The paper presents the complete modeling and control strategy of variable speed wind turbine system (WTS) driven doubly fed induction generators (DFIG). A back-to-back converter is employed for the power conversion exchanged between DFIG and grid. The wind turbine is operated at the maximum power point tracking (MPPT) mode its maximum efficiency. Direct power control (DPC) based on selecting of the appropriate rotor voltage vectors and the errors of the active and reactive power, the control strategy of rotor side converter combines the technique of MPPT and direct power control. In the control system of the grid side converter the direct power control has been used to maintain a constant DC-Link voltage, and the reactive power is set to 0. Simulations results using MATLAB/SIMULINK are presented and discussed on a 1.5MW DFIG wind generation system demonstrate the effectiveness of the proposed control.
Keyword:Back-to-back converter DFIG DPC MPPT WTS
Copyright © 2017 Institute of Advanced Engineering and Science.All rights reserved.
Corresponding Author:Senani Fawzi, Laboratoire de l'Electrotechnique de Constantine (LEC), Faculté des Sciences de la Technologie, Université des frères Mentouri de Constantine 1, Ain el-bey 25000 Constantine, Algerie. Email: senani.fouzi@gmail.com
INTRODUCTIONActually, there are several sources of renewable energy, wind energy, hydropower, geothermal energy, biomass, biofuel and solar energy [1]. Wind and solar electric power generation systems are popular renewable energy resources [2]. The wind energy conversion system (WECS) has been considered to be one of the main energy resources are growing rapidly among the other renewable generation power technologies due to its freely available, clean and renewable character [3][4][5]. Wind energy conversion systems are basically divided into two fixed and variable speed.Variable speed WECS have been many advantages: operation at maximized power capture over a wide range of wind speeds, reduced mechanical stresses imposed on the turbine, and improved power quality compared with fixed speed WECS[5], [6]. The variable speed WECS using the DFIGs are suitable and promising for application in wind energy. The DFIG is particularly employed for high-power applications, due to the lower converters cost and lower power losses [7].The WECS based DFIGs control comprises both the rotor side converter (RSC) combines the technique of MPPT and grid side converter (GSC) controllers so that the RSC controls stator active and reactive powers and the GSC regulates dc-link voltage as well as generates an independent reactive power that is injected into the grid [7], [8], for RSC traditionally the vector control (VC) based on a stator flux orientation [7], [9] using proportional-integral (PI) controllers [10], However, it has some disadvantages, such as its dependence on the machine parameters variation, that its performance largely depends on the tuning of the PI parameters, must be optimally tuned to ensure the system stability within the whole operating range