Fuzzy controller tuning of a boost rectifier unity power factor correction by experimental designs

This paper shows the validity of experimental designs as an efficient on-site tuning tool for fuzzy controllers, dedicated to electrical engineering applications with multi-objective criteria. Our purpose is to improve the input and output system characteristics that is to say the global quality of the electrical power in a boost rectifier with unity power factor correction. The desirability notion combines here time dynamic and harmonic criteria, it illustrates the trade-off that has to be satisfied between the different properties

Les plans d'expériences pour le réglage de commandes à base de logique floue

Les commandes à base de logique floue ont connu un succès croissant depuis la fin du siècle dernier, notamment dans le domaine du génie électrique. Celles-ci apportent en effet une amélioration significative des performances par rapport à des commandes linéaires plus classiques. Cependant, les paramètres de ce type de commande sont nombreux et délicats à régler. Le fil conducteur de ces travaux consiste alors à proposer des méthodologies de réglage simples pour des commandes à base de logique floue dédiées à des systèmes électrotechniques. La procédure de réglage proposée repose sur l'utilisation de la méthodologie des plans d'expériences. Celle-ci permet d'étudier un ou plusieurs critères en organisant un minimum d'essais. De ce fait, en réalisant une étude sur le système expérimental ou en simulation, il est possible d'obtenir des informations conduisant à la définition d'un réglage simple du correcteur étudié. De plus, l'existence de logiciels dédiés permet de mettre en oeuvre rapidement et simplement cet outil sans passer par une phase de formation importante. A fin de validation expérimentale, cette méthodologie a été utilisée pour régler différentes structures reposant sur la logique floue et commandant des convertisseurs statiques de natures distinctes répondant à des cahiers des charges spécifiques pour des objectifs multiples ou non et prenant en compte la notion de robustesse : – hacheur buck de type DC/DC ayant une réponse indicielle de type sousamortie pour un objectif temporel mono-critère, – redresseur boost à absorption sinus de type AC/DC pour un objectif temporel multi-critère, – hacheur mode courant de type DC/DC ayant une réponse indicielle de type sur-amortie pour un objectif fréquentiel multi-critère. L'application de la procédure de réglage proposée à ces trois systèmes a donné des résultats remarquables montrant ainsi l'intérˆet de cette approche méthodologique. ABSTRACT : Fuzzy-logic-based controllers are widely used in various applications, mainly because of advantages such as the dynamic performances or the robustness. Nevertheless, the control parameters are numerous and rather delicate to tune. The objective of this study is then to propose a simple methodology to tune fuzzy controllers dedicated to electromechanical systems. This methodology relies on experimental designs. The principle consists in scheduling experiments so as to obtain for a specific issue the most accurate information with a minimum number of experiments, leading to the tuning of the controller. This methodological tool is easy to use through specific software. The experimental validation of the methodology is realised on three different systems (DC/DC or AC/DC converters with under or over damped behaviour) with the following specifications : mono or multi objective criteria, temporal or frequential properties, taking into account robustness

Transition from plasma- to Kerr-driven laser filamentation

While filaments are generally interpreted as a dynamic balance between Kerr focusing and plasma defocusing, the role of the higher-order Kerr effect (HOKE) is actively debated as a potentially dominant defocusing contribution to filament stabilization. In a pump-probe experiment supported by numerical simulations, we demonstrate the transition between two distinct filamentation regimes at 800\,nm. For long pulses (1.2 ps), the plasma substantially contributes to filamentation, while this contribution vanishes for short pulses (70 fs). These results confirm the occurrence, in adequate conditions, of filamentation driven by the HOKE rather than by plasma.Comment: 6 pages, 4 figures. Accepted for publication in Physical Review Letter

On-line electrical quality improvement of a single phase boost rectifier with fuzzy controller and experimental designs

This paper shows the validity of experimental design methodology as an efficient on-line tuning tool for a fuzzy logic controller (FLC) dedicated to electrical engineering applications with multi-objective criteria. Our purpose is to improve the input and output system characteristics as well as the global quality of electrical power. Experimental designs give FLC parameters effects with a reduced number of experiments and allow to estimate the response surface for the selected criteria. Factor effects are dependant on the chosen levels of the experimental parameters but the estimated response surface analytical optimum can be found between those levels. The desirability notion combines here time dynamic and harmonic criteria for a boost rectifier with unity power factor correction and illustrates the trade-off that has to be made between the different properties. Criteria improvements with the tuned FLC are sizeable in comparison with a PI linear controller

Les plans d'expériences pour le réglage de commandes à base de logique floue

Les commandes à base de logique floue ont connu un succès croissant depuis la fin du siècle dernier, apportant une amélioration significative des performances par rapport à des commandes linéaires plus classiques. Cependant, les paramètres de ce type de commande sont nombreux et délicats à régler. Le fil conducteur de ces travaux consiste à proposer des méthodologies de réglage simples pour des commandes floues dédiées à des systèmes électrotechniques. La procédure proposée, les plans d expériences, permet d étudier expérimentalement ou en simulation un ou plusieurs critères en organisant un minimum d essais conduisant à la définition d un réglage simple du correcteur étudié. A fin de validation expérimentale, cette méthodologie a été utilisée pour régler différentes structures reposant sur la logique floue et commandant des convertisseurs statiques de natures distinctes pour des objectifs temporels ou fréquentiels, multiples ou non et prenant en compte la notion de robustesse.Fuzzy-logic-based controllers are widely used in various applications, mainly because of advantages such as the dynamic performances or the robustness. Nevertheless, the control parameters are numerous and rather delicate to tune. The objective of this study is then to propose a simple methodology to tune fuzzy controllers dedicated to electromechanical systems. This methodology relies on experimental designs. The principle consists in scheduling experiments so as to obtain for a specific issue the most accurate information with a minimum number of experiments, leading to the tuning of the controller. This methodological tool is easy to use through specific software. The experimental validation of the methodology is realised on three different systems (DC/DC or AC/DC converters with under or over damped behaviour) with the following specifications: mono or multi objective criteria, temporal or frequential properties, taking into account robustness.TOULOUSE-ENSEEIHT (315552331) / SudocSudocFranceF

Associative methods for dc/dc power electronics control

This paper describes two different control principles using simple combinations between basic control laws. The objective is to improve the performance (time response, overshoot, robustness…), without strongly increasing the complexity. These principles are tested on a dc-dc power converter. Linear and/or non linear controllers are mixed depending on the optimisation objective and on the decision data. The basic idea is that in the world of control, as elsewhere, “unity is strength”, i.e. complex functions could be carried out through basic object combinations

Electrical Ageing Modeling of the Insulation of Low Voltage Rotating Machines Fed by Inverters with the Design of Experiments (DoE) Method

International audienceIn the context of more electric aircrafts, the reliability of the low voltage insulation systems in rotating machines is an important issue. But, modeling and understanding their electrical ageing is a complex phenomenon especially when they are fed by PWM inverter. They involve a large amount of parameters related to both operating conditions and material design, which act together. Accelerated ageing tests are usually run in order to describe the electrical ageing process and to determine the lifetime of these materials. Nevertheless, full ageing tests with all the various parameters for different samples become rapidly time consuming. Moreover, there is not any complete model for insulation lifetime prediction under accelerated ageing tests. In this paper work, we propose a method based on the design of experiments (DoE) method, which is a useful statistical approach that would lead to a reliable and significant interpretation of the different ordering parameters of the insulation ageing process. Moreover, this method will help to reduce the number of required experimental or numerical trials and will, take into account the possible failure mechanisms and the various synergetic effects between them. Using the (DoE) method, a preliminary model of the insulation “lifetime” is presented with respect to the most important parameters at play and interactions between them

Electrical Aging of the Insulation of Low Voltage Machines: Model definition and test with the Design of Experiments

International audienceThe aim of this paper is to present a method for modeling the lifespan of insulation materials in a partial discharge regime. Based on the design of experiments, it has many advantages: it reduces the number of time-consuming experiments, increases the accuracy of the results and allows lifespan modeling under various stress conditions including coupling effects between the factors. Accelerated aging tests are carried out to determine the lifespan of these materials. The resulting model presents an original relationship between the logarithm of the insulation lifespan and that of electrically applied stress and an exponential form of the temperature. Results show that the most influential factors can be identified according to their effects on the insulation lifespan. Moreover, the lifespan model validity is tested either with additional points which have not been used for modeling or through statistical tests. Finally, it is shown that fractional plans are not suitable to reduce the number of experiments. This application of the experimental design is best used during the initial phase, before the final drive has been built and any on-line diagnostic

Optimal design of the Integrated Modular Power Electronics Cabinet

International audienceThis paper deals with a new concept of electrical power distribution system called IMPEC for Integrated Modular Power Electronics Cabinet. The paper defines methods aiming at carrying out an optimal design of IMPEC, the main variables being on one hand the number and size of power electronics module. On the other hand, reconfigurations between these modules and electrical loads are also optimized.The formalization of the problem highlights that designers must deal simultaneously with a combinatorial explosion and a multi-physical system sizing. The main objective of the study is to propose a methodological framework for solving this original optimal design problem. A heuristic-based algorithm is developed to solve this combinatorial optimization problem. A particular attention is paid to develop a weight estimation procedure using generic sizing models. Finally a mapping is performed to identify the best solutions and to highlight the technological components having the most significant sensitivity on the complete system weight