intended for the evaluation of a water treatment system based on UV radiation. The DBD excimer lamp is an attractive source of UV because of its cost and radiation power. The proposed converter is conceived to control the UV radiation by programming d...

This paper presents a design process of the power supply for a dielectric barrier discharge (DBD) lamp; this design is based on an electrical model of DBD lamps. An identification algorithm is used to find the values of the parameters of the model, on the basis of several experimental waveforms. With the identified model, the design phase of the po...

This paper proposes a particular DC/DC multilevel converter topology called ladder topology for high voltage applications. This topology elevates the input supply voltage using few control signals. Some simple comparisons with the classical flying capacitor converter are carried out. Moreover, power losses are also analyzed. The good performance of...

The UV power, emitted by a XeCl Dielectric Barrier Discharge exciplex lamp, is shown, on the basis of causality analysis, to be controllable by the current supplied to the lamp. Experimentally, the UV radiation is demonstrated to be proportional to the current injected into the gas. A current-mode converter operating in discontinuous current mode c...

This work presents a reasoned approach to deliver electric energy into a dielectric barrier discharge exciplex lamp, with the aim of controlling its UV emission. An electrical model of the lamp has been developed and identified, in order to study the interactions between the power supply and the lamp. This model is also employed to perform the synt...

Ce travail présente une approche raisonnée pour alimenter en énergie électrique une lampe exciplexe à décharge à barrière diélectrique, en vue du contrôle du rayonnement UV produit. Un modèle électrique de la lampe a été développé et identifié, permettant d'étudier les interactions alimentation-lampe. Ce modèle est également utilisé pour effectuer...

The coupling between the power supply and a Dielectric Barrier Discharge (DBD) for UV production purposes (excilamp) is a major issue for the design of powerful and efficient UV sources. In order to improve this coupling, new power supply topologies have been developed, based on the current control of the DBD. The aim of this paper is to present th...

This paper presents the design of a current converter to supply a DBD exciplex lamp. The structure is implemented, based on a Boost converter. An analysis in the state plane is used, to determine the stability of the converter and the values of current and voltage during the discharge phase. An electrical model of the lamp is used to simulate the n...

This paper presents a novel concept of supplying a dielectric barrier discharge (DBD) lamp. An electrical model of the lamp is used in a circuit simulator to study the interactions between the converter and the load, which presents a capacitive nature. The current mode supply is chosen instead of the classical voltage mode, in order to respect the...

Excimer and exciplex UV/VUV sources excited by Dielectric Barrier Discharges represent a promising technology for industrial applications where powerful and efficient UV sources are needed. According to previous work, the most suited power supply waveform for coaxial DBD Excilamps is a unipolar pulsed voltage excitation of some kilovolts at some hu...

Excilamps are artificial Ultraviolet sources based on the emission of excimers or exciplexes. These latter are excited states of weakly bound rare gas or halide/rare gas atoms which emit a photon in the UV region when they dissociate. Dielectric Barrier Discharge (DBD) excilamps are promizing UV sources for the future, provided the coupling between...

An electrical model for a dielectric barrier discharge (DBD) is proposed, with the aim of its application in power supply design process. An identification method, which finds the actual value of the parameters in a model, is presented. The specific modelling of a XeCl exciplex lamp is developed, along with the identification procedure of the p...