Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Wind Turbine Control Via Power Measurements in Complex Terrain(01. Izmir Institute of Technology, 2022) Dirik, Deniz Gökhan; Bingöl, FerhatThis work presents an approach to the assessment of wind farm yaw control to utilize wake steering in complex terrain based on power measurements. Aerodynamic interactions between closely spaced wind turbines reduce the power output significantly. The standard wind turbine control strategy currently focuses on optimizing the wind turbines individually. However, there is growing evidence that these wake losses can be improved by optimizing for aerodynamic interactions between the turbines. In a case study, an assessment of wake steering gain and optimum yaw offset angles for each wind turbine are simulated for an operational wind farm. Wake losses are simulated for the wind farm and are validated using historical power measurements. Data analysis procedures for implementing operational wind farm data for the wake steering approach are described. Optimum yaw offset angles are calculated in simulations using operational data. A lookup table is generated for the optimum yaw angles required for each wind direction and speed bin. Using 5-year-long operational data, an average of 0.48% wake losses are calculated for the site. FLORIS simulations suggest 9.6% possible power improvement in wake losses using the optimum yaw offset angles. Using SCADA measurements for potential wake steering assessment allows rapid assessment and implementation without requiring expensive and year-long LIDAR or meteorological mast tower measurements.Master Thesis Short-Term Wind Speed and Power Forecasting: a Comprehensive Case Study for Three Operational Wind Farms(01. Izmir Institute of Technology, 2022) Yoldaş, İrem Selen; Bingöl, FerhatWind energy is gradually growing with the increasing energy demand. However, the rising wind power penetration into modern grids could seriously affect the safe operation of power systems and power quality due to the intermittence and randomness of wind characteristics. Several effective ways could be considered to mitigate these issues: a robust power grid, energy storage, and wind power forecasting. Optimal integration of wind energy into power systems calls for high-quality wind power predictions. This research focuses on the short-term forecast of wind speed and power generation. Firstly, wind speed forecasting is studied. A case study is performed to analyze the forecasting performance of five approaches: the multivariate Facebook Prophet, seasonal autoregressive integrated with moving average (SARIMA), SARIMA with exogenous variable (SARIMAX), gated recurrent units (GRU) and long short-term memory (LSTM). The performance indicators are applied to verify the effectiveness of models, which are R-square (R2), mean square error (MSE), root mean square error (RMSE), and mean absolute error (MAE). The predictions obtained by the LSTM model almost coincide with the real-time wind speed, which is also supported by the performance indicators, which indicate that the LSTM model outperforms the other methods for the real-time dataset of IZTECH meteorological mast. The second part of the study is to forecast the wind power generation using the LSTM model and the wind speed forecasts and wind speed power curve of wind turbines in the wind farms. The proposed model is validated using the real-time wind power generation data from the EPIAS Transparency Platform. Due to the unavailable meteorological dataset, an ERA5 dataset of the location is used to predict wind speed and power generation. Also, each wind farm's daily forecasts are obtained to investigate the results for Day-ahead Market. The results indicate that using the LSTM model with the ERA5 dataset could give better forecasts than wind farms’ own forecasts. Additionally, it is understood that if the SCADA data could be obtained, the forecasting performance might be increased.Master Thesis Coupled Wake and Blockage Modelling for a Wind Farm(Izmir Institute of Technology, 2022) Çam, Janset Betül; Bingöl, FerhatOne of the significant reasons for the power loss in wind farms is the wake effect. Therefore, the wake effect is crucial for designing a wind farm. However, only wake modeling is not sufficient to explain power losses. Wake is the turbulent, complex, and relatively weak flow behind the wind turbine. The wake effect is not required for the front row turbines in wind farms, and the wake model cannot be applied. It is assumed that the wind farm directly encounters the free stream wind speed. However, the blockage effect, also known as the induction zone effect, is observed at the front of the wind turbines. Due to this effect, the wind farm encounters a lower wind speed than the free-stream wind speed. This situation reduces the accuracy of the Annual Energy Production (AEP) calculation in wind farms. The motivation of this study is to obtain an improved coupled wake and blockage model that converges to the accurate SCADA data of a wind farm more than the wakeonly or blockage-only models. This study applies seven wake and six blockage models to the wind farm. The similarities and differences between the coupled models and the wind farm SCADA data and their reasons are discussed.Master Thesis Wind Turbine Power Curve Update Based on Atmospheric Conditions and Structural Fatigue(Izmir Institute of Technology, 2020) Demir, Erdem; Bingöl, Ferhat; Gökçen Akkurt, GüldenWind energy is still developing industry and people who work in this industry working hard to accomplish the difficulties. Problems are not arise only by nature of wind but technological developments, methods and even market pressure itself. Wind turbine theoretical power curves are given only for certain conditions and one can easily say that those conditions are not met in real sites. This difference generates a uncertainty in AEP calculations thus financial models become less reliable. Shifting power curve by taking atmospheric effects into account will give more realistic power curve thus more accurate AEP and financial models. In this study, effects of atmospheric conditions and correction methods on NREL 5MW wind turbines power curve have been investigated and importance of corrected power curve has been discussed.Master Thesis Frequency Control in an Isolated Power System With High Penetration of Wind Power(Izmir Institute of Technology, 2019) Hassan, Ali; Bingöl, Ferhat; Altın, MüfitAs the percentage of wind energy in global energy portfolio rises, the wind turbine control is becoming increasingly important for the integration of wind turbines in power systems. The early control objective of wind turbine control was only to maximize the power output but now the wind turbines are required to provide frequency control as well. To emulate the inertia response (IR) of the conventional synchronous machines the wind turbines can be provided with an inertia emulation controller. The modelling work presented in this thesis aims at equipping the modern Type D wind turbine with inertia response and primary frequency control capabilities. Two controllers — inertial and droop, are implemented and their frequency control capabilities are compared in an isolated power system consisting of a conventional steam turbine generator and a wind farm. A model of one Type D wind turbine is simulated and aggregated for the whole wind farm. The ability of wind turbines to provide inertial response (IR) and primary frequency control (PFC) after a frequency deviation shows a better performance than the case when there is no contribution to frequency control through wind turbines.Master Thesis Length Scale Parameterization and Stability Analyses With Different Statistical Methods in Wind Measurements(Izmir Institute of Technology, 2018) Tuna, Faruk; Bingöl, FerhatWhen there is an attempt to find vertical wind speed and temperature profile in the absence of stability analysis then the bias is observed in those profiles. Wind profile shape can be estimated from the logarithmic wind speed formula under neutral condition since the diabatic stability term omits at that time and on the contrary, for other stability classes, this term should be derived by numerically or analytically, otherwise, the bias will be increased for wind speed and vertical temperature profiles. In this study, the goal is to give different models and options for the masts where stability analysis can’t be done by using data where comes from conventional masts. Here, different 2 kinds scenarios will be given to see better: Scenario 1: No stability analysis applied. Conventional mast measurements are used where the wind speed measurements are at two different heights, the temperature is from only one location, and wind direction measurements are from wind vanes. Therefore, unwanted occasions occur such as overestimate and underestimate for unstable and stable conditions, respectively. Scenario 2: Stability analysis applied by using the sonic anemometer which provides high-frequency data and vertical wind velocity. After determining diabatic wind term, wind speed can be corrected by implementing diabatic term into profile equation. As a summary, those two scenarios are compared and in order to get correct measurements different models for the conventional masts are given.Master Thesis Hybrid Energy Capacity of Turkey for Small and Micro Scale Energy Production(Izmir Institute of Technology, 2017) Yıldız, Mustafa; Bingöl, Ferhat; Gökçen Akkurt, GüldenTurkish state has opened a new possibility on investing small or micro scale energy production without license in 2014. This is a new step in Turkish energy market and two renewable energy sources are considered to be the main interest; wind and solar. Although there are studies covering both technology separately, currently there is no hybrid system assessment methodology and results for the country. This thesis aims to create a quantified hybrid energy capacity of Turkey. The study will include total energy capacity of a given location based on small scale wind and solar and furthermore would be able to suggest an optimum balance between these two sources to get the maximum production capacity out. The study does not cover areas that such investment cannot be done; environmental protected areas, historical places, city centers etc.Master Thesis Wind Atlas of Bay of Bengal With Satellite Wind Measurment(Izmir Institute of Technology, 2016) Nadi, Navila Rahman; Bingöl, FerhatThe objective of this study is to obtain appropriate offshore location in the Bay of Bengal, Bangladesh for further development of wind energy. Through analyzing the previous published works, no offshore wind energy estimation has been found here. That is why, this study can be claimed as the first footstep towards offshore wind energy analysis for this region. Generally, it is difficult to find offshore wind data relative to the wind turbine hub heights, therefore a starting point is necessary to identify the possible wind power density of the region. In such scenario, Synthetic aperture radars (SAR) have proven useful. In this study, SAR based dataset- ENVISAT ASAR has been used for Wind Atlas generation. Furthermore, a comparative study has been performed with Global Wind Atlas (GWA) to determine a potential offshore wind farm. Additionally, the annual energy production of that offshore windfarm has been analyzed by combining SAR, GWA and ASCAT datasets. Through ASAR based Wind Atlas and GWA comparison, some differences has been found as less sampled ASAR datasets were achieved for some nodes. Thus, Weibull statistical analysis are performed to have a better Weibull fitting and accurate estimation of Annual Energy production (AEP). The study summarizes that, satellite datasets can be a very useful method to detect potential zone if compared with any long time statistical result and bathymetry data together. In this study, all three datasets comprises similar AEP at the coastal area which indicates beneficiary pace for future wind energy sector of Bangladesh.Master Thesis Modelling and Fitting of the Wind Data Using Different Time Series Models and Investigating the Relared Applications of Fitted Data. Urla and Risø Cases(Izmir Institute of Technology, 2014) Yıldırım, Nurseda; Duran, Hasan Engin; Bingöl, FerhatThis thesis is prepared as an outcome of Energy Engineering Master of Science program at IZTECH. Main purpose of this study is to investigate the possible ways of estimating the evolution of wind speed in Turkey, which is useful in predicting the wind power generation. Wind Energy has recently been recognized as one of the most promising renewable energy sources in the world. Despite its high potential, one major problem is that it is an intermittent energy source which follows, in general, statistically a quite noisy evolution with large variability and difficulty in forecasting. Standard time series models have been employed to forecast the wind speed in the literature (such as ARIMA, ARMA). The majority of these, however, are based on a univariate modelling. This is likely to create a significant loss in forecast accuracy as the important dynamics of wind such as ambient temperature, absolute pressure, wind direction and humidity are ignored. So, aim of the present study is to incorporate these factors in a multivariate VAR setting and estimate the wind speed in 4 different locations around Urla City (nearby Izmir-Turkey) by employing hourly data between June-2000 and October-2001. To provide a benchmark, I also compare estimations from VAR with the predictions from ARIMA and SARIMA models. The results indicate two important conclusions. First, it has been shown that all models provide an accurate estimate of wind speed. Second, multivariate VAR and SARIMA is clearly shown to outperform the ARIMA model by improving the wind speed predictions and producing less forecast errors. Thus, these models are demonstrated to be helpful in estimating the wind power generation as well.