Induction machines sensors-less wind generator with integrated intelligent maximum power point tracking and electric losses minimisation technique

This study presents a high-performance wind generation system with induction machine (IM), specifically devised with the target of maximising the efficiency of the electromechanical conversion, and contemporary minimising the number of the system sensors and their cost. To this aim, the control system has been integrated, from one side, with an intelligent maximum power point tracking (MPPT) technique, so to make the generator track the power available in the wind, from the other side with techniques for the minimisation of the electrical losses (ELMT). Particularly, the power converters' switching losses have been reduced adopting a discontinuous pulsewidth modulation, while the IM overall losses have been reduced by a suitable electric losses minimisation technique. Contemporary, to reduce costs and increase the reliability of the system, the system has been devised as a fully sensors-less generation unit, meaning that both the wind speed and the machine speed sensors are not present. The anemometer has been substituted by the wind speed estimator integrated in the MPPT, based on the growing neural gas (GNG) network. The encoder has been substituted with an intelligent IM speed estimator, the so called MCA EXIN + reduced order observer (ROO). The performance of the adopted technique has been verified experimentally on a suitably devised test set-up

Model simplification and optimization of a passive wind turbine generator

In this paper, the design of a "low cost full passive structure" of wind turbine system without active electronic part (power and control) is investigated. The efficiency of such device can be obtained only if the design parameters are mutually adapted through an optimization design approach. For this purpose, sizing and simulating models are developed to characterize the behavior and the efficiency of the wind turbine system. A model simplification approach is presented, allowing the reduction of computational times and the investigation of multiple Pareto-optimal solutions with a multiobjective genetic algorithm. Results show that the optimized wind turbine configurations are capable of matching very closely the behavior of active wind turbine systems which operate at optimal wind powers by using a MPPT control device

A Review of Control Techniques for Wind Energy Conversion System

Wind energy is the most efficient and advanced form of renewable energy (RE) in recent decades, and an effective controller is required to regulate the power generated by wind energy. This study provides an overview of state-of-the-art control strategies for wind energy conversion systems (WECS). Studies on the pitch angle controller, the maximum power point tracking (MPPT) controller, the machine side controller (MSC), and the grid side controller (GSC) are reviewed and discussed. Related works are analyzed, including evolution, software used, input and output parameters, specifications, merits, and limitations of different control techniques. The analysis shows that better performance can be obtained by the adaptive and soft-computing based pitch angle controller and MPPT controller, the field-oriented control for MSC, and the voltage-oriented control for GSC. This study provides an appropriate benchmark for further wind energy research

Fuzzy model based multivariable predictive control design for rapid and efficient speed-sensorless maximum power extraction of renewable wind generators

Introduction. A wind energy conversion system needs a maximum power point tracking algorithm. In the literature, several works have interested in the search for a maximum power point wind energy conversion system. Generally, their goals are to optimize the mechanical rotation or the generator torque and the direct current or the duty cycle switchers. The power output of a wind energy conversion system depends on the accuracy of the maximum power tracking controller, as wind speed changes constantly throughout the day. Maximum power point tracking systems that do not require mechanical sensors to measure the wind speed offer several advantages over systems using mechanical sensors. The novelty. The proposed work introduces an intelligent maximum power point tracking technique based on a fuzzy model and multivariable predictive controller to extract the maximum energy for a small-scale wind energy conversion system coupled to the electrical network. The suggested algorithm does not need the measurement of the wind velocity or the knowledge of turbine parameters. Purpose. Building an intelligent maximum power point tracking algorithm that does not use mechanical sensors to measure the wind speed and extracts the maximum possible power from the wind generator, and is simple and easy to implement. Methods. In this control approach, a fuzzy system is mainly utilized to generate the reference DC-current corresponding to the maximum power point based on the changes in the DC-power and the rectified DC-voltage. In contrast, the fuzzy model-based multivariable predictive regulator follows the resultant reference current with minimum steady-state error. The significant issues of the suggested maximum power point tracking method, such as the detailed design process and implementation of the two controllers, have been thoroughly investigated and presented. The considered maximum power point tracking approach has been applied to a wind system driving a 5 kW permanent magnet synchronous generator in variable speed mode through the simulation tests. Practical value. A practical implementation has been executed on a 5 kW test bench consisting of a dSPACEds1104 controller board, permanent magnet synchronous generator, and DC-motor drives to confirm the simulation results. Comparative experimental results under varying wind speed have confirmed the achievable significant performance enhancements on the maximum wind energy generation and overall system response by using the suggested control method compared with a traditional proportional integral maximum power point tracking controller.Вступ. Система перетворення енергії вітру потребує алгоритму відстеження точки максимальної потужності. У літературі є кілька робіт, присвячених пошуку системи перетворення енергії вітру із точкою максимальної потужності. Як правило, їх метою є оптимізація механічного обертання або моменту, що крутить, генератора і перемикачів постійного струму або робочого циклу. Вихідна потужність системи перетворення енергії вітру залежить від точності контролера стеження за максимальною потужністю, оскільки швидкість вітру постійно змінюється протягом дня. Системи стеження за точками з максимальною потужністю, яким не потрібні механічні датчики для вимірювання швидкості вітру, мають ряд переваг у порівнянні з системами, що використовують механічні датчики. Новизна. Пропонована робота представляє інтелектуальний метод відстеження точки максимальної потужності, заснований на нечіткій моделі та багатопараметричному прогнозуючому контролері, для отримання максимальної енергії для маломасштабної системи перетворення енергії вітру, підключеної до електричної мережі. Пропонований алгоритм не вимагає вимірювання швидкості вітру або знання параметрів турбіни. Мета. Побудова інтелектуального алгоритму відстеження точки максимальної потужності, який не використовує механічні датчики для вимірювання швидкості вітру та витягує максимально можливу потужність з вітрогенератора, а також простий та зручний у реалізації. Методи. У цьому підході до управління нечітка система в основному використовується для генерування еталонного постійного струму, що відповідає точці максимальної потужності, на основі змін потужності постійного струму та постійної випрямленої напруги. Навпаки, багатопараметричний прогнозуючий регулятор на основі нечіткої моделі слідує за результуючим еталонним струмом з мінімальною помилкою, що встановилася. Істотні проблеми запропонованого методу відстеження точки максимальної потужності, такі як процес детального проектування та реалізація двох контролерів, були ретельно досліджені та представлені. Розглянутий підхід до відстеження точки максимальної потужності був застосований до вітрової системи, що приводить у дію синхронний генератор з постійними магнітами потужністю 5 кВт у режимі змінної швидкості за допомогою моделювання. Практична цінність. Для підтвердження результатів моделювання було виконано практичну реалізацію на випробувальному стенді потужністю 5 кВт, що складається з плати контролера dSPACEds1104, синхронного генератора з постійними магнітами та електроприводів з двигунами постійного струму. Порівняльні експериментальні результати при різній швидкості вітру підтвердили значні поліпшення продуктивності з максимального вироблення енергії вітру і загального відгуку системи при використанні запропонованого методу управління в порівнянні з традиційним пропорційно-інтегральним контролером спостереження за точкою максимальної потужності

A Maximum Power Point Tracking Control Algorithms for a PMSG‐based WECS for Isolated Applications: Critical Review

This chapter deals with a comprehensive overview study of the direct‐driven (DD) permanent magnet synchronous generator (PMSG) for wind‐energy generation system for stand‐alone applications. The dynamic model of PMSG is presented, and different maximum power point tracking (MPPT) algorithms have been realized in the aim to compare their performance. A comparison of performances of the conventional P&O MPPT and the fuzzy logic P&O (FLC P&O) MPPT is presented. Control technique for the presented system is presented and analyzed for the generator side converter. The simulation results carried out using Matlab/Simulink software show the effectiveness of the wind turbine control system

MPPT Control Methods in Wind Energy Conversion Systems

Wind energy conversion systems have been attracting wide attention as a renewable energy source due to depleting fossil fuel reserves and environmental concerns as a direct consequence of using fossil fuel and nuclear energy sources. Wind energy, even though abundant, varies continually as wind speed changes throughout the day. The amount of power output from a wind energy conversion system (WECS) depends upon the accuracy with which the peak power points are tracked by the maximum power point tracking (MPPT) controller of the WECS control system irrespective of the type of generator used. This study provides a review of past and present MPPT controllers used for extracting maximum power from the WECS using permanent magnet synchronous generators (PMSG), squirrel cage induction generators (SCIG) and doubly fed induction generator (DFIG). These controllers can be classified into three main control methods, namely tip speed ratio (TSR) control, power signal feedback (PSF) control and hill-climb search (HCS) control. The chapter starts with a brief background of wind energy conversion systems. Then, main MPPT control methods are presented, after which, MPPT controllers used for extracting maximum possible power in WECS are presented

Addendum of 2MW Wind Turbine to A Power with Directly-Driven Permanent Magnet Generation System

In recent years, wind turbine has become an acceptable alternative energy generation, because of the environmental and economic benefits. Notwithstanding more research works still need to be done to reduce wind turbine installation complexity, enhance profitability and reliability especially in developing countries like Nigeria. This paper presents the modeling and analysis of a 2MW variable-speed directly-driven permanent magnet synchronous generator (PMSG), Wind energy conversion system (WECS). The objective is to optimize the power captured from the wind, ensure optimum efficiency for power generation and reduce system hardware count. The mathematical model for the permanent magnet synchronous wind turbine and its power control algorithms are modified by removing the speed sensors. Further, enhancement was achieved by utilizing wind speed forecasts as the starting speed. A modified Field Orientation Control FOC and voltage orientation control VOC scheme were developed for the system using matlab Simulink CAD application. The Simulation results of the model for various changes in wind speed utilizing average wind speed data of Mmaku in Awgu local government area of Enugu state Nigeria. The developed system ability to ‘smoothen’ the power, voltage output and operates at the optimum coefficient of performance between the cut in speed of 3m/s and 12m/s without wind sensor is found to be promising, Key words: wind turbine, variable-speed, permanent magnet, synchronous generator, efficiency DOI: 10.7176/JETP/9-3-04 Publication date:March 31st 201

A High-Order Sliding Mode Observer for Sensorless Control ofDFIG-Based Wind Turbines

International audienceThis paper deals with the sensorless control of a doubly-fed induction generator (DFIG) based wind turbine. The sensorless control scheme is based on a high-order sliding mode (HOSM) observer to estimate the DFIG rotational speed. Indeed, high-order sliding mode observers provide theoretically finite time exact state observation and estimation of absolutely continuous unknown inputs. The proposed global control strategy combines an MPPT using a high-order sliding mode speed observer and a high-order sliding mode for the DFIG control. This strategy presents attractive features such as chattering-free behavior, finite reaching time, robustness and unmodeled dynamics (generator and turbine). Simulations using the wind turbine simulator FAST on a 1.5- MW three-blade wind turbine are carried out for the validation of the proposed sensorless control strategy

Feasibility of a Simple Small Wind Turbine with Variable-Speed Regulation Made of Commercial Components

The aim of this study was to propose and evaluate a very small wind turbine (VSWT) that competes with commercial grid-connected VSWTs in terms of simplicity, robustness and price. Its main components are a squirrel-cage induction generator (SCIG) driven by a frequency converter. The system has a direct-drive shaft, and may be constructed with commercial equipment. Simulation of the wind turbine effect is done with a motor. A control program regulates the variable-speed of rotation through three operational modes: (i) to drive the turbine to its optimum operation point; (ii) to limit its maximum rotational speed; and (iii) to limit the maximum power it generates. Two tests were performed, in order to evaluate the dynamic response of this system under variable wind speeds. The tests demonstrate that the system operates at the optimum operational point of the turbine, and within the set limits of maximum rotational speed and maximum generated power. The drop in performance in relation to its nominal value is about 75%, when operating at 50% of the nominal power. In summary, this VSWT with its proposed control program is feasible and reliable for operating direct-shaft grid-connected VSWTs

Low power wind energy conversion system based on variable speed permanent magnet synchronous generators

This paper presents a low power wind energy conversion system (WECS) based on a permanent magnet synchronous generator and a high power factor (PF) rectifier. To achieve a high PF at the generator side, a power processing scheme based on a diode rectifier and a boost DC-DC converter working in discontinuous conduction mode is proposed. The proposed generator control structure is based on three cascaded control loops that regulate the generator current, the turbine speed and the amount of power that is extracted from the wind, respectively, following the turbine aerodynamics and the actual wind speed. The analysis and design of both the current and the speed loops have been carried out taking into consideration the electrical and mechanical characteristics of the WECS, as well as the turbine aerodynamics. The power loop is not a linear one, but a maximum power point tracking algorithm, based on the Perturb and Observe technique, from which is obtained the reference signal for the speed loop. Finally, to avoid the need of mechanical sensors, a linear Kalman Filter has been chosen to estimate the generator speed. Simulation and experimental results on a 2-kW prototype are shown to validate the concept. © 2013 John Wiley & Sons, Ltd.Carranza Castillo, O.; Garcerá Sanfeliú, G.; Figueres Amorós, E.; González Morales, LG. (2014). Low power wind energy conversion system based on variable speed permanent magnet synchronous generators. Wind Energy. 17(6):811-827. doi:10.1002/we.1598S811827176Ackermann, T. (Ed.). (2005). Wind Power in Power Systems. doi:10.1002/0470012684Muyeen, S. M., Shishido, S., Ali, M. H., Takahashi, R., Murata, T., & Tamura, J. (2008). Application of energy capacitor system to wind power generation. Wind Energy, 11(4), 335-350. doi:10.1002/we.265Ladenburg, J. (2009). Stated public preferences for on-land and offshore wind power generation-a review. Wind Energy, 12(2), 171-181. doi:10.1002/we.308Maeda, T., & Kamada, Y. (2009). A review of wind energy activities in Japan. Wind Energy, 12(7), 621-639. doi:10.1002/we.313Baroudi, J. A., Dinavahi, V., & Knight, A. M. (2007). A review of power converter topologies for wind generators. Renewable Energy, 32(14), 2369-2385. doi:10.1016/j.renene.2006.12.002Di Gerlando, A., Foglia, G., Iacchetti, M. F., & Perini, R. (2012). Analysis and Test of Diode Rectifier Solutions in Grid-Connected Wind Energy Conversion Systems Employing Modular Permanent-Magnet Synchronous Generators. IEEE Transactions on Industrial Electronics, 59(5), 2135-2146. doi:10.1109/tie.2011.2157295Yungtaek Jang, & Jovanovic, M. M. (2000). A new input-voltage feedforward harmonic-injection technique with nonlinear gain control for single-switch, three-phase, DCM boost rectifiers. IEEE Transactions on Power Electronics, 15(2), 268-277. doi:10.1109/63.838099Athab, H. S., Lu, D. D.-C., & Ramar, K. (2012). A Single-Switch AC/DC Flyback Converter Using a CCM/DCM Quasi-Active Power Factor Correction Front-End. IEEE Transactions on Industrial Electronics, 59(3), 1517-1526. doi:10.1109/tie.2011.2158771Barbosa, P., Canales, F., Crebier, J.-C., & Lee, F. C. (2001). Interleaved three-phase boost rectifiers operated in the discontinuous conduction mode: analysis, design considerations and experimentation. IEEE Transactions on Power Electronics, 16(5), 724-734. doi:10.1109/63.949505Yao, K., Ruan, X., Mao, X., & Ye, Z. (2011). Variable-Duty-Cycle Control to Achieve High Input Power Factor for DCM Boost PFC Converter. IEEE Transactions on Industrial Electronics, 58(5), 1856-1865. doi:10.1109/tie.2010.2052538Andriollo, M., De Bortoli, M., Martinelli, G., Morini, A., & Tortella, A. (2009). Control strategy of a wind turbine drive by an integrated model. Wind Energy, 12(1), 33-49. doi:10.1002/we.281Hansen, A. D., & Michalke, G. (2008). Modelling and control of variable-speed multi-pole permanent magnet synchronous generator wind turbine. Wind Energy, 11(5), 537-554. doi:10.1002/we.278Salvatore, N., Caponio, A., Neri, F., Stasi, S., & Cascella, G. L. (2010). Optimization of Delayed-State Kalman-Filter-Based Algorithm via Differential Evolution for Sensorless Control of Induction Motors. IEEE Transactions on Industrial Electronics, 57(1), 385-394. doi:10.1109/tie.2009.2033489Kazmi, S. M. R., Goto, H., Guo, H.-J., & Ichinokura, O. (2011). A Novel Algorithm for Fast and Efficient Speed-Sensorless Maximum Power Point Tracking in Wind Energy Conversion Systems. IEEE Transactions on Industrial Electronics, 58(1), 29-36. doi:10.1109/tie.2010.2044732Pucci, M., & Cirrincione, M. (2011). Neural MPPT Control of Wind Generators With Induction Machines Without Speed Sensors. IEEE Transactions on Industrial Electronics, 58(1), 37-47. doi:10.1109/tie.2010.2043043Ming Y Li G Ming Z Chengyong Z Modeling of the wind turbine with a permanent magnet synchronous generator for integration IEEE Power Engineering Society General Meeting, 2007 2007 1 6Carranza O Figueres E Garcera G Gonzalez LG Gonzalez-Espin F Peak current mode control of a boost rectifier with low distortion of the input current for wind power systems based on permanent magnet synchronous generators 13th European Conference on Power Electronics and Applications, EPE ’09 2009 1 10Eltamaly, A. M. (2007). Harmonics reduction of three-phase boost rectifier by modulating duty ratio. Electric Power Systems Research, 77(10), 1425-1431. doi:10.1016/j.epsr.2006.10.012Vorperian, V. (1990). Simplified analysis of PWM converters using model of PWM switch. Continuous conduction mode. IEEE Transactions on Aerospace and Electronic Systems, 26(3), 490-496. doi:10.1109/7.106126Ridley, R. B. (1991). A new, continuous-time model for current-mode control (power convertors). IEEE Transactions on Power Electronics, 6(2), 271-280. doi:10.1109/63.76813Carranza O Figueres E Garcera G Trujillo CL Velasco D Comparison of speed estimators applied to wind generation systems with noisy measurement signals ISIE 2010 IEEE International Symposium on Industrial 2010 3317 3322Yaoqin J Zhongqing Y Binggang C A new maximum power point tracking control scheme for wind generation International Conference on Power System Technology, PowerCon 2002 IEEE-PES/CSEE 2002 144 148PSIM 7.0 User's Guide (2006), Powersim Inc. 2006Carranza, O., Garcerá, G., Figueres, E., & González, L. G. (2010). Peak current mode control of three-phase boost rectifiers in discontinuous conduction mode for small wind power generators. Applied Energy, 87(8), 2728-2736. doi:10.1016/j.apenergy.2010.02.01