Improved control strategy of DFIG-based wind turbines using direct torque and direct power control techniques

This paper presents different control strategies for a variable-speed wind energy conversion system (WECS), based on a doubly fed induction generator. Direct Torque Control (DTC) with Space-Vector Modulation is used on the rotor side converter. This control method is known to reduce the fluctuations of the torque and flux at low speeds in contrast to the classical DTC, where the frequency of switching is uncontrollable. The reference for torque is obtained from the maximum power point tracking technique of the wind turbine. For the grid-side converter, a fuzzy direct power control is proposed for the control of the instantaneous active and reactive power. Simulation results of the WECS are presented to compare the performance of the proposed and classical control approaches.Peer reviewedFinal Accepted Versio

Shoot-Through Control-Based Space Vector Modulation Approach for a Modified Z-Source NPC Power Inverter

Z-source Neutral Point Clamped (NPC) in-verter is a converter topology that combines the benefits of both the impedance network by storing temporary energy released to the load for voltage boosting and NPC inverter by guaranteeing lower Total Harmonic Distor-tions (THDs) and reducing voltage stresses of switching devices. In this context, this paper deals with a modified three-level Z-source NPC inverter topology with simplified command to generate shoot-through states and reduce switching losses. For this reason, an extra power switch Insulated Gate Bipolar Transistor (IGBT) is added to insert shoot-through, thus eliminating the need for full-shoot-through on any of the three branches of the inverter. On the other hand, a modified Space Vec-tor Modulation (SVM) strategy is proposed. This gives a number of benefits, both in terms of implementation and harmonic performance. Effectiveness of the proposed topology is verified through simulations using Matlab toolbox Simulation and laboratory experimen

Stator powers controller with rotor currents sensor less, using sliding mode of WECS based on DFIG and matrix converter

International audienc

Contribution des convertisseurs multiniveaux au raccordement de la production d'origine éolienne sur un réseau électrique

LILLE1-BU (590092102) / SudocVILLENEUVE D'ASCQ-ECLI (590092307) / SudocSudocFranceF

An effective hybrid maximum power point tracker of photovoltaic arrays for complex partial shading conditions

This paper proposes an improved maximum power point tracker (MPPT) for photovoltaic (PV) system. The scheme is a hybrid between the adaptive perturb and observe and particle swarm optimization (PSO). The algorithm incorporates the search-skip-judge (SSJ) mechanism to minimize the region within the P-V curve to be searched by the PSO. Furthermore, the PSO performance is enhanced by ensuring that the regions that have been previously explored (by other particle) will not be searched again by (another particle). Thus, the unnecessary movement of particles is minimized-leading to faster convergence. The proposed method is evaluated against four well-known MPPT techniques, namely the modified incremental conductance, the original version of SSJ, the modified cuckoo search, and the hybrid PSO. In addition, an experimental prototype, which is based on PV array simulator is used to verify the simulation. The competing algorithms are tested with a buck-boost converter, driven by the TMS320F240 DSP on the dSPACE DS1104 platform. It was found that the proposed scheme converges to the global maximum power point (GMPP) most rapidly and the GMPP tracking is guaranteed even under complex partial shading conditions

Feedback control of three-level PWM rectifier : application to the stabilization of DC voltages of five-level NPC active power filter

One of the most important drawbacks of the three phases five-level NPC (Neutral Point Clamped) Active Power Filter (APF) is the neutral point balance. As the consequence, the capacitors voltages of the input DC bus of the APF are not equal which constitutes the major limitation for the use of this power converter. In order to stabilize these DC voltages, it is proposed in this paper to study the cascade constituted by three phases three-level PWM rectifier-clamping bridge filter-five-level NPC APF. In the first part, the authors present a topology of five-level NPC Voltage Source Inverter (VSI), and then, they propose a model of this converter and its PWM control strategy. In the second part, the modeling and control of three-level PWM current rectifier is presented. In the third part, to remedy to instability problem of the input capacitors DC voltages of the APF, the authors propose feedback control of the three-level PWM rectifier followed by clamping bridge filter. After that, the sliding mode regulator used to control the active filter is developed. The obtained results are full of promise to use this topology of APF in high voltage and high power application