A new SOGI-PLL method based on fuzzy logic for grid connected PV inverter

Phase angle detection of the grid voltage is an imperative part of control in most applications, especially for the synchronization of the current injected by the grid-connected photovoltaic inverters. Consequently, fast and accurate detection of the phase angle, frequency and amplitude of the grid voltage are indispensable data to ensure a correct generation of reference signals and operation of the grid connected inverters. We present in this work a new phase-locked loop (PLL) method for single-phase systems. The novelty is to generate an orthogonal voltage system using a second-order generalized integrator (SOGI), followed by a Park transformation, whose quadrature component is forced to zero by the fuzzy logic, in order to obtain rapid detection and a more accurate picture of the phase angle. Furthermore, simulation results with PSIM software will be submitted to verify the performance and effectiveness of the proposed method strategy. Finally, the experimental test will be used to extract the result and discuss the validity of the proposed algorithm.

A fuzzy rule based approach for islanding detection in grid connected inverter systems

Islanding is when an area of the electrical distribution system is isolated from the electrical system while being powered by distributed generators. An important condition for the interconnection of power plants and distribution systems is the ability of the power plant to detect islands. The presented and proposed method is a combination of best active sandia frequency shift (SFS) method with the intelligent fuzzy logic controller, which has been tested in distributed production using the island detection function. And the choice to improve the method by fuzzy logic control (FLC) is retained, as this process is more effective in decreasing the non-detection zone (NDZ) and in further improving the efficiency of the islanding detection system. This paper proposes a new active islanding detection technique controlled by a fuzzy logic controller, for grid connected photovoltaic (PV) inverters. In addition, the efficiency and performance of the proposed method strategy for islanding detection has been analyzed and tested in the various situations of the network. In addition, the results of the simulations with the power simulation (PSIM) software will be provided to illustrate the main conclusions and the development of the control. Thus, will be used to show the feasibility and validity of the proposed new algorithm

Integral sliding-mode controller for maximum power point tracking in the grid-connected photovoltaic systems

The output power generated in the photovoltaic modules depends both on the solar radiation and the temperature of the solar cells. To maximize the efficiency of the system, it is required to monitor the maximum power point of the photovoltaic system. For this purpose, monitoring the maximum power point (MPPT) of photovoltaic systems should be as quick and accurately as possible for increasing energy production, which ultimately increases the cost-efficiency of the photovoltaic system. This paper proposes a new approach for MPPT) using the concept of the integral sliding mode controller (ISMC) to ensure fast and precise monitoring of the peak power. The performance of the ISMC is significantly influenced by the choice of the sliding surface. To assess the reliability ISMC control, the results have been compared with those of a PI controller. The results obtained are used to evaluate the performance of the ISMC strategy under different climatic conditions. Finally, the effectiveness of the proposed solution is confirmed using simulations in PSIM tools and experimental results were used to evaluate the effectiveness of the proposed approach

Extraction des paramètres des modèles du VDMOS à partir des caractéristiques en commutation - comparaison avec les approches classiques

Ce mémoire porte sur l\u27analyse et la caractérisation du comportement du transistor MOS de puissance. La première partie du mémoire rappelle la structure, le comportement et la modélisation du transistor MOS de puissance. Un modèle semi-empirique dit " à deux KP " a été choisi. La mise en uvre des caractéristiques expérimentales de type statique I(V), dynamique C(V) ou en commutation est présentée. En particulier le rôle de la durée des impulsions des caractérisations quasi-statiques est étudiée. La seconde partie traite la caractérisation expérimentale et l\u27extraction classique des paramètres des modèles de type VDMOS basée sur les mesures I(V) et C(V). La confrontation entre simulation et expérience en régime de commutation sur charge RL est faite. La troisième partie traite de l\u27extraction des paramètres en se basant sur la commutation sur charge R-L dans une cellule de commutation. Les signaux temporels mesurés pendant les commutations du composant fournissent des informations utiles à l\u27extraction des paramètres. La procédure d\u27identification automatique est basée sur des méthodes d\u27optimisation avec un critère de comparaison entre des mesures et les simulations correspondantes. Ainsi nous avons pu confronter les résultats expérimentaux avec ceux obtenus par simulation en utilisant le simulateur PACTE développé au CEGELY. Les configurations les mieux adaptées à l\u27extraction des paramètres du transistor MOS de puissance, ont été évaluées. Les résultats obtenus montrent une équivalence par rapport aux méthodes classiques. L\u27intérêt de la méthode d\u27extraction en commutation que nous avons présentée réside dans une bien moins grande sensibilité aux bruits de mesure