Showing 13 results for Wind Turbine
R. Ghazi, A. Khajeh,
Volume 9, Issue 3 (9-2013)
Abstract
Nowadays, the doubly-fed induction generators (DFIGs) based wind turbines (WTs) are the dominant type of WTs connected to grid. Traditionally the back-to-back converters are used to control the DFIGs. In this paper, an Indirect Matrix Converter (IMC) is proposed to control the generator. Compared with back-to-back converters, IMCs have numerous advantages such as: higher level of robustness, reliability, reduced size and weight due to the absence of bulky electrolytic capacitor. According to the recent grid codes it is required that wind turbines remain connected to the grid during grid faults and following voltage dips. This feature is called low voltage ride-through (LVRT) capability. In this paper the linear quadratic regulator (LQR) controller is used for optimal control of the DFIG. The weighting matrices of the LQR are obtained using the genetic algorithm (GA) technique. With the LQR controller the intention is to improve the LVRT capability of the DFIG wind turbines to satisfy the new LVRT requirements. Compared to the PI controller, the superiority of the LQR controller in improving the transient stability and LVRT performance of the DFIG wind turbines is evident. Simulation results confirm the efficiency of the proposed controller.
H. A. Lari, A. Kiyoumarsi, A. Darijani, B. Mirzaeian Dehkordi, S. M. Madani,
Volume 10, Issue 4 (12-2014)
Abstract
In Permanent-Magnet Synchronous Generators (PMSGs) the reduction of cogging torque is one of the most important problems in their performance and evaluation. In this paper, at first, a direct-drive vertical-axis wind turbine is chosen. According to its nominal value operational point, necessary parameters for the generator is extracted. Due to an analytical method, four generators with different pole-slot combinations are designed. Average torque, torque ripple and cogging torque are evaluated based on finite element method. The combination with best performance is chosen and with the analysis of variation of effective parameters on cogging torque, and introducing a useful method, an improved design of the PMSG with lowest cogging torque and maximum average torque is obtained. The results show a proper performance and a correctness of the proposed method.
M. Hosseinabadi, H. Rastegar,
Volume 10, Issue 4 (12-2014)
Abstract
This paper is concerned with behavior analysis and improvement of wind turbines with Doubly Fed Induction Generator (DFIG) when using a new fractional-order control strategy during wind variations. A doubly fed induction generator, two types of variable frequency power electronic converters and two input wind waveforms are considered. A fractional-order control strategy is proposed for the wind turbine control unit. Output parameters of the wind turbine are drawn by simulations using MATLAB/Simulink for both fractional-order and integer-order (classic) control systems and a complete comparison between these two strategies has been presented. Results show a better operation when using fractional-order control system.
M. Alizadeh Moghadam, R. Noroozian, S. Jalilzadeh,
Volume 11, Issue 3 (9-2015)
Abstract
This paper presents modeling, simulation and control of matrix converter (MC) for variable speed wind turbine (VSWT) system including permanent magnet synchronous generator (PMSG). At a given wind velocity, the power available from a wind turbine is a function of its shaft speed. In order to track maximum power, the MC adjusts the PMSG shaft speed.The proposed control system allowing independent control maximum power point tracking (MPPT) of generator side and regulate reactive power of grid side for the operation of the VSWT system. The MPPT is implemented by a new control system. This control system is based on control of zero d-axis current (ZDC). The ZDC control can be realized by transfer the three-phase stator current in the stationary reference frame into d-and q-axis components in the synchronous reference frame. Also this paper is presented, a novel control strategy to regulate the reactive power supplied by a variable speed wind energy conversion system. This control strategy is based on voltage oriented control (VOC). The simulation results based on Simulink/Matlab software show that the controllers can extract maximum power and regulate reactive power under varying wind velocities.
M.a Armin, H Rajabi Mashhadi,
Volume 11, Issue 4 (12-2015)
Abstract
Wind energy penetration in power system has been increased very fast and large amount of capitals invested for wind farms all around the world. Meanwhile, in power systems with wind turbine generators (WTGs), the value of Available transfer capability (ATC) is influenced by the probabilistic nature of the wind power. The Mont Carlo Simulation (MCS) is the most common method to model the uncertainty of WTG. However, the MCS method suffers from low convergence rate. To overcome this shortcoming, the proposed technique in this paper uses a new formulation for solving ATC problem analytically. This lowers the computational burden of the ATC computation and hence results in increased convergence rate of the MCS. Using this fast technique to evaluate the ATC, wind generation and load correlation is required to get into modeling. A numerical method is presented to consider load and wind correlation. The proposed method is tested on the modified IEEE 118 bus to analyze the impacts of the WTGs on the ATC. The obtained results show that wind generation capacity and its correlation with system load has significant impacts on the network transfer capability. In other words, ATC probability distribution is sensitive to the wind generation capacity.
A. Ejlali, J. Soleimani, A. Vahedi,
Volume 12, Issue 4 (12-2016)
Abstract
Recently, Transverse Flux Permanent Magnet Generators (TFPMGs) have been proposed as a possible generator in direct drive variable speed wind turbines due to their unique merits. Generally, the quality of output power in these systems is lower than multi stage fixed speed systems, because of removing the gears, so it’s important to design these kinds of generators with low ripple and lowest harmful harmonics and cogging torque that is one of the most important terms in increasing the quality of output power of generator. The objective of this paper is introducing a simple design method and optimization of high power TFPMG applied in vertical axis direct drive wind turbine system by lowest possible amplitude of cogging torque and highest possible power factor, efficiency and power density. In order to extract the output values of generator and sensitivity analysis for design and optimization, 3D-Finite element model, has been used. This method has high accuracy and gives us a better insight of generator performance and presents back EMF, cogging torque, flux density and FFT of this TFPMG. This study can help designers in design approach of such motors.
S. Heshmatian, D. Arab Khaburi, M. Khosravi, A. Kazemi,
Volume 14, Issue 1 (3-2018)
Abstract
Wind energy is one of the most promising renewable energy resources. Due to instantaneous variations of the wind speed, an appropriate Maximum Power Point Tracking (MPPT) method is necessary for maximizing the captured energy from the wind at different speeds. The most commonly used MPPT algorithms are Tip Speed Ratio (TSR), Power Signal Feedback (PSF), Optimal Torque Control (OTC) and Hill Climbing Search (HCS). Each of these algorithms has some advantages and also some major drawbacks. In this paper, a novel hybrid MPPT algorithm is proposed which modifies the conventional methods in a way that eliminates their drawbacks and yields an improved performance. This proposed algorithm is faster in tracking the maximum power point and provides a more accurate response with lower steady state error. Moreover, it presents a great performance under conditions with intensive wind speed variations. The studied Wind Energy Conversion System (WECS) consists of a Permanent Magnet Synchronous Generator (PMSG) connected to the dc link through a Pulse-Width Modulated (PWM) rectifier. The proposed algorithm and the conventional methods are applied to this WECS and their performances are compared using the simulation results. These results approve the satisfactory performance of the proposed algorithm and its notable advantages over the conventional methods.
A. Dameshghi, M. H. Refan,
Volume 14, Issue 4 (12-2018)
Abstract
Wind turbines are very important and strategic instruments in energy markets. Wind power production is unreliable. Wind power is weather dependent and the extreme wind speed changes make difficult to control of grid voltage and reactive power. Based on these reasons, Wind Power Prediction (WPP) is important for real applications. In this paper, a new short-term WPP method based on Support Vector Machine (SVM) is proposed. In contrast to physical approaches based on very complex differential equations, the proposed method is based on data history. Firstly, data preprocessing and normalization is done. Secondly, formulate the prediction as a regression problem. Thirdly, the prediction model is constructed using the Particle Swarm Optimization (PSO) and Least Square Support Vector Machine (LSSVM). In this paper, instead of using the conventional kernels, such as linear kernel, Polynomial and Radial basis function (RBF), the Wavelet (W) transform is used. The PSO-LS-WSVM accuracy has been tested with industrial wind energy data. This method has been compared with other methods and the experimental results based on practical data illustrate that PSO-LS-WSVM proposed method has better responses than other methods. Statistical results indicate that the predicting error of PSO-LS-WSVM is 2.98% for one look-ahead hour.
E. Bounadja, Z. Boudjema, A. Djahbar,
Volume 15, Issue 3 (9-2019)
Abstract
This paper proposes a novel wind energy conversion system based on a Five-phase Permanent Magnetic Synchronous Generator (5-PMSG) and a Five to three Matrix Converter (5-3MC). The low cost and volume and also eliminating grid side converter controller are attractive aspects of the proposed topology compared to the conventional with back-to-back converters. The control of active and reactive power injected to the grid from the proposed system is carried out by a Direct Power Control (DPC) combined with a Space Vector Modulation (SVM). An advantage of this control, compared with the Conventional Direct Power Control (C-DPC) method, is that it eliminates the lookup table and lowers grid powers and currents harmonics through the use of a standard PI controller instead of hysteresis comparators. The efficiency of proposed whole system has been simulated by using MATLAB/Simulink environment.
T. Agheb, I. Ahmadi, A. Zakariazadeh,
Volume 17, Issue 3 (9-2021)
Abstract
Optimal placement and sizing of distributed renewable energy resources (DER) in distribution networks can remarkably influence voltage profile improvement, amending of congestions, increasing the reliability and emission reduction. However, there is a challenge with renewable resources due to the intermittent nature of their output power. This paper presents a new viewpoint at the uncertainties associated with output powers of wind turbines and load demands by considering the correlation between them. In the proposed method, considering the simultaneous occurrence of real load demands and wind generation data, they are clustered by use of the k-means method. At first, the wind generation data are clustered in some levels, and then the associated load data of each generation level are clustered in several levels. The number of load levels in each generation level may differ from each other. By doing so the unrealistic generation-load scenarios are omitted from the process of wind turbine sizing and placement. Then, the optimum sizing and placement of distributed generation units aiming at loss reduction are carried out using the obtained generation-load scenarios. Integer-based Particle Swarm Optimization (IPSO) is used to solve the problem. The simulation result, which is carried out using MATLAB 2016 software, shows that the proposed approach causes to reduce annual energy losses more than the one in other methods. Moreover, the computational burden of the problem is decreased due to ignore some unrealistic scenarios of wind and load combinations.
Vahid Bagheri, Amir Farhad Ehyaei, Mohammad Haeri,
Volume 18, Issue 4 (12-2022)
Abstract
In distribution networks, failure to smooth the load curve leads to voltage drop and power quality loss. In this regard, electric vehicle batteries can be used to smooth the load curve. However, to persuade vehicle owners to share their vehicle batteries, we must also consider the owners' profits. A challenging problem is that existing methods do not take into account the vehicle owner demands including initial and final states of charge and arrival and departure times of vehicles. Another problem is that battery capacity of each vehicle varies depending on the type of vehicle; which leads to uncertainties in the charging and discharging dynamics of batteries. In this paper, we propose a modified mean-field method so that the load curve is smoothed, vehicle owner demands are met, and different capacities of electric vehicle batteries are considered. The simulation results show the effectiveness of the proposed method.
I. K. Okakwu, O. E. Olabode, D. O. Akinyele, T. O. Ajewole,
Volume 19, Issue 2 (6-2023)
Abstract
This paper evaluates the wind potential of some specified locations in Nigeria, and then examines the response of wind energy conversion systems (WECSs) to this potential. The study employs eight probability distribution (PD) functions such as Weibull (Wbl), Rayleigh (Ryh), Lognormal (Lgl), Gamma (Gma), Inverse Gaussian (IG), Normal (Nl), Maxwell (Mwl) and Gumbel (Gbl) distributions to fit the wind data for nine locations in Nigeria viz. Kano, Maiduguri, Jos, Abuja, Akure, Abeokuta, Uyo, Warri and Ikeja. The paper then uses the maximum likelihood (ML) method to obtain the parameters of the distributions and then evaluates the goodness of fit for the PD models to characterize the locations’ wind speeds using the minimum Root Mean Square Error (RMSE). The paper analyses the techno-economic aspect of the WECSs based on the daily average wind speed; it evaluates the performance of ten 25 kW pitch-controlled wind turbines (WT1 – WT10) with dissimilar characteristics for each location, including the cost/kWh of energy (COE) and the sensitivity analyses of the WECSs. Results reveal that Ryh distribution shows the best fit for Kano, Jos, Abeokuta, Uyo, Warri and Ikeja, while the Lgl distribution shows the best fit for Maiduguri, Abuja and Akure due to their minimum RMSE. WT7 achieves the least COE ranging from $0.0328 in Jos to $4.4922 in Uyo and WT5 has the highest COE ranging from $0.1380 in Ikeja to $53.371 in Uyo. The paper also details the sensitivity analysis for the technical and economic aspects.
G. Hamza, M. Sofiane, H. Benbouhenni, N. Bizon,
Volume 19, Issue 2 (6-2023)
Abstract
In this paper, a wind power system based on a doubly-fed induction generator (DFIG) is modeled and simulated. To guarantee high-performance control of the powers injected into the grid by the wind turbine, five intelligent super-twisting sliding mode controllers (STSMC) are used to eliminate the active power and current ripples of the DFIG. The STSMC controller is a high-order sliding mode controller which offers high robustness compared to the traditional sliding mode controller. In addition, it reduces the phenomenon of chattering due to the discontinuous component of the SMC technique. However, the simplicity, ease of execution, durability, and ease of adjusting response are among the most important features of this control compared to some other types. To increase the robustness and improve the response of STSMC, particle swarm optimization method is used for this purpose, where this algorithm is used for parameter calculation. The simulation results obtained using MATLAB software confirm the characteristics of the designed strategy in reducing chattering and ensuring good power control of the DFIG-based wind power.
