Papers by Jean RAZAFINJAKA
The development and the exploitation of renewable energies met a great growth these last years. A... more The development and the exploitation of renewable energies met a great growth these last years. Among these sources of energies, the windmill represents a significant potential not to replace existing energies, but to give solutions for the request, which always increases. The wind power can contribute with a significant part for the new sources of energy not emitting a gas for purpose of greenhouse (Andrianantenaina and al 2015). Currently, windmill system with variable speed based on the DFIG is widely used. Indeed, the DFIG presents more advantages. Several controls applied on the DFIG have been already proposed as (Andrianantenaina and al 2015; Razafinjaka and Andrianantenaina 2015,2016; Boualouch 2015) which give good performances. These last years, several researches are about the intelligent controllers such us fuzzy logic and neural network which have enjoyed great success in recent years for their robustness against disturbances which may affect process. Here, a hybridization of fuzzy logic with variable gain PI is proposed. After modeling the wind turbine and DFIG, we have established a vector control to control the active and reactive power control. The aim of this work is to present the performance and robustness of these controllers.
International Journal of Engineering Research and, 2018
This paper deals with fuzzy-sliding mode control strategies of a Brushless AC Motor. The system c... more This paper deals with fuzzy-sliding mode control strategies of a Brushless AC Motor. The system combines the performance of fuzzy logic control and sliding mode control. Sliding mode control scheme, fuzzy logic controller strategies and the hybrid fuzzy-sliding mode controller were simulated with Matlab/ Simulink for comparison. Behind this strategy, the main objective is to improve the performance of the fuzzysliding mode control scheme. An experimentation, where all the command were implemented to an MSK23335 Board with a PM50 module and a 90W BLAC Motor is used to validate all the result.
Regular, 2020
In this context, we are taking a close interest in the optimization of wind energy production. It... more In this context, we are taking a close interest in the optimization of wind energy production. It consists in designing simple to implement control strategies of a wind energy conversion system, connected to the network based on the Double Fed Induction Generator (DFIG) driven by the Converter Machine Side (CSM) in order to improve the performance of Direct Torque Control (DTC) and Direct Power Control (DPC). For this purpose, the artificial neural networks (ANNs) is used. Hysteresis comparators and voltage vector switching tables have been replaced by a comparator based on artificial neural networks. The same structure is adopted to build the two neural controllers, for the DTC - ANN and for the DPC - ANN. The simulation results show that the combination of classical and artificial neural network methods permit a double advantage: remarkable performances compared to the DTC-C and DPC-C and a significant reduction of the fluctuations of the output quantities of the DFIG and especial...
International Journal of Engineering and Management Research
In this work, a neuro-fuzzy regulator based on ANFIS is designed for the current control of a Bid... more In this work, a neuro-fuzzy regulator based on ANFIS is designed for the current control of a Bidirectional Buck-Boost chopper battery charger. First, a PI regulator is used in the control loop. Data from the PI regulator is extracted and then used to train ANFIS. The performances of the two PI and neuro-fuzzy commands were evaluated under the MATLAB/SIMULINK environment. According to the simulation results, it was found that the neuro-fuzzy regulator ANFIS is more effective in improving the current response by reducing the response time. In conclusion, the neuro-fuzzy control gives a better performance compared to the PI control.
International journal of engineering research and technology, Jan 26, 2021
Renewable energy, particularly solar and wind, has an intermittent nature. For this purpose, a st... more Renewable energy, particularly solar and wind, has an intermittent nature. For this purpose, a storage module is recommended for a power generation system. This document shows the modeling of the lead-acid battery integrated in a hybrid system. The aim is to determine the internal characteristics of the battery and the influence of temperature and the influence of the charge and discharge time on one hand, and to visualize their behavior towards the various energy flows of the hybrid system on the other hand. In this study, we modelled the battery according to the CIEMAT model (Centro de Investigaciones Energéticas, Mediombientales y Technologicas). The system is composed of a photovoltaic and a wind sources. The power delivered by each source is controlled by incorporation of tracking control of the point of maximum power. Therefore, the hybrid set is optimized. The battery has been integrated into the system for energy storage, whose operation (charge and discharge) is managed by a supervision module. In the hybrid system, the operation of the battery generally depends on the energy input from the sources and the charge demand. The veracity of the CIEMAT model is shown on the simulation results that we performed using Matlab Simulink software.
Le présent travail a pour objectif de mettre en oeuvre la commande par Graphe Informationnel Caus... more Le présent travail a pour objectif de mettre en oeuvre la commande par Graphe Informationnel Causal (GIC). Des applications sur les entraînements réglés avec machine à courant continu à aimants permanents et avec machine asynchrone ont été abordées. L'utilisation de la machine à courant continu a été entamée vue qu'après découplage, la machine asynchrone se comporte comme deux machines à courant continu couplées électromécaniquement. De plus, la commande GIC avec compensation a été proposée. Les résultats de simulations ont montré que la méthode utilisant la commande GIC a donné de meilleurs résultats. Pour la machine asynchrone, la commande vectorielle utilisant le GIC donne en effet de meilleurs performances que la commande vectorielle classique : une variation au niveau du couple n'affecte ni le courant ni la vitesse pour la commande GIC alors que ce n'est pas le cas pour la commande classique. Mots clés— Machine asynchrone, découplage, commande vectorielle, graph...
This paper deals with a study of some controls applied on a Doubly-Fed Induction generator (DFIG)... more This paper deals with a study of some controls applied on a Doubly-Fed Induction generator (DFIG) dedicate in a chain of wind power conversion. Two methods are proposed: using a PI controller which synthesis is done by a new method called generalized method (GM) and using a polynomial controller RST one. The object is to apply these techniques to control the active and reactive powers generated by the DFIG. Simulations show that these controllers lead good results on tracking behavior, load disturbance rejection and show robustness following of variation parameters.
This paper deals with non line factor correction (PFC). This system presents two loops: the volta... more This paper deals with non line factor correction (PFC). This system presents two loops: the voltage loop and the current loop. A fuzzy PI controller is applied for the voltage loop and for the current loop, first a control hysteresis is used and then a control with Lyapunov algorithm. system. The total harmonic distortion (THD) is one criterion to apprec controls. Simulation results show that using these kinds of non linear controllers gives THD satisfying standard IEC 61000-3-2. It ensures moreover stability and good control velocity. Keywords: AC-DC boost converter, Fuzzy Logic, Lyapunov function, power factor, total harmonic distortion.
This paper deals with non linear controls for AC-DC converter with factor correction (PFC). This ... more This paper deals with non linear controls for AC-DC converter with factor correction (PFC). This system presents two loops: the voltage loop and the current loop. A fuzzy PI controller is applied for the voltage loop and for the current loop, first a control hysteresis is used and then a control with Lyapunov algorithm. system. The total harmonic distortion (THD) is one criterion to apprec controls. Simulation results show that using these kinds of non linear controllers gives THD satisfying standard IEC 61000-3-2. It ensures
Le présent travail étudie les performances des deux régulateurs usuels, PI et IP, appliqués aux s... more Le présent travail étudie les performances des deux régulateurs usuels, PI et IP, appliqués aux systèmes fondamentaux : premier et second ordre. Actuellement, le premier, bien que très simple, est largement rencontré dans les systèmes de correction de facteur de puissance et dans les commandes des machines électriques à courant alternatif en commande vectorielle avec orientation du flux. Les systèmes du second ordre sont aussi pris en compte permettant ainsi de compléter l'étude surtout au niveau de l'utilisation du régulateur IP. Les études ont montré que le système bouclé par un régulateur IP est moins rapide en poursuite mais a une réaction nettement meilleure en régulation que le système muni du régulateur PI. Mots clés Mots clés Mots clés Mots clés : Régulateurs PI et IP, synthèse, systèmes fondamentaux
This work deals with an Independent and Direct Rotor-Flux Oriented Control (IDRFOC) of series-con... more This work deals with an Independent and Direct Rotor-Flux Oriented Control (IDRFOC) of series-connected two-induction machines. This consists of connecting a six-phase motor with a three-phase one. The independence of flux-observers of both machine is predicted analytically from state equation. The Kalman observer is chosen to perform the estimation of the flux of each machine. Simulation results demonstrate the independence of flux observers and controls of both machines.
There are several techniques for maximum power point tracking (MPPT) used in system PV. The P&O a... more There are several techniques for maximum power point tracking (MPPT) used in system PV. The P&O algorithm is one of widely used among them. However, this technique presents some drawbacks: it is strongly related to the characteristic of the power according to the tension of the photovoltaic generator (GPV) and it presents sometimes oscillations around the maximum power point (MPP). This paper deals with a new method for its optimization by using fuzzy logic. Simulations results show that the new proposal is easy to be implemented and leads to better performances.
International Joint Conference on Computational Intelligence, 2015
This paper deals with a study of hybridization based on fuzzy logic controller and a polynomial R... more This paper deals with a study of hybridization based on fuzzy logic controller and a polynomial RST one. This new controller is applied on a Doubly-Fed Induction Generator (DFIG) dedicated in a chain of wind power conversion. These two types or controller have completely different structures: the RST controller uses directly the input and the output to form the command law and the fuzzy logic one needs the error and its variation as inputs. The new proposal consists first to make leave the a priori command from the RST structure and then to form the error and the difference of two consecutive error values for the fuzzy logic controller. The results of simulation show that this technique is realizable and leads to good performances on tracking test, disturbance rejection and robustness with respect of operating variation and parametric variation.
Abstract—This paper deals with a decoupled vector con-trol of two induction motors connected in s... more Abstract—This paper deals with a decoupled vector con-trol of two induction motors connected in series using mainly RST controller. This kind of controller offers further degrees of freedom to set the dynamic of the system. The first step is to fixe a reference model of the current and speed loops. A method of pole placement is detailed. Then, the three polynomial elements R, S, T of each controller will be synthesized by utilizing algebraic approaches and by solving the Diophante equation. In a first time, performance of RST controller is proven by simulation and experiment on the current and speed controls. Nonetheless, it is also possible to obtain better tracking, disturbance rejection and settling time by combining RST and IP controllers in practice. A special case is therefore treated where RST regulator is used for currents and IP controller is considered for speeds. This
This paper deals with the control of a AC-DC converter with power factor correction (Boost PFC). ... more This paper deals with the control of a AC-DC converter with power factor correction (Boost PFC). The polynomial controller named RST by the three polynomials which constitute it, R(z), T(z) and S(z), is applied to the loop voltage and the loop current is controlled by hysteresis. This kind of controller generalizes the structure of the PID one. Simulation and experimental results show that modelling the open voltage loop by a first order system gives good results supported by a THD satisfying standard IEC even the system presents nonlinearities. Teaching and industrial applications are taken into account: it is the reason of using Labview with the peripheral NI 6009.
International Review of Electrical Engineering-iree, 2011
This paper deals with a decoupled vector control of two induction motors connected in series usin... more This paper deals with a decoupled vector control of two induction motors connected in series using mainly RST controller. This kind of controller offers further degrees of freedom to set the dynamic of the system. The first step is to fixe a reference model of the current and speed loops. A method of pole placement is detailed. Then, the three polynomial elements R, S, T of each controller will be synthesized by utilizing algebraic approaches and by solving the Diophante equation. In a first time, performance of RST controller is proven by simulation and experiment on the current and speed controls. Nonetheless, it is also possible to obtain better tracking, disturbance rejection and settling time by combining RST and IP controllers in practice. A special case is therefore treated where RST regulator is used for currents and IP controller is considered for speeds. This case will be experimentally demonstrated.
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Papers by Jean RAZAFINJAKA