18 research outputs found
Mycielski approach for synthetic wind speed data generation
No full text2009 IEEE 17th Signal Processing and Communications Applications Conference, SIU 2009 -- 9 April 2009 through 11 April 2009 -- Antalya -- 77539In this paper, a novel Mycielski based approach for wind speed data generation is developed and presented. The efficincy of the proposed approach is tested using hourly wind speed data obtained from İzmir region. To test the efficiecy of the approach, the four year - long measured data are seperarted into two parts: data belonging to first three years are used for training whereas the remaining one - year data are used for testing and accuracy comparison purposes. In order to compare the efficiency of the proposed generation method, the same data are used in artificial wind speed generation with the classical method of first order Markov chains. Results indicate that the proposed Mycielski based algorithm produces better quality artificial data as compared to previous method
Mycielski approach for wind speed prediction
No full textWOS: 000266153800005Wind speed modeling and prediction plays a critical role in wind related engineering studies. However, since the data have random behavior, it is difficult to apply statistical approaches with apriori and deterministic parameters. On the other hand, wind speed data have an important feature; extreme transitions from a wind state to a far different one are rare. Therefore, behavioral modeling is possible. Although several studies focus on global parametrization of wind data behavior, the literature in time-wise modeling and prediction is relatively small. In this study, a novel approach for wind speed modeling using the Mycielski algorithm is demonstrated. The algorithm accurately predicts the time variations of wind speed data in the sense of forecasting future values of wind data by analyzing the repeatedness in the history of the data. The prediction precision of the procedure is tested using wind speed data obtained from three different locations of Turkey (Kayseri, Izmir and Antalya). Prediction results with high accuracy are obtained and presente
Emission and in-cylinder combustion characteristics of a spark ignition engine operated on binary mixtures of gas and liquid fuels
No full textIn this study, three different gas fuels such as hydrogen, propane, methane and six different liquid fuels such as, benzene, gasoline, toluene, hexane, methanol and ethanol have been combined and combustion characteristics have been simulated for a spark ignition engine (SIE). Variation of in-cylinder temperature, in-cylinder pressure, CO, CO2 and NO has been investigated. The gas fuel ratios in the mixtures were changed between 0 and 100% by mass. It was investigated that how the addition of gaseous fuels to liquid fuels at different ratios affects the combustion characteristics and emission formation. The gas fuel ratios considerably affected emission and combustion specifications of the engine. Increasing liquefied gas fuel ratio in the mixture leads to decrement in the temperature of charge. The maximum pressure first increases with increasing gas fuel ratio and then start to minimize after maximum pressure. The maximum peak pressure values are observed at 50% gasoline and 50% methane, 75% gasoline and 25% propane, 50% gasoline-50% hydrogen as 48.1 bar, 46 bar and 62.4 bar for different gas fuel mixtures. The minimum peak pressure value is displayed at 100% methanol as 44.06 bar. The maximum temperature value is observed at 100% benzene as 2582 K and its minimum value seems at 100% hydrogen as 2059 K. The maximum mass fractions of CO, CO2, NO are observed at 100% benzene as 0.0271, 0.161, 0.0076, the minimum mass fraction of CO2 is observed at 100% methane as 0.095. The minimum mass fraction of CO is observed at 100% methanol as 0.01243. The minimum mass fraction of NO is observed at 100% hydrogen as 0.00085. The fuels are ranked using a multi-criteria decision-making algorithm called AHP after evaluating the values of all performance criteria and their respective sub-criteria, including in-cylinder pressure, in-cylinder temperature, NO, CO2 and CO to get preference rank between fuels
A 2 dimensional solar radiation model
No full text2008 IEEE 16th Signal Processing, Communication and Applications Conference, SIU -- 20 April 2008 through 22 April 2008 -- Aydin -- 74111In this study solar radiation data obtained from Eskisehir region is mathematically modeled using a two dimentional (2D) approach. The approach and model is novel in the literature of solar radiation modeling. The analysis is based on mathematical behavior of hourly and daily behavioral cross-sections of the 2D data. It is observed that the deviation of the hourly data within a day exhibits a Gaussian shape, and the deviation of daily data in the year has a sinusoidal behavior. The hourly behaviour of daily data is tested by single and double Gaussian source models, whereas the daily behavior of yearly data is only modeled using sinusoidal function. By this way two different equations corresponding two different surfaces are obtained. It is concluded that single-source Gaussian surface represents the data more accurate than two dimentional Gasussian surface. Consequently, a very simple but an accurate 2D model is obtained for solar radiation dat
Regional Wind Energy Resource Assessment
No full textWOS: 000277508200004In this study, using the Wind Atlas Analysis and Application Program (WAsP) software the wind statistics and energy calculations are performed for Eskisehir region. Suitable sites to locate wind turbines optimally are selected according to the created wind power and wind speed maps. Eighteen different wind turbines with nominal powers between 200 and 2,000 kW are established for annual energy production calculations and the best-fitted three types of turbines of which capacity factors are bigger than 30% are used for the micrositting. Wind farms with a total of 20 wind turbines each are built in three different suitable locations by using each selected type of wind turbines. Furthermore, the energy productions of the wind farms are calculated
A Preliminary Detailed Study on Constructed Hybrid (Wind-Photovoltaic) System under Climatically Conditions of Eskisehir Region in Turkey
No full text1st International Power and Energy Conference, PECon 2006 -- 28 November 2006 through 29 November 2006 -- Putrajaya -- 72409Wind and solar power provide a clean energy resource and are promising in the short term in Turkey. In this study, the usage of wind and solar energy to produce electricity and the possibility of electrical energy production from wind and sun hybrid energy systems in the region of Eskisehir for application purposes has been studied. First, a wind and sun observation station was founded at the Anadolu University Iki Eylül Campus, and data were collected for 6 months to determine the wind energy potential. Values from the established measurements are searched to determine whether electricity production from the wind and solar energy is feasible. Also a hybrid (Wind-Solar) Energy Production System Model is constructed and economical analysis for the given period was made. It is aimed that by using this model the bigger systems analysis can be don
Wind speed prediction with Mycielski algorithm
No full text2009 IEEE 17th Signal Processing and Communications Applications Conference, SIU 2009 -- 9 April 2009 through 11 April 2009 -- Antalya -- 77539Rüzgar hız tahmini, rüzgar ile ilgili mühendislik
problemlerinde önemli bir yer tekil eder. Fakat her
meteorolojik olay gibi rüzgar da rastsal davranışlar
sergilemektedir. Dolayısıyla bilinen istatistiksel yöntemlerle
duyarl bir rüzgar hız tahmini yapmak oldukça zordur. Buna rağmen rüzgar davranışlarının önemli bir karakteristi i
vard r: Rüzgarlar n herhangi bir rüzgar hız durumundan
bundan çok farklı bir rüzgar hız durumuna geçmesi olası
oldukça düşüktür. Bu karakteristik rüzgar içinde incelenmesi
gereken örüntülerin olu mas na neden olur. Bu çal mada
rüzgar içindeki örüntüleri incelememizi sa layacak, Mycielski
algoritması kullanan yeni bir tahmin yöntemi önerilmiş tir.
Önerilen algoritmada rüzgar verisinin geçmişi
incelenmektedir. Geçmişte farklı yerlerde tekrar eden olası en
uzun örüntüler algılamakta ve geçmişin tekrar edeceği
varsayımından yola çıkarak tahmin yapılmaktadır. Önerilen
yöntem İzmir ve Antalya bölgelerinden ölçülmü rüzgar
verileri üzerinde denenmiştir.Başarılı sonuçlar elde edilmiş ve
ayrıntılı bir şekilde tartılşıltır.Wind speed prediction is an important issue in wind related
engineering studies. However, the wind data has random
behavior like other meteorological events. Therefore, it is
difficult to apply conventional statistical approaches. On the
other hand, wind speed data has an important feature; large
fluctuations from a wind state to a significantly different level
is relatively seldom. This feature leads to some patterns that
should be exemined in detail. In this study, a novel approach
for wind speed modeling using Mycielski algorithm that
considers this important future is demonstrated. Developed
procedure, predicts future values of wind data by analysing
repeatings in the history of data and assumes that the history
will be structurely repeated in the future. The prediction
capability of the procedure is tested using wind speed data
obtained from 2 cities in Turkey: zmir and Antalya.
Reasonable prediction results are obtained and analysis results
are reported
A novel hybrid (wind-photovoltaic) system sizing procedure
No full textWOS: 000271158600008Wind-photovoltaic hybrid system (WPHS) utilization is becoming popular due to increasing energy costs and decreasing prices of turbines and photovoltaic (PV) panels. However, prior to construction of a renewable generation station, it is necessary to determine the optimum number of PV panels and wind turbines for minimal cost during continuity of generated energy to meet the desired consumption. In fact, the traditional sizing procedures find optimum number of the PV modules and wind turbines subject to minimum cost. However, the optimum battery capacity is either not taken into account, or it is found by a full search between all probable solution spaces which requires extensive computation. In this study, a novel description of the production/consumption phenomenon is proposed, and a new sizing procedure is developed. Using this procedure, optimum battery capacity, together with optimum number of PV modules and wind turbines subject to minimum cost can be obtained with good accurac
Effects of Temperature and Pressure Information in a Hybrid (Fourier Series / Neural Networks) Solar Radiation Model
No full textNational Science Council;Ministry of Education;Kaohsiung City Government;National Applied Research Laboratories;IEEE Tainain Section2009 4th International Conference on Innovative Computing, Information and Control, ICICIC 2009 -- 7 December 2009 through 9 December 2009 -- Kaohsiung -- 79888Solar radiation modeling is a critical step in efficient management of solar energy. In this study, a novel solar radiation modeling procedure is developed with the a-priori information of temperature and pressure values, which are naturally dependent on solar radiation via indirect atmospheric phenomena. Firstly, daily behavior of hourly solar radiations is considered in frequency domain. Initial nine Fourier series coefficients are calculated for each day. Secondly, various neural networks models are built for prediction of these nine Fourier coefficients using the input data gathered from early morning hours and previous day. Apart from the solar radiation readings, temperature and pressure data are also used for developing a more accurate model. It is concluded that, the support of temperature and pressure data of the region improves the solar radiation model. Finally, differences between the performances of the proposed models reveal correlative relationships between atmospheric parameters and solar radiatio
Potential Analysis of Wind Energy as a Power Generation Source
No full textWOS: 000277508200002Wind energy as a power generation source is one of the most significant and rapidly developing renewable energy sources in the world. Because wind energy potential in various parts of Turkey is becoming economical, it is necessary to determine to start the immediate usage of the wind energy potential and the investigation of the necessary techniques and economic feasibility. In this study, wind energy status in Turkey is examined briefly and the possible wind energy potential in Eskisehir, Turkey is investigated using the data collected in the observation station established at Iki Eylul Campus of Anadolu University between the dates of July 1, 2005 and September 30, 2006.Anadolu University of Scientific Research Project Fund [2004/040258]The author gratefully acknowledges the Anadolu University of Scientific Research Project Fund for the financial support of this work through project 2004/040258
