Farid Bouchafaa

Modeling and simulation of a gird connected PV generation system with MPPT fuzzy logic control

This paper presents a simulation model of the electric part of a grid connected photovoltaic generation system. The model contains a detailed representation of the main components of the system that are the solar array, and the grid side inverter multilevel inverter Neutral Point Clamped (NPC) VSI. In order to extract the maximum amount of from the photovoltaic generator, we propose an intelligent control method for the maximum power point tracking (MPPT) of a photovoltaic system under variable temperature and insulation conditions. This method uses a fuzzy logic controller. As part of our work, we will focus on voltage inverter at three levels to NPC structure. The latter can increase the voltage supplied to the load (network) through their topology. Thus, they can generate more voltage sinusoidal possible and improve the total harmonic distortion through the high voltage levels provided by the structure of this new converter. The grid interface inverter transfers the energy drawn from the PV module into the grid by keeping common dc voltage constant. The PQ control approach has been presented for the multilevel inverter. The simulation results under Matlab/Simulink show the control performance and dynamic behaviour of grid connected photovoltaic system.

Modelling and control of a power electronic cascade for the multi‐DC bus supply

Purpose – The purpose of this paper is to describe the control and regulation of input DC voltages of nine‐level neutral point clamping (NPC) voltage source inverter (VSI).Design/methodology/approach – The analysis and simulation of a cascade made up of three‐phase five‐level PWM rectifier‐nine levels NPC VSI are treated. This cascade is used to feed a permanent magnet synchronous machine (PMSM) drive. First, the five‐level PWM rectifier is presented. Then a topology of nine‐level NPC VSI and the associated PWM control strategy are described. In order to discard the problem of DC link voltage fluctuations, a clamping bridge with a PI regulation has been added to the cascade. Then a field‐oriented control strategy has been implemented in the PMSM.Findings – The obtained results are full of promise to use the inverter in high voltage and great power applications such as electric naval propulsion systems.Originality/value – The application of the proposed feedback control algorithm to the studied cascade off...

Enslavement and control of the multi DC-bus link voltages using adaptive fuzzy

Voltage-source multilevel inverters have become very attractive for power industries in power electronics applications during last years. The main purposes that have led to the development of the studies about multilevel inverters are the generation of output voltage signals with low harmonic distortion; the reduction of switching frequency. A serious constraint in a multilevel inverter is the capacitor voltage-balancing problem. The unbalance of different DC voltage sources of five-level neutral point clamping (NPC) voltage source inverter (VSI) constitutes the major limitation for the use of this new power converter. In order to stabilize these DC voltages, we propose in this paper to study the cascade constituted by three phases five-level PWM rectifier, a clamping bridge and five-level NPC (VSI). In the first part, we present a topology of five-level NPC VSI, then they propose a model of this converter and an optimal PWM strategy to control it using four bipolar carriers. Then in the second part, we study a five-level PWM rectifier, which is controlled by a multiband hysteresis strategy. In the last part of this paper, the authors study shows particularly the problem of the stability of the multi DC voltages of the inverter and its consequence on the performances of the induction motors (IM). Then, we propose a solution to the problem by employed closed loop regulation using PI regulator type fuzzy logic controller (FLC). The results obtained with this solution confirm the good performances of the proposed solution, and promise to use the inverter in high voltage and great power applications as electrical traction.

Analysis and simulation of a multilevel inverter converter NPC Cascade

This paper describes the control and regulation of input DC voltages of nine-level NPC voltage source inverter. The analysis and simulation of a cascade constituted by three phases five-level PWM rectifier-nine levels NPC voltage source inverter (VSI). In the first part, the authors present the five-level PWM rectifier. After, we present a topology of nine levels NPC VSI for then we propose a model of this inverter and the SVPWM strategy which uses eight bipolar carriers to control it. The study of this cascade shows that the input DC voltages of the inverter are not stable and not equals. To remedy to this problem, the authors propose to introduce in the cascade a clamping bridge and regulation using PI regulator. In the second part, we study speed control of the Permanent magnet synchronous machine (PMSM) by using the field oriented control. The results obtained are full of promise to use the inverter in high voltage and great power applications as electrical traction.

Novel algebraic PWM strategy of a multilevel Voltage Source Inverter

In this paper, the authorpsilas present one algorithm of algebraic PWM strategy for seven-level neutral point clamping (NPC) voltage source inverter (VSI) is presented. This algorithm uses a control model of the inverter developed previously by the authors. In the first part, we develop a working model of this inverter, without presumption on its control, by using the connection functions of this converter. In the second part the control models of this converter by using respectively instantaneous and generating connection functions are reviewed. In the last part, one algebraic PWM control strategy of the inverter is proposed. The obtained results are full of promise to use this digital strategy to control seven-level NPC VSI used in high voltage, high power applications as electrical traction.

Contribution to the Control Power of a Wind System with a Storage System

Here we present two techniques of commands: DTC (direct torque control) and DPC (direct power control), which are applied to the system for converting wind energy with storage. The wind generator used is based on a double-fed induction generator (DFIG), in which the stator is connected directly to the network and the rotor is connected to the network through the power converter. The Flywheel Energy Storage System (FESS), which is based on a flywheel, an induction machine (IM), and an electronic power converter, is associated with the wind generator via the DC bus. The two converters’ side DFIGs and the FESS are controlled by DTC. The three-level converter side electricity grid, which ensures constant DC bus voltage, is controlled by the DPC. The main goal of the direct control of these systems is to eliminate the block of pulse width modulation and loops by regulating internally controlled variables. The use of a switching table makes the system more efficient from a technical rather than an economic point of view.

Energy optimization for a wind DFIG with flywheel energy storage

The type of distributed generation unit that is the subject of this paper relates to renewable energy sources, especially wind power. The wind generator used is based on a double fed induction Generator (DFIG). The stator of the DFIG is connected directly to the network and the rotor is connected to the network through the power converter with three levels. The objective of this work is to study the association a Flywheel Energy Storage System (FESS) in wind generator. This system is used to improve the quality of electricity provided by wind generator. It is composed of a flywheel; an induction machine (IM) and a power electronic converter. A maximum power tracking technique « Maximum Power Point Tracking » (MPPT) and a strategy for controlling the pitch angle is presented. The model of the complete system is developed in Matlab/Simulink environment / to analyze the results from simulation the integration of wind chain to networks.

Advanced control for wind energy conversion systems with flywheel storage dedicated to improving the quality of energy

In this article, we present two techniques of commands DTC (direct torque control) and DPC (direct power control), applied to in the system for converting wind energy with storage. The use of the wind generator is based on a double fed induction Generator (DFIG) where the stator is connected directly to the network and the rotor is connected to the network through the power converter. The Flywheel Energy Storage System (FESS) based on a flywheel, an induction machine (IM) and an electronic power converter is associated with the wind generator via the DC bus. The two converters side DFIG and the (FESS) are controlled by the DTC. The three-level converter side electricity grid which ensures constant DC bus voltage is controlled by the DPC. In the literature, this control strategy has been frequently used for the two levels converter. The direct control of these systems has purpose to eliminate the block of pulse width modulation and loops of regulations internal controlled variables. The use of switching table makes the system more efficient from the technical and economic view.

FEEDBACK LOOP CONTROL STRATEGIES OF THE MULTI DC BUS LINK VOLTAGES USING ADAPTIVE FUZZY LOGIC CONTROL

Voltage source multilevel inverters have become very attractive for power industries in power electronics applications during last years. The main purposes that have led to the development of the studies about multilevel inverters are the generation of output voltage signals with low harmonic distortion; the reduction of switching frequency. A serious constraint in a multilevel inverter is the capacitor voltage-balancing problem. The unbalance of different DC voltage sources of five-level neutral point clamping (NPC) voltage source inverter (VSI) constitutes the major limitation for the use of this new power converter. In order to stabilize these DC voltages, we propose in this paper to study the cascade constituted by three phases five-level PWM rectifier, a clamping bridge and five-level NPC (VSI). In the first part, we present a topology of five-level NPC VSI, and then they propose a model of this converter and an optimal PWM strategy to control it using four bipolar carriers. Then in the second part, we study a five-level PWM rectifier, which is controlled by a multiband hysteresis strategy. In the last part of this paper, the authors study shows particularly the problem of the stability of the multi DC voltages of the inverter and its consequence on the performances of the induction motors (IM). Then, we propose a solution to the problem by employed closed loop regulation using PI regulator type fuzzy logic controller (FLC). The results obtained with this solution confirm the good performances of the proposed solution, and promise to use the inverter in high voltage and great power applications as electrical traction.

Fuzzy logic control for a speed of a flywheel energy storage system associated the wind generator

The type of distributed generation unit that is the subject of this article relates to renewable energy sources, especially wind power. The wind generator used is based on a double fed induction Generator (DFIG). The stator of the DFIG is connected directly to the network and the rotor is connected to the network through the power converter. The objective of this work is to study the association a Flywheel Energy Storage System (FESS) in wind generator. This system is used to improve the quality of electricity provided by wind generator. It is composed of a flywheel; an asynchronous machine has cage and a power electronic converter. The control of FESS proposed in this paper and velocity using a fuzzy logic controller is validated by simulations is compared with results obtained PI. The results are presented and discussed.