Simulateur de Production Solaire : un outil pédagogique innovant dédié à l’enseignement des principes fondamentaux de l’énergie photovoltaïque

Cet article décrit une nouvelle approche pédagogique pour l’enseignement des connaissances de base de l'énergie solaire et des applications photovoltaïques. Cette méthode d'enseignement expérimentale et interactive permet aux étudiants et aux concepteurs de systèmes photovoltaïques de manipuler un simulateur de production solaire. Cet outil de simulation reproduit à échelle réduite la trajectoire du soleil quelle que soit la période de l’année. La production d'énergie est ensuite calculée pour différentes inclinaisons et orientations d'un capteur solaire. Le simulateur offre aux étudiants l'occasion d'acquérir d’une façon ludique les fondamentaux de l’énergie photovoltaïque. Plusieurs exemples de travaux pratiques sont détaillés afin de donner une vue d'ensemble des exercices d'apprentissage qui pourraient être faits par les étudiants pour découvrir les multiples applications du photovoltaïque. À titre d’exemple, de nombreux cas d’études peuvent être traités tels que la mise en oeuvre des calculs de position du soleil, la caractérisation électrique des cellules solaires avec différentes technologies ou encore la programmation de suiveurs du point de puissance maximale

Contribution to the estimation and to the improvement of the photovoltaic energy production

Ces travaux de thèse consistent à proposer des outils matériels et logiciels pour estimer et améliorer le rendement énergétique de la chaine de conversion d’énergie photovoltaïque pour les applications de l’habitat. Nous avons dans un premier temps proposé une nouvelle architecture mixte d’onduleur à 5 niveaux. Ce type de structure, fondé sur un couplage d’un onduleur en pont complet et d’une architecture NPC, permet de diminuer le THD de la tension de sortie du convertisseur tout en limitant les niveaux de courant de fuite induits par les modules photovoltaïques. Ce type d’architecture est constitué d’un nombre limité de dispositifs à semi-conducteurs par rapport à une structure NPC et permet d’améliorer la robustesse de l’onduleur. Ces premiers résultats de test à puissances réduite permettent de valider le concept proposé. On s’intéresse ensuite à l’étude des paramètres environnant du système pouvant impacter la production d’énergie. Il est mis en évidence l’influence de la variation du coefficient d’échange convectif avec la vitesse du vent. Pour cela, un outil flexible d’estimation de production a été développé. Il est alors possible de quantifier et de qualifier l’impact des conditions météorologiques sur la production d’énergie photovoltaïque.This study deals with the development of hardware and software tools to estimate and improve the efficiency of the PV energy conversion chain for household photovoltaic applications. We firstly proposed a new mixed 5-level inverter. This type of structure, based on the mixture of a full bridge inverter and NPC architecture, reduces the converter output voltage THD while reducing levels of leakage current induced by the PV modules. This architecture consists of a limited number of semiconductor devices with respect to a NPC structure and improves the robustness of the inverter. Several test results in reduced power validate the concept proposed. Finally, we focus on some parameters that could perturb the system and impact the energy production. It is highlighted that the impact of the convective heat transfer coefficient variation with wind speed is important. For this purpose, a flexible tool was developed to estimate the PV production. It is then possible to quantify and qualify the impact of wind speed on the photovoltaic energy production

PVLab, a Powerful, Innovative Software Package for the Simulation of Photovoltaic Systems

International audienceThis paper describes a new, highly modular, simulation tool named “PVLab” and developed by the GREMAN laboratory. It is designed to assist the designer in the sizing of PV (photovoltaic) installations. The programming structure and physical models implemented within this tool are described, and several case studies are proposed to highlight its relevance. The predicted yearly electrical energy production of grid-connected PV plants is discussed. In particular, the predicted performance of such plants is compared with that given by the PVsyst software. PVLab has a high level of flexibility, allowing its physical models and databases (e.g., meteorological data) to be modified according to the user’s needs. This is made possible through the use of expertise applied to all of the computing steps, and to the MATLAB development environment. The user’s ability to control the source code itself will allow much greater progress to be made in the field of renewable energy applications than with PVsyst, which is currently the commercial reference

New Multilevel Mixed Topology Development to Improve Inverter Robustness for Domestic Photovoltaic Installations

International audienceMultilevel inverters are well used in grid connected domestic photovoltaic applications because of their ability to generate a very good quality of waveforms, reducing switching frequency, and their low voltage stress across the power devices. However, this kind of inverter has to be modified to both limit common-mode currents and improve the robustness of the system. This paper presents a new mixed 5-level inverter that meets these challenges. The operating principle of the converter is proposed. Several experimental measurements are described to validate this new concept. The output voltage and current and the THD of the output voltage are particularly discussed

Lifetime Prediction Modeling of Non-Insulated TO-220AB Packages with Lead-Based Solder Joints during Power Cycling

International audienc

Development and Static Mode Characterization of a New Low-Loss AC Switch Based on Super-Gain BJT

International audienceThis paper deals with an innovative low-loss AC switch, named as TBBS (transistor based bidirectional switch), based on the association of super-gain BJTs developed by the GREMAN laboratory. The main characterization results of the super-gain BJT are reminded to identify the key parameters that are essential to build the TBBS. A complete characterization database in static mode of this new AC switch is discussed. In particular, its forward and reverse-biased features have been measured to see the evolution of the DC current gain as a function of the current density. The TBBS makes sense when using the super-gain BJT (bipolar junction transistor) in reverse mode. It means that the reverse DC current gain has to be sufficient (at least higher than 1 compared with the conventional BJT one). This new AC switch is bidirectional in current and voltage, totally controllable (turn-on and turn-off) and the most attractive solution in terms of on-state power losses. Further, its manufacturing process is as easier as existing device such as triac