Browsing by Author "Yilmaz, Ahmet S."

Now showing 1 - 3 of 3

Citation - WoS: 47
Citation - Scopus: 57
Applications of parametric spectral estimation methods on detection of power system harmonics
(Elsevier Science SA, 2008) Ahmet Serdar Yilmaz; Ahmet Alkan; Musa Hakan Asyali; Alkan, Ahmet; Asyali, Musa H.; Yilmaz, Ahmet S.
Harmonics are the major power quality problems in industrial and commercial power systems. Several methods for detection of power system harmonics have been investigated by engineers due to increasing harmonic pollution. Since the non-integer multiple harmonics (inter and sub-harmonics) become wide spread the importance of harmonic detection has increased for sensitive filtration. This paper suggests parametric spectral estimation methods for the detection of harmonics inter-harmonics and sub-harmonics. Yule Walker Burg Covariance and Modified Covariance methods are applied to generate cases. Not only integer multiple harmonics but also non-integer multiple harmonics are successfully determined in the computer simulations. Further performances of proposed methods are compared with each other in terms of frequency resolution. © 2007 Elsevier B.V. All rights reserved. © 2008 Elsevier B.V. All rights reserved.
Citation - WoS: 44
Citation - Scopus: 62
Frequency domain analysis of power system transients using Welch and Yule-Walker AR methods
(PERGAMON-ELSEVIER SCIENCE LTD, 2007) Ahmet Alkan; Ahmet S. Yimaz; Alkan, Ahmet; Yimaz, Ahmet S.; Yilmaz, Ahmet S.
In this study power quality (PQ) signals are analyzed by using Welch (non-parametric) and autoregressive (parametric) spectral estimation methods. The parameters of the autoregressive (AR) model were estimated by using the Yule-Walker method. PQ spectra were then used to compare the applied spectral estimation methods in terms of their frequency resolution and the effects in determination of spectral components. The variations in the shape of the obtained power spectra were examined in order to detect power system transients. Performance of the proposed methods was evaluated by means of power spectral densities (PSDs). Graphical results comparing the performance of the AR method with that of the Welch technique are given. The results demonstrate superior performance of the AR method over the Welch method. (c) 2007 Elsevier Ltd. All rights reserved.
Citation - Scopus: 45
Long term energy consumption forecasting using genetic programming
(Association for Scientific Research, 2008) Ahmet S. YILMAZ; Ahmet Alkan; KORHAN KARABULUT; Alkan, Ahmet; Yilmaz, Ahmet S.; Karabulut, Korhan
Managing electrical energy supply is a complex task. The most important part of electric utility resource planning is forecasting of the future load demand in the regional or national service area. This is usually achieved by constructing models on relative information such as climate and previous load demand data. In this paper a genetic programming approach is proposed to forecast long term electrical power consumption in the area covered by a utility situated in the southeast of Turkey. The empirical results demonstrate successful load forecast with a low error rate.