Hubert Piquet

Current mode converter for dielectric barrier discharge lamp

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 causality considerations concerning these interactions. The converter is designed as a unidirectional current source in series with an H-bridge that inverts the current direction in the lamp each half cycle. Two different structures are presented to compose the unidirectional current source: a Boost based converter and a Buck-Boost based converter. Both converters are analyzed using the state plane and implemented, obtaining measurements that comply with the current mode concept. The presented structures allow the control of the current duration and amplitude, thus, the operating point in the discharge. This concept is the basis for the studies of correlation between the gas current and the UV emission.

Expert system for the CAD in power electronics-application to UPS

In this paper, an application using an expert system approach to power electronics design is presented. The authors goal is the development of a software tool for the computer-aided design of static power converters; they present here an initial approach, dedicated to uninterruptible power supplies (UPS). The specifications are described by the performances to be reached at the input and output of the power converter. These data are analyzed by use of rules and methods that allow achieving the design of the different parts of the system: the input filter; output filter; inverter; rectifier, etc. The characterization of these subparts, according to different criteria and specifications, has been made by the implementation of autonomous expert modules. Each of these modules has been designed and implemented independently from the others by use of the SMECI expert system shell; the design of the whole UPS is realized under the control of a special module that rules the cooperation between the specialized experts. The results of this approach are presented, and the benefits of its application are pointed out.

Current-Mode Approach in Power Supplies for DBD Excilamps: Review of 4 Topologies

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 different converter topologies that comply with this principle. This comparison is made in terms of electric efficiency and luminous efficacy using experimental measurements.

Optimizing the Operation of DBD Excilamps

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 performance and operation of a DBD UV excilamp is developed and experimentally validated. The DBD operating point is parametrically adjusted by means of the power supply current with three independent variables: intensity, frequency, and duty cycle. This methodology allows the determination of the optimal operating point for the particular excilamp under study. These supplying conditions will be later achieved by means of a dedicated electrical generator, which has to be especially designed according to these specifications. It is found that an increment in the current intensity has a positive impact on the lamp efficiency and also leads to the existence of more filamentary discharges. Also, a relation between the energy of the pulse supplied to the DBD and the reactor efficiency can be established. For certain levels of UV power, energy savings on the reactor higher than 50% are attained by proper selection of the operating point.

MPAB, Un outil pour l'étude et le développement de l'enseignement du contrôle numérique des convertisseurs

Cet article presente un systeme de controle numerique (MPAB) dedie a lenseignement de la commande numerique des convertisseurs statiques. Toujours en forte croissance, lutilisation de techniques numeriques recentes (utilisation de DSP et de FPGA) pour le pilotage des convertisseurs statiques permet un grand nombre de possibilites associe a une grande souplesse dutilisation. Ces nouvelles solutions numeriques apparaissent petit a petit chez les industriels et il est maintenant necessaire, dans le cycle de formation dun ingenieur, de connaitre et de maitriser ces techniques et technologies. Cet enseignement a donc pour objectif de familiariser les etudiants de deuxieme et troisieme annee dEcole dingenieur (Departement Genie Electrique / Automatique a lENSEEIHT) avec cette approche par le biais de cas detudes simples, comme la realisation dune source de courant controlee a laide dune cellule de commutation.