Search results for "wind power"
showing 10 items of 178 documents
Parametric Models for Predicting the Performance of Wind Turbines
2020
Abstract Performances of eight parametric power curve models for wind turbines, which can be used for the planning and management of wind energy projects, are compared in this study. Initially, the manufacturer’s power curves of four wind turbines are compared with their field performances. Then, the parametric models are developed for these turbines which are tested with their site performances. Out of the models, WERA showed the best performance in case of all the turbines. Finally, a method for using WERA in extrapolating the performance of turbines with limited test data is demonstrated with the case of a 1 kW turbine.
Integrated GNSS/IMU Hub Motion Estimator for Offshore Wind Turbine Blade Installation
2019
Abstract Offshore wind turbines (OWTs) have become increasingly popular for their ability to harvest clean offshore wind energy. Bottom-fixed foundations are the most used foundation type. Because of its large diameter, the foundation is sensitive to wave loads. For typical manually assisted blade-mating operations, the decision to perform the mating operation is based on the relative distance and velocity between the blade root center and the hub, and in accordance with the weather window. Hence, monitoring the hub real-time position and velocity is necessary, whether the blade installation is conducted manually or automatically. In this study, we design a hub motion estimation algorithm f…
A review of diagnostics and prognostics of low-speed machinery towards wind turbine farm-level health management
2016
Abstract Large wind farms are gaining prominence due to increasing dependence on renewable energy. In order to operate these wind farms reliably and efficiently, advanced maintenance strategies such as condition based maintenance are necessary. However, wind turbines pose unique challenges in terms of irregular load patterns, intermittent operation and harsh weather conditions, which have deterring effects on life of rotating machinery. This paper reviews the state-of-the-art in the area of diagnostics and prognostics pertaining to two critical failure prone components of wind turbines, namely, low-speed bearings and planetary gearboxes. The survey evaluates those methods that are applicabl…
Direct Torque Control of a Small Wind Turbine with a Sliding-Mode Speed Controller
2016
In this paper. the method of direct torque control in the presence of a sliding-mode speed controller is proposed for a small wind turbine being used in water heating applications. This concept and control system design can be expanded to grid connected or off-grid applications. Direct torque control of electrical machines has shown several advantages including very fast dynamics torque control over field-oriented control. Moreover. the torque and flux controllers in the direct torque control algorithms are based on hvsteretic controllers which are nonlinear. In the presence of a sliding-mode speed control. a nonlinear control system can be constructed which is matched for AC/DC conversion …
Inverse kinematic control of an industrial robot used in Vessel-to-Vessel Motion Compensation
2017
An increased level of complex offshore load handling operations is expected due to an increased amount of floating wind turbines, remote fish farms, and autonomous shipping, and in general more advanced operations to be carried out at sea. A common problem for these applications is that both equipment and personnel have to be transported between two floating vessels at sea. An investigation of the Vessel-to-Vessel Motion Compensation (VVMC) problem may increase the efficiency and safety of such operations in the future. In this paper, a control algorithm has been developed and experimentally tested in the Norwegian Motion Laboratory featuring two Stewart platforms (SPs), an industrial robot…
A predictive learning approach to optimal load sharing in energy management systems
2019
Given the total power demand, $P_{d}$ , current practice of equal load sharing in the process industry is to distribute the load among power supply units and machines (e.g., diesel/aas/wind turbines) in proportion to the maximum power, i.e., $P_{i}=\frac{p_{\max}^{i}}{\sum_{j}P_{\max}^{j}}P_{d}$ , where $P_{\max}^{i}$ denotes the maximum power of the ithunit. However, the efficiency of power supply units, vary in time and are highly individual, even in the case of units from same brand and model. Thus, by considering and utilizing these individual differences, it is possible to share the load in a more fuel/cost/energy optimal manner. To capture this potential, the work presented in this pa…
Design of a telescopic tower for wind energy production with reduced environmental impact
2019
A prototype of a telescopic pole for wind energy production with low environmental impact and its lifting system for a 60 to 250 kW turbine and a height of 30 m have been designed and manufactured. A telescopic tower, which is raised and lowered by automation or by remote control, allows to differentiate the presence of the generator within the landscape over time. The technology currently available for lifting and lowering wind turbines is made up of telescopic poles of heights of less than 10 meters and with tilting posts of height below 30 m. Without a state of the art to refer to, the telescopic pole and its lifting system have been designed starting from scratch and solving with innova…
Damage identification of a jacket support structure for offshore wind turbines
2020
Offshore jacket structures are regarded as a suitable type of support structure for offshore wind turbines in immediate water depths. Because of the welded tubular members used and environmental conditions, offshore jackets are often subjected to fatigue damages during their service life. Underwater sensors can provide measurements of the structural vibration signals and provide an efficient way to detect damages at early stages. In this work, simplified forms of the damages are assumed, random damages are imposed on the jacket structure, and damaged indicators are established from combination of modal shapes. Then, a response surface is constructed mapping the damage indicators and damages…
Dynamic mean absolute error as new measure for assessing forecasting errors
2018
Abstract Accurate wind power forecast is essential for grid integration, system planning, and electricity trading in certain electricity markets. Therefore, analyzing prediction errors is a critical task that allows a comparison of prediction models and the selection of the most suitable model. In this work, the temporal error and absolute magnitude error are simultaneously considered to assess the forecast error. The trade-off between both types of errors is computed, analyzed, and interpreted. Moreover, a new index, the dynamic mean absolute error, DMAE, is defined to measure the prediction accuracy. This index accounts for both error components: temporal and absolute. Real cases of wind …
Modelling and analysis of real-world wind turbine power curves: Assessing deviations from nominal curve by neural networks
2019
Abstract The power curve of a wind turbine describes the generated power versus instantaneous wind speed. Assessing wind turbine performance under laboratory ideal conditions will always tend to be optimistic and rarely reflects how the turbine actually behaves in a real situation. Occasionally, some aerogenerators produce significantly different from nominal power curve, causing economic losses to the promoters of the investment. Our research aims to model actual wind turbine power curve and its variation from nominal power curve. The study was carried out in three different phases starting from wind speed and related power production data of a Senvion MM92 aero-generator with a rated powe…