다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

http://ieeexplore.ieee.org/iel5/5610941/5624686/05624745.pdf

Power electronics

Thyristor-Based FACTS Controllers for Electrical Transmission Systems

This paper discusses the power quality issues for distributed generation systems based on renewable energy sources, such as solar and wind energy. A thorough discussion about the power quality issues is conducted here. This paper starts with the power quality issues, followed by discussions of basic standards. A comprehensive study of power quality in power systems, including the systems with dc and renewable sources is done in this paper. Power quality monitoring techniques and possible solutions of the power quality issues for the power systems are elaborately studied. Then, we analyze the methods of mitigation of these problems using custom power devices, such as D-STATCOM, UPQC, UPS, TVSS, DVR, etc., for micro grid systems. For renewable energy systems, STATCOM can be a potential choice due to its several advantages, whereas spinning reserve can enhance the power quality in traditional systems. At Last, we study the power quality in dc systems. Simpler arrangement and higher reliability are two main advantages of the dc systems though it faces other power quality issues, such as instability and poor detection of faults.

https://vbn.aau.dk/ws/files/294611667/08314672.pdf

Analysis and Mitigation of Power Quality Issues in Distributed Generation Systems Using Custom Power Devices

An improved residual-based convolutional neural network for very short-term wind power forecasting

Dynamic Performance Comparison of PD and PD-Fuzzy Logic Controllers for Inverted Pendulum System

This study aims to seasonally examine run-of-river type hydroelectric power plants' ramp rates (generation changes) (RoRHPP). Turkey RoRHPP generations were obtained for this objective between 01 December 2020 and 01 December 2021. Obtained data are hourly resolution and belong to 560 plants. The total installed power of the plants used in work is 7897.06 MW. This study used histogram fields to examine ramp rates of 5%, 7.5%, and 10% of the installed power in 1, 3, and 6-hour periods. As a result of the investigations, the cumulative histogram areas of the ramps of 5% and above in 6 hours temporal periods of the spring, summer, autumn, and winter seasons were calculated as 39430.94, 22117.72, 17811.76, and 34914.32, respectively. When these ramps are evaluated according to their directions, the histogram areas of positive ramp (generation increase) in spring, summer, autumn, and winter are 20052.1, 10945.74, 9095.8, and 17303.19, respectively. The histogram areas of the negative ramps (reduction of generation) in spring, summer, autumn, and winter are 19378.84, 11171.98, 8715.96, and 17611.13, respectively. According to all these results, ramp events in Turkey's RoRHPP productions occurred the most in the spring. In addition, It was also concluded that positive ramp events occurred more in all seasons.

/pdf/seasonal-assessment-of-run-of-river-hydroelectric-power-uhshy471.pdf

Seasonal assessment of run-of-river hydroelectric power plant ramp events

Turkiye cografi konumu nedeniyle buyuk bir gunes enerjisi potansiyeline sahiptir ve ulkedeki Gunes Enerjisi Santrali (GES) kurulu gucu hizla artmaktadir. Fakat GES uretimlerindeki degiskenlik bu tesislerin elektrik sebeke sisteminde isletilmesini problem haline getirmektedir. Bu problemin giderilmesi icin GES uretim tahminlerine ihtiyac duyulmaktadir. Bu calismada GES uretimleri icin bir tahmin sistemi onerilmistir. Onerilen tahmin sisteminde Yapay Sinir Aglari (YSA) kullanilmistir. YSA Levenberg-Marquardt ogrenme algoritmasi kullanilarak egitilmistir. YSA egitim, dogrulama ve test sureclerinde Kahramanmaras ilinde yer alan GES gecmis uretim degerleri ve Kuresel Tahmin Siteminden (KTS) alinan bulutluluk tahmin verileri kullanilmistir. YSA yapisi ve giris degerleri degistirilerek analizler yapilmistir. Yapilan analizler sonucunda giris olarak uretim degerleri ile birlikte bulutluluk tahmini kullanan YSA’nin sadece gecmis uretim degerleri kullanilan YSA’ya kiyasla daha basarili oldugu tespit edilmistir.

/pdf/yapay-sinir-aglari-kullanarak-kisa-donem-gunes-enerjisi-fsjjqjxlcx.pdf

Yapay Sinir Ağları Kullanarak Kısa Dönem Güneş Enerjisi Santrali Üretim Tahmini: Kahramanmaraş Örnek Çalışması

Optimal scheduling of active electricity distribution network at feeder scale under possible conditions and considering operating cost

Day-ahead electricity market (DAM) price forecasts are crucial parameters for market participants to create their next – day generation plan. Accurate price forecasts help participant companies to increase their profit by shifting generation to high price occurred hours. In this study we developed a forecast model for Turkish energy market because country’s energy market mechanism hasn’t got price forecast module and there is no available accurate price forecasts. Architecture of model is based on feed forward back propagation neural network approach. Four year period real market data are used in train and test phases. Results of this study show that forecasts of proposed model have acceptable accuracy and the performance of the model strongly depends on the market demand and generation capacities.

/pdf/price-forecasting-model-for-turkish-day-ahead-electricity-5csrjce3xe.pdf

Mustafa Şekkeli

Papers

Dynamic Performance Comparison of PD and PD-Fuzzy Logic Controllers for Inverted Pendulum System

Seasonal assessment of run-of-river hydroelectric power plant ramp events

Yapay Sinir Ağları Kullanarak Kısa Dönem Güneş Enerjisi Santrali Üretim Tahmini: Kahramanmaraş Örnek Çalışması

Optimal scheduling of active electricity distribution network at feeder scale under possible conditions and considering operating cost

Price Forecasting Model for Turkish Day-Ahead Electricity Market Using Neural Network