scholarly journals Holistic simulation of wind turbines with fully aero-elastic and electrical model

Author(s):  
Marcus Wiens ◽  
Sebastian Frahm ◽  
Philipp Thomas ◽  
Shoaib Kahn

AbstractRequirements for the design of wind turbines advance facing the challenges of a high content of renewable energy sources in the public grid. A high percentage of renewable energy weaken the grid and grid faults become more likely, which add additional loads on the wind turbine. Load calculations with aero-elastic models are standard for the design of wind turbines. Components of the electric system are usually roughly modeled in aero-elastic models and therefore the effect of detailed electrical models on the load calculations is unclear. A holistic wind turbine model is obtained, by combining an aero-elastic model and detailed electrical model into one co-simulation. The holistic model, representing a DFIG turbine is compared to a standard aero-elastic model for load calculations. It is shown that a detailed modelling of the electrical components e.g., generator, converter, and grid, have an influence on the results of load calculations. An analysis of low-voltage-ride-trough events during turbulent wind shows massive increase of loads on the drive train and effects the tower loads. Furthermore, the presented holistic model could be used to investigate different control approaches on the wind turbine dynamics and loads. This approach is applicable to the modelling of a holistic wind park to investigate interaction on the electrical level and simultaneously evaluate the loads on the wind turbine.

2015 ◽  
Vol 787 ◽  
pp. 217-221 ◽  
Author(s):  
B. Navin Kumar ◽  
K.M. Parammasivam

Wind energy is one of the most significant renewable energy sources in the world. It is the only promising renewable energy resource that only can satisfy the nation’s energy requirements over the growing demand for electricity. Wind turbines have been installed all over the wind potential areas to generate electricity. The wind turbines are designed to operate at a rated wind velocity. When the wind turbines are exposed to extreme wind velocities such as storm or hurricane, the wind turbine rotates at a higher speed that affects the structural stability of the entire system and may topple the system. Mechanical braking systems and Aerodynamic braking systems have been currently used to control the over speeding of the wind turbine at extreme wind velocity. As a novel approach, it is attempted to control the over speeding of the wind turbine by aerodynamic braking system by providing the chord wise spacing (opening). The turbine blade with chord wise spacing alters the pressure distribution over the turbine blade that brings down the rotational speed of the wind turbine within the allowable limit. In this approach, the over speeding of the wind turbine blades are effectively controlled without affecting the power production. In this paper the different parameters of the chord wise spacing such as position of the spacing, shape of the spacing, width of the spacing and impact on power generation are analyzed and the spacing parameters are experimentally optimized.


Author(s):  
Kishor Sontakke ◽  
Samir Deshmukh ◽  
Sandip Patil

The growing demand for electrical energy for industrial and domestic use, coupled with the limited amount of available fossil fuel reserves and its negative effects on the environment, have made it necessary to seek alternative and renewable energy sources. The use of renewable energy is promoted worldwide to be less dependent on conventional fuels and nuclear energy. Therefore research in the field is motivated to increase efficiency of renewable energy systems. This study aimed to study potential of micro wind turbine and velocity profile through shroud for low wind speeds. Although there is a greater inclination to use solar panels because of the local weather conditions, there are some practical implications that have place the use of solar panels in certain areas to an end. The biggest problem is panel stealing. Also, in some parts of the country the weather is more appropriate to apply wind turbines. Thus, this study paying attention on the design of a new concept to improve wind turbines to be appropriate for the low wind speeds in India. The concept involves the implementation of a concentrator and diffuser to a wind turbine, to increase the power coefficient. Although the wind turbine was not tested for starting speeds, the realization of the shroud should contribute to improved starting of the wind turbine at lower wind speeds. The configuration were not manufactured, but simulated with the use of a program to obtain the power production of the wind turbine over a range of wind speeds. These values were compared to measured results of an open wind turbine developed. The most important topic at hand when dealing with a shrouded wind turbine is to find out if the overall diameter or the blade diameter of the turbine should be the point of reference. As the wind turbine is situated in a shroud that has a larger diameter than the turbine blades, some researchers believe that the overall diameter should be used to calculate the efficiency. The benefits of shrouded wind turbines are discussed.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2151
Author(s):  
Feras Alasali ◽  
Husam Foudeh ◽  
Esraa Mousa Ali ◽  
Khaled Nusair ◽  
William Holderbaum

More and more households are using renewable energy sources, and this will continue as the world moves towards a clean energy future and new patterns in demands for electricity. This creates significant novel challenges for Distribution Network Operators (DNOs) such as volatile net demand behavior and predicting Low Voltage (LV) demand. There is a lack of understanding of modern LV networks’ demand and renewable energy sources behavior. This article starts with an investigation into the unique characteristics of householder demand behavior in Jordan, connected to Photovoltaics (PV) systems. Previous studies have focused mostly on forecasting LV level demand without considering renewable energy sources, disaggregation demand and the weather conditions at the LV level. In this study, we provide detailed LV demand analysis and a variety of forecasting methods in terms of a probabilistic, new optimization learning algorithm called the Golden Ratio Optimization Method (GROM) for an Artificial Neural Network (ANN) model for rolling and point forecasting. Short-term forecasting models have been designed and developed to generate future scenarios for different disaggregation demand levels from households, small cities, net demands and PV system output. The results show that the volatile behavior of LV networks connected to the PV system creates substantial forecasting challenges. The mean absolute percentage error (MAPE) for the ANN-GROM model improved by 41.2% for household demand forecast compared to the traditional ANN model.


2021 ◽  
Vol 13 (19) ◽  
pp. 11059
Author(s):  
Shahrukh Khan ◽  
Arshad Mahmood ◽  
Mohammad Zaid ◽  
Mohd Tariq ◽  
Chang-Hua Lin ◽  
...  

High gain DC-DC converters are getting popular due to the increased use of renewable energy sources (RESs). Common ground between the input and output, low voltage stress across power switches and high voltage gain at lower duty ratios are desirable features required in any high gain DC-DC converter. DC-DC converters are widely used in DC microgrids to supply power to meet local demands. In this work, a high step-up DC-DC converter is proposed based on the voltage lift (VL) technique using a single power switch. The proposed converter has a voltage gain greater than a traditional boost converter (TBC) and Traditional quadratic boost converter (TQBC). The effect of inductor parasitic resistances on the voltage gain of the converter is discussed. The losses occurring in various components are calculated using PLECS software. To confirm the performance of the converter, a hardware prototype of 200 W is developed in the laboratory. The simulation and hardware results are presented to determine the performance of the converter in both open-loop and closed-loop conditions. In closed-loop operation, a PI controller is used to maintain a constant output voltage when the load or input voltage is changed.


2021 ◽  
Vol 9 (1) ◽  
pp. 96-103
Author(s):  
Ruba Asim Hamza ◽  
Amged Osman Abdelatif

Sudan is one of the developing countries that suffers from a lack of electricity, where the national electrification rate is estimated at 38.5%. In order to solve this problem, it is possible to use renewable energy sources such as wind energy. Beside many aspects to be considered at the design of wind turbine foundations, more attention should be given to the geotechnical part. There are many types of foundations for wind turbines. The foundation must satisfy two design criteria: 1) It should be safe against bearing failure in soils under design loads and settlements during the life of the structure must not cause structural damage; 2) In addition to static loads, wind turbine foundations loads are extremely eccentrically and the loading is usually highly dynamic. Therefore, the selection of foundation type should consider these two criteria taking into account the nature and magnitude of these loads. This paper presents a review of different types of wind turbine foundations of focusing on on-shore wind turbine foundation types and the dynamic response of wind turbine. The paper also demonstrate experimentally the dynamic response of the wind turbines using wind tunnel facility test on a scaled model.  


Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 805
Author(s):  
Lida Liao ◽  
Bin Huang ◽  
Qi Tan ◽  
Kan Huang ◽  
Mei Ma ◽  
...  

Given the prejudicial environmental effects of fossil-fuel based energy production, renewable energy sources can contribute significantly to the sustainability of human society. As a clean, cost effective and inexhaustible renewable energy source, wind energy harvesting has found a wide application to replace conventional energy productions. However, concerns have been raised over the noise generated by turbine operating, which is helpful in fault diagnose but primarily identified for its adverse effects on the local ecosystems. Therefore, noise monitoring and separation is essential in wind turbine deployment. Recent developments in condition monitoring provide a solution for turbine noise and vibration analysis. However, the major component, aerodynamic noise is often distorted in modulation, which consequently affects the condition monitoring. This study is conducted to explore a novel approach to extract low-frequency elements from the aerodynamic noise background, and to improve the efficiency of online monitoring. A framework built on the spline envelope method and improved local mean decomposition has been developed for low-frequency noise extraction, and a case study with real near-field noises generated by a mountain-located wind turbine was employed to validate the proposed approach. Results indicate successful extractions with high resolution and efficiency. Findings of this research are also expected to further support the fault diagnosis and the improvement in condition monitoring of turbine systems.


Sci ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 43 ◽  
Author(s):  
Patrick Moriarty ◽  
Damon Honnery

Because of the near-term risk of extreme weather events and other adverse consequences from climate change, and, at least in the longer term, global fossil fuel depletion, there is world-wide interest in shifting to noncarbon energy sources, especially renewable energy (RE). Because of possible limitations on conventional renewable energy sources, researchers have looked for ways of overcoming these shortcomings by introducing radically new energy technologies. The largest RE source today is bioenergy, while solar energy and wind energy are regarded as having the largest technical potential. This paper reviews the literature on proposed new technologies for each of these three RE sources: microalgae for bioenergy, photolysis and airborne wind turbines. The main finding is that their proponents have underestimated the difficulties facing their introduction on a very large scale.


Author(s):  
R. S. Amano ◽  
Ryan J. Malloy

Recently there has been an increase in the demand for the utilization of clean renewable energy sources. This is a direct result of a rise in oil prices and an increased awareness of human induced climate change. Wind energy has been shown to be one of the most promising sources of renewable energy. With current technology, the low cost of wind energy is competitive with more conventional sources of energy such as coal. This however is only true in areas of high wind density. These areas are not as abundant and therefore the number of profitable sites is limited. This paper explores the possibility increasing the number of profitable sites by optimizing wind turbine blade design for low wind speed areas. The two methods of optimization that are investigated are first, optimizing the angle of attack and chord length for a given airfoil cross section at different positions along the blade and second implementing a swept blade profile. The torque generated from a blade using only the first optimization technique is compared to that generated from a blade using both techniques as well as that generated by NTK500/41 turbine using LM19.1 blades. Performance will be investigated using the CFD solver FLUENT.


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