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14 pages, 8265 KiB

Open AccessArticle

Power Flow Analysis on the Dual Input Transmission Mechanism of Small Wind Turbine Systems

by Ah-Der Lin, Tsung-Pin Hung, Jao-Hwa Kuang and Hsiu-An Tsai

Appl. Sci. 2020, 10(20), 7333; https://doi.org/10.3390/app10207333 - 20 Oct 2020

Cited by 7 | Viewed by 1890

Abstract

A parallel planetary gear train design is proposed to construct the wind turbine system that has double inputs and one output. The proposed system is flexible for the application, which may use a combination of two rotors, as used for horizontal axis or [...] Read more.

A parallel planetary gear train design is proposed to construct the wind turbine system that has double inputs and one output. The proposed system is flexible for the application, which may use a combination of two rotors, as used for horizontal axis or vertical axis wind turbines. The proposed transmission mechanism merges the dual time varied input wind powers to a synchronous generator. The effect of the gear train parameters on the dynamic power flow variation is modeled and simulated for the proposed wind turbine system. Results indicate the proposed planetary gear train system is a feasible and efficient design for its application to wind turbine systems. The dynamic torque equilibrium equations between meshed gear pairs are employed to analyze the dynamic power flow. The nonlinear behavior of a synchronous generator is also included in the modeling. The dynamic responses of the dual input transmission mechanism are simulated using the 4th order Runge–Kutta method. The study also investigates the effect of system parameters used in this wind turbine system (i.e., the wind speed, the magnetic flux synchronous generator, and the inertia of flywheels) on variations in electrical power output. Full article

(This article belongs to the Special Issue Wind Power Systems: Design, Operation, and Control)

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20 pages, 9531 KiB

Open AccessArticle

Finite-Time Fast Dynamic Terminal Sliding Mode Maximum Power Point Tracking Control Paradigm for Permanent Magnet Synchronous Generator-Based Wind Energy Conversion System

by Muhammad Zafran, Laiq Khan, Qudrat Khan, Shafaat Ullah, Irfan Sami and Jong-Suk Ro

Appl. Sci. 2020, 10(18), 6361; https://doi.org/10.3390/app10186361 - 12 Sep 2020

Cited by 13 | Viewed by 2392

Abstract

Due to the intermittent nature of wind, there exists a major disparity between the power generation from the wind and the demand of electricity. Hence, a sophisticated maximum power point tracking (MPPT) control paradigm must be formulated for maximizing the power extraction from [...] Read more.

Due to the intermittent nature of wind, there exists a major disparity between the power generation from the wind and the demand of electricity. Hence, a sophisticated maximum power point tracking (MPPT) control paradigm must be formulated for maximizing the power extraction from the wind. This research article focuses on the formulation of a nonlinear fast dynamic terminal sliding mode control (FDTSMC)-based MPPT strategy for optimizing the power extraction from a 3kW, variable speed, fixed-pitch wind energy conversion system equipped with a permanent magnet synchronous generator. The proposed MPPT strategy is compared with the benchmark fast terminal sliding mode control, conventional sliding mode control, feedback linearization control and proportional integral derivative control-based MPPT strategies under a stochastic wind speed profile. The proposed paradigm has been found superior in its tracking performance by converging the output tracking error to zero in a finite time, realizing a high precision performance, offering fast dynamic response, reducing the chattering to a minute level and guaranteeing global robustness. The superior performance and effectiveness of the proposed FDTSMC-based MPPT control paradigm is tested and validated through extensive MATLAB/Simulink simulations. Full article

(This article belongs to the Special Issue Wind Power Systems: Design, Operation, and Control)

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35 pages, 3859 KiB

Open AccessArticle

Stochastic Extreme Wind Speed Modeling and Bayes Estimation under the Inverse Rayleigh Distribution

by Elio Chiodo and Luigi Pio Di Noia

Appl. Sci. 2020, 10(16), 5643; https://doi.org/10.3390/app10165643 - 14 Aug 2020

Cited by 5 | Viewed by 1716

Abstract

Inverse Rayleigh probability distribution is shown in this paper to constitute a valid model for characterization and estimation of extreme values of wind speed, thus constituting a useful tool of wind power production evaluation and mechanical safety of installations. The first part of [...] Read more.

Inverse Rayleigh probability distribution is shown in this paper to constitute a valid model for characterization and estimation of extreme values of wind speed, thus constituting a useful tool of wind power production evaluation and mechanical safety of installations. The first part of this paper illustrates such a model and its validity to interpret real wind speed field data. The inverse Rayleigh model is then adopted as the parent distribution for assessment of a dynamical “risk index” defined in terms of a stochastic Poisson process, based upon crossing a given value with part of the maximum value of wind speed on a certain time horizon. Then, a novel Bayes approach for the estimation of such an index under the above model is proposed. The method is based upon assessment of prior information in a novel way which should be easily feasible for a system engineer, being based upon a model quantile (e.g., the median value) or, alternatively, on the probability that the wind speed is greater than a given value. The results of a large set of numerical simulation—based upon typical values of wind-speed parameters—are reported to illustrate the efficiency and the precision of the proposed method, also with hints to its robustness. The validity of the approach is also verified with respect to the two different methods of assessing the prior information. Full article

(This article belongs to the Special Issue Wind Power Systems: Design, Operation, and Control)

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16 pages, 3147 KiB

Open AccessArticle

Short-Term Wind Speed Prediction Based on Principal Component Analysis and LSTM

by Dawei Geng, Haifeng Zhang and Hongyu Wu

Appl. Sci. 2020, 10(13), 4416; https://doi.org/10.3390/app10134416 - 27 Jun 2020

Cited by 29 | Viewed by 3482

Abstract

An accurate prediction of wind speed is crucial for the economic and resilient operation of power systems with a high penetration level of wind power. Meteorological information such as temperature, humidity, air pressure, and wind level has a significant influence on wind speed, [...] Read more.

An accurate prediction of wind speed is crucial for the economic and resilient operation of power systems with a high penetration level of wind power. Meteorological information such as temperature, humidity, air pressure, and wind level has a significant influence on wind speed, which makes it difficult to predict wind speed accurately. This paper proposes a wind speed prediction method through an effective combination of principal component analysis (PCA) and long short-term memory (LSTM) network. Firstly, PCA is employed to reduce the dimensions of the original multidimensional meteorological data which affect the wind speed. Further, differential evolution (DE) algorithm is presented to optimize the learning rate, number of hidden layer nodes, and batch size of the LSTM network. Finally, the reduced feature data from PCA and the wind speed data are merged together as an input to the LSTM network for wind speed prediction. In order to show the merits of the proposed method, several prevailing prediction methods, such as Gaussian process regression (GPR), support vector regression (SVR), recurrent neural network (RNN), and other forecasting techniques, are introduced for comparative purposes. Numerical results show that the proposed method performs best in prediction accuracy. Full article

(This article belongs to the Special Issue Wind Power Systems: Design, Operation, and Control)

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21 pages, 6497 KiB

Open AccessArticle

Flexible Power System Defense Strategies in an Isolated Microgrid System with High Renewable Power Generation

by Yuan-Kang Wu, Kuo-Ting Tang, Zheng Kuan Lin and Wen-Shan Tan

Appl. Sci. 2020, 10(9), 3184; https://doi.org/10.3390/app10093184 - 2 May 2020

Cited by 5 | Viewed by 1771

Abstract

This work develops an underfrequency preventive control strategy for an islanded power system with a high penetration of wind power generation. First, the preventive control strategy uses the frequency nadir forecasting module to analyze the frequency stability under largest diesel generator tripping ( [...] Read more.

This work develops an underfrequency preventive control strategy for an islanded power system with a high penetration of wind power generation. First, the preventive control strategy uses the frequency nadir forecasting module to analyze the frequency stability under largest diesel generator tripping (N-1) contingency events. If predicted frequency nadir is too low, four frequency support methods are then analyzed and used for preventing potential frequency stability problem. They include generator rescheduling (GR), the use of battery energy storage system (BESS), direct load control (DLC) and emergency demand response program (EDRP). In terms of the GR method, the optimal diesel generator dispatch is obtained, with sufficient frequency stability and minimal fuel cost and start-up cost. In the BESS method, the optimal instantaneous power output from BESS is obtained based on its frequency support capability. With the DLC or EDRP method, the optimal contract-based load-shedding or the load-reduction to provide frequency support is obtained, respectively. Then, the operating costs of each method to support frequency are analyzed. The research methods and simulation results are very useful to the low-frequency protection of actual power systems with high renewable power generation. This work proposed a complete defense strategy in a microgrid system. It combines GR, BESS, DLC and EDRP. Therefore, the system operators have many options to implement their defense strategies, based on the operating costs of various methods. In other words, the proposed defense strategy provides a more flexible solution for the protection of micro grids with a high renewable power penetration. Therefore, the solution considers the system safety and economical aspects. Full article

(This article belongs to the Special Issue Wind Power Systems: Design, Operation, and Control)

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11 pages, 1012 KiB

Open AccessArticle

Improving the Performance of Doubly Fed Induction Generator Using Fault Tolerant Control—A Hierarchical Approach

by Muhammad Shahzad Nazir, Yeqin Wang, Ali Jafer Mahdi, Xinguo Sun, Chu Zhang and Ahmed N. Abdalla

Appl. Sci. 2020, 10(3), 924; https://doi.org/10.3390/app10030924 - 31 Jan 2020

Cited by 21 | Viewed by 2967

Abstract

The growth of using wind energy on a large scale increases the demand for wind energy conversion machines (WECMs), among these converters, the doubly-fed induction generator (DFIG) is the favorite choice. However, DFIG is very sensitive to wind speed variations and grid faults [...] Read more.

The growth of using wind energy on a large scale increases the demand for wind energy conversion machines (WECMs), among these converters, the doubly-fed induction generator (DFIG) is the favorite choice. However, DFIG is very sensitive to wind speed variations and grid faults during operation. In order to overcome these undesirable characteristics, this paper proposes a hierarchical fault tolerant control (FTC) to improve the performance of DFIG. The hierarchical fault tolerant control (FTC) approach consists of pitch angle control (PAC) and maximum power point tracking (MPPT). This hierarchical approach demonstrates the robust response under various (low, rated, and high) wind speed ranges and reduces the undesirable DC voltage overshoots during short-circuit disorder. The simulation results are summarized in a logical table, which depicts the order of controlling scheme and operation for a sustainable energy generation system. The proposed control scheme achieved the healthy and the robust dynamic response without deteriorating the grid power quality or stressing the converters, and approved the effectiveness to suppress the DC voltage overshoots and tolerate the lower down short-circuit disorder to its rated range. Full article

(This article belongs to the Special Issue Wind Power Systems: Design, Operation, and Control)

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19 pages, 2726 KiB

Open AccessArticle

Nonlinear Maximum Power Point Tracking Control Method for Wind Turbines Considering Dynamics

by Liangwen Qi, Liming Zheng, Xingzhi Bai, Qin Chen, Jiyao Chen and Yan Chen

Appl. Sci. 2020, 10(3), 811; https://doi.org/10.3390/app10030811 - 23 Jan 2020

Cited by 13 | Viewed by 2267

Abstract

A combined strategy of torque error feed-forward control and blade-pitch angle servo control is proposed to improve the dynamic power capture for wind turbine maximum power point tracking (MPPT). Aerodynamic torque is estimated using the unscented Kalman filter (UKF). Wind speed and tip [...] Read more.

A combined strategy of torque error feed-forward control and blade-pitch angle servo control is proposed to improve the dynamic power capture for wind turbine maximum power point tracking (MPPT). Aerodynamic torque is estimated using the unscented Kalman filter (UKF). Wind speed and tip speed ratio (TSR) are estimated using the Newton–Raphson method. The error between the estimated aerodynamic torque and the steady optimal torque is used as the feed-forward signal to control the generator torque. The gain parameters in the feed-forward path are nonlinearly regulated by the estimated generator speed. The estimated TSR is used as the reference signal for the optimal blade-pitch angle regulation at non-optimal TSR working points, which can improve the wind power capture for a wider non-optimal TSR range. The Fatigue, Aerodynamics, Structures, and Turbulence (FAST) code is used to simulate the aerodynamics and mechanical aspects of wind turbines while MATLAB/SIMULINK is used to simulate the doubly-fed induction generator (DFIG) system. The example of a 5 MW wind turbine model reveals that the new method is able to improve the dynamic response of wind turbine MPPT and wind power capture. Full article

(This article belongs to the Special Issue Wind Power Systems: Design, Operation, and Control)

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Graphical abstract

14 pages, 2433 KiB

Open AccessArticle

A Flutter-Based Electromagnetic Wind Energy Harvester: Theory and Experiments

by Zhuang Lu, Quan Wen, Xianming He and Zhiyu Wen

Appl. Sci. 2019, 9(22), 4823; https://doi.org/10.3390/app9224823 - 11 Nov 2019

Cited by 18 | Viewed by 3658

Abstract

Wind energy harvesting is a promising way to offer power supply to low-power electronic devices. Miniature wind-induced vibration energy harvesters, which are currently being focused on by researchers in the field, offer the advantages of small volume and simple structure. In this article, [...] Read more.

Wind energy harvesting is a promising way to offer power supply to low-power electronic devices. Miniature wind-induced vibration energy harvesters, which are currently being focused on by researchers in the field, offer the advantages of small volume and simple structure. In this article, an analytical model was proposed for the kinetic analysis of a flutter-based electromagnetic wind energy harvester. As a result, the critical wind speeds of energy harvesters with different magnet positions were predicted. To experimentally verify the analytical predictions and investigate the output performance of the proposed energy harvester, a small wind tunnel was built. The critical wind speeds measured by the experiment were found to be consistent with the predictions. Therefore, the proposed model can be used to predict the critical wind speed of a wind belt type energy harvester. The experimental results also show that placing the magnets near the middle of the membrane can result in lower critical wind speed and higher output performance. The optimized wind energy harvester was found to generate maximum average power of 705 μW at a wind speed of 10 m/s, offering application prospects for the power supply of low-power electronic devices. This work can serve as a reference for the structural design and theoretical analysis of a flutter-based wind energy harvester. Full article

(This article belongs to the Special Issue Wind Power Systems: Design, Operation, and Control)

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Review

Jump to: Research

25 pages, 5429 KiB

Open AccessReview

Low-Voltage Ride-Through Techniques in DFIG-Based Wind Turbines: A Review

by Boyu Qin, Hengyi Li, Xingyue Zhou, Jing Li and Wansong Liu

Appl. Sci. 2020, 10(6), 2154; https://doi.org/10.3390/app10062154 - 22 Mar 2020

Cited by 53 | Viewed by 5230

Abstract

In recent years, considerable advances were made in wind power generation. The growing penetration of wind power makes it necessary for wind turbines to maintain continuous operation during voltage dips, which is stated as the low-voltage ride-through (LVRT) capability. Doubly fed induction generator [...] Read more.

In recent years, considerable advances were made in wind power generation. The growing penetration of wind power makes it necessary for wind turbines to maintain continuous operation during voltage dips, which is stated as the low-voltage ride-through (LVRT) capability. Doubly fed induction generator (DFIG)-based wind turbines (DFIG-WTs), which are widely used in wind power generation, are sensitive to disturbances from the power grid. Therefore, several kinds of protection circuits and control methods are applied to DFIG-WTs for LVRT capability enhancement. This paper gives a comprehensive review and evaluation of the proposed LVRT solutions used in DFIG-WTs, including external retrofit methods and internal control techniques. In addition, future trends of LVRT solutions are also discussed in this paper. Full article

(This article belongs to the Special Issue Wind Power Systems: Design, Operation, and Control)

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