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Grid Connected Doubly Fed Induction Generator Wind Energy Conversion System Using Fuzzy Controller
Pooja Dewangan,,Prof. S. D. Bharti
International Journal of Innovative Technology and Exploring Engineering , 2013,
Abstract: This paper presents the simulation and control of a grid connected doubly-fed induction generator driven by a variable speed wind turbine. Fuzzy logic control strategy is applied to doubly fed induction generator (DFIG). The Matlab/Simulink/SimPowerSystems software is used to Simulate all the components of grid connected doubly fed induction generator (DFIG)-based wind power conversion system (WPCS). DFIG consists of a common wound rotor induction generator with slip ring and a back to back voltage source convertor. Fuzzy logic controller is applied to both grid side convertor (GSC) for dc link voltage control and rotor side convertor (RSC) for active and reactive power control. Coordinated control of the grid- and rotor side converters (GSC and RSC, respectively) is presented in the positive synchronous reference. Use of DFIG in wind turbine is widely spreading due to its control over DC voltage and active and reactive power. Conventional dq axis current control using voltage source converters for both the grid side and the rotor side of the DFIG are analyzed and simulated. Simulation results prove the excellent performance of fuzzy control unit as improving power quality and stability of wind turbine.
Fuzzy sliding mode controller for servo tracking control in precision machine tools

XIE Xu-hui,DAI Yi-fan,LI Sheng-yi,

控制理论与应用 , 2003,
Abstract: Detail research was given to servo tracking controller design that utilized the sliding mode control theory in order to achieve robust tracking performance in precision machine tools subject to parameter variations and external disturbance. A type of fuzzy sliding mode controller was presented by incorporating the fuzzy logic with the sliding mode control to alleviate the chattering of the sliding mode controller. Experimental results showed that this fuzzy sliding mode controller had more robustness and better tracking performance than the sliding mode controller and PID.
Design and Implement a Digital H∞ Robust Controller for a MW-Class PMSG-Based Grid-Interactive Wind Energy Conversion System  [PDF]
Abdul Motin Howlader,Naomitsu Urasaki,Atsushi Yona,Tomonobu Senjyu,Ahmed Yousuf Saber
Energies , 2013, DOI: 10.3390/en6042084
Abstract: A digital H∞ controller for a permanent magnet synchronous generator (PMSG) based wind energy conversion system (WECS) is presented. Wind energy is an uncertain fluctuating resource which requires a tight control management. So, it is still an exigent task for the control design engineers. The conventional proportional-integral (PI) control is not ideal during high turbulence wind velocities, and the nonlinear behavior of the power converters. These are raising interest towards the robust control concepts. The robust design is to find a controller, for a given system, such that the closed-loop system becomes robust that assurance high-integrity and fault tolerant control system, robust H∞ control theory has befallen a standard design method of choice over the past two decades in industrial control applications. The robust H∞ control theory is also gaining eminence in the WECS. Due to the implementation complexity for the continuous H∞ controller, and availability of the high speedy micro-controllers, the design of a sample-data or a digital H∞ controller is very important for the realistic implementation. But there isn’t a single research to evaluate the performance of the digital H∞ controller for the WECS. In this paper, the proposed digital H∞ controller schemes comprise for the both generator and grid interactive power converters, and the control performances are compared with the conventional PI controller and the fuzzy controller. Simulation results confirm the efficacy of the proposed method Energies 2013, 6 2085 which are ensured the WECS stabilities, mitigate shaft stress, and improving the DC-link voltage and output power qualities.
Avoidance High-Frequency Chattering Second-Order Sliding Mode Controller Design: Buck Converter in Wind Power System  [PDF]
Yigeng Huangfu,Ruiqing Ma,Abdellatif Miraoui
International Journal of Antennas and Propagation , 2012, DOI: 10.1155/2012/176830
Abstract: This paper mainly discussed a method of high-frequency second-order sliding mode control for Buck converter in wind power systems. Because the wind energy of nature is always unpredictable and intermittent, the robust control such as sliding mode control is adopted in past literatures. In order to remove the high frequency chattering problem when the traditional sliding mode achieves convergence, the second order sliding mode algorithm is reviewed firstly. Meanwhile, the Buck converter taken as a step-down converter is usually adopted in wind power system, because of its simple structure and good linearity. Under those conditions, the second order sliding mode controller is designed based on Buck converter, especially in high-power wind generation system. The experimental results illustrate that the theory of second order sliding mode can be used in high-power Buck converter. It provides one novel avoidance high frequency chattering method for the technology development of new energy generation system. 1. Introduction Conventional energy resources may run out of in the following few decades, especially from fossil energy could lead to the energy shortage in the world. Moreover, the energy consumption is increased dramatically in recent years. The renewable energy sources, such as solar, wind, or ocean wave energy, are considered to be the future energy solutions. Thanks to the extensive research in renewable energy field, those energies can be exploited more and more easily and properly [1–3]. Among the renewable resources, the wind energy is gaining greater visibility during the last several years as a convenient and promising energy source in the future [4]. The application of wind energy is divided into two aspects. One is off-grid wind power station with the battery as energy storage component, and the other is connect-to-grid wind turbine. In many applications, such as small villages or islands power station, the off-grid wind power generation system provides an excellent energy solution. The key problem of this kind of energy production systems is that they are unstable energy sources due to their primary source in nature. Thus, an energy storage component is usually added to form a hybrid energy system. In such a system, the suitable power converter plays an important role in energy conversion and management system. Generally speaking, these converters should be adaptive for wider wind speed range in order to improve the system performance. In a wind generation system, two types of converter can be usually found: a primary AC/DC converter
GA-Based Fuzzy Sliding Mode Controller for Nonlinear Systems  [PDF]
P. C. Chen,C. W. Chen,W. L. Chiang
Mathematical Problems in Engineering , 2008, DOI: 10.1155/2008/325859
Abstract: Generally, the greatest difficulty encountered when designing a fuzzy sliding mode controller (FSMC) or an adaptive fuzzy sliding mode controller (AFSMC) capable of rapidly and efficiently controlling complex and nonlinear systems is how to select the most appropriate initial values for the parameter vector. In this paper, we describe a method of stability analysis for a GA-based reference adaptive fuzzy sliding model controller capable of handling these types of problems for a nonlinear system. First, we approximate and describe an uncertain and nonlinear plant for the tracking of a reference trajectory via a fuzzy model incorporating fuzzy logic control rules. Next, the initial values of the consequent parameter vector are decided via a genetic algorithm. After this, an adaptive fuzzy sliding model controller, designed to simultaneously stabilize and control the system, is derived. The stability of the nonlinear system is ensured by the derivation of the stability criterion based upon Lyapunov's direct method. Finally, an example, a numerical simulation, is provided to demonstrate the control methodology.
A New Fuzzy Sliding Mode Controller with PID Sliding Surface for Underwater Manipulators  [PDF]
Hossein Nejatbakhsh Esfahani,Vahid Azimirad
International Journal of Mechatronics, Electrical and Computer Technology , 2013,
Abstract: Design of an accurate and robust controller is challenging topic in underwater manipulator control. This is due to hydrodynamic disturbances in underwater environment. In this paper a sliding mode control (SMC) included a PID sliding surface and fuzzy tunable gain is designed. In this proposed controller robustness property of SMC and fast response of PID are incorporated with fuzzy rules to reduce error tracking. In the control law, for remove of chattering, the exponential function is used. And also system is analyzed in terms of stability by direct lyapunov method. By tuning gains with fuzzy logic, the proposed controller does not require an accurate model of underwater manipulator dynamics. Hence the modeling and simulation studies are done for an underwater manipulator to verify the effectiveness of the proposed method. Both new proposed controller and conventional SMC are simulated. The results of simulation show the high performance of proposed controller in comparison to conventional SMC.
Designing of Proportional Sliding Mode Controller for Linear One Stage Inverted Pendulum  [cached]
Anirban Banrejee,M. J. Nigam
Advances in Electrical and Electronic Engineering , 2011,
Abstract: The control of Inverted Pendulum (IP) is a hugely complex task. A great deal of nonlinearity is present inherently and as well as affected by the surrounding external conditions. The sliding mode controller (SMC) is very robust inherently. It is used in this paper to control the IP. This paper examines the designing of sliding mode controller (SMC) for a linear inverted pendulum (IP). The paper highlights the important features of the sliding mode and also throws ample lights on the designing guidelines. The paper puts special impetus on the mathematical modeling of the controller. The robustness of the design of SMC with proportional control is amply displayed with the help of simple mathematics. It gives rise to a controller which can control a highly nonlinear system like IP quite efficiently. The performance of the SMC is compared with fuzzy and PID controller. The edge this controller poses is the key aspect of this paper. External disturbances and internal inaccuracies are also introduced to the system to bring out the robustness of the controller to the fore. Background on sliding mode and the pendulum are provided. Simulation results are displayed in a vivid manner and explained suitably.
Designing Flexible Neuro-Fuzzy System Based on Sliding Mode Controller for Magnetic Levitation Systems
Zahra Mohammadi,Mohammad Teshnehlab,Mahdi Aliyari Shoorehdeli
International Journal of Computer Science Issues , 2011,
Abstract: This study presents a novel controller of magnetic levitation system by using new neuro-fuzzy structures which called flexible neuro-fuzzy systems. In this type of controller we use sliding mode control with neuro-fuzzy to eliminate the Jacobian of plant. At first, we control magnetic levitation system with Mamdanitype neuro-fuzzy systems and logical-type neuro-fuzzy systems separately and then we use two types of flexible neuro-fuzzy systems as controllers. Basic flexible OR-type neuro-fuzzy inference system and basic compromise AND-type neuro-fuzzy inference system are two new flexible neuro-fuzzy controllers which structure of fuzzy inference system (Mamdani or logical) is determined in the learning process. We can investigate with these two types of controllers which of the Mamdani or logical type systems has better performance for control of this plant. Finally we compare performance of these controllers with sliding mode controller and RBF sliding mode controller.
Sliding Controller of Switched Reluctance Motor
Ahmed TAHOUR,Abdelkader MEROUFEL,Hamza ABID,Abdel Ghani AISSAOUI
Leonardo Electronic Journal of Practices and Technologies , 2008,
Abstract: This paper presents an application of sliding mode control for switched reluctance motor (SRM) speed. The sliding mode technique finds its stronger justification in the utilization of a robust control law to model uncertainties. A sliding mode controller of the motor speed is then designed and simulated. Digital simulation results shows that the designed sliding speed controller realises a good dynamic behaviour of the motor, a perfect speed tracking with no overshoot and a good rejection of impact loads disturbance. The results of applying the sliding mode controller to a SRM give best performances and high robustness than those obtained by the application of a conventional controller (PI).
A neuro-fuzzy-sliding mode controller using nonlinear sliding surface applied to the coupled tanks system
A Neuro-fuzzy-sliding Mode Controller Using Nonlinear Sliding Surface Applied to the Coupled Tanks System

Ahcene Boubakir,Fares Boudjema,Salim Labiod,

国际自动化与计算杂志 , 2009,
Abstract: The aim of this paper is to develop a neuro-fuzzy-sliding mode controller (NFSMC) with a nonlinear sliding surface for a coupled tank system. The main purpose is to eliminate the chattering phenomenon and to overcome the problem of the equivalent control computation. A first-order nonlinear sliding surface is presented, on which the developed sliding mode controller (SMC) is based. Mathematical proof for the stability and convergence of the system is presented. In order to reduce the chattering in SMC, a fixed boundary layer around the switch surface is used. Within the boundary layer, where the fuzzy logic control is applied, the chattering phenomenon, which is inherent in a sliding mode control, is avoided by smoothing the switch signal. Outside the boundary, the sliding mode control is applied to drive the system states into the boundary layer. Moreover, to compute the equivalent controller, a feed-forward neural network (NN) is used. The weights of the net are updated such that the corrective control term of the NFSMC goes to zero. Then, this NN also alleviates the chattering phenomenon because a big gain in the corrective control term produces a more serious chattering than a small gain. Experimental studies carried out on a coupled tank system indicate that the proposed approach is good for control applications.
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