Browsing by Author "Papadopoulos, Theofilos A."

Now showing 1 - 3 of 3

Citation Count: 1
Active and Reactive Power Load Profiling Using Dimensionality Reduction Techniques and Clustering
(Institute of Electrical and Electronics Engineers Inc., 2019) Ceylan, Oğuzhan; Ceylan, Oğuzhan; Papadopoulos, Theofilos A.; Kazaki, Anastasia G.; Barzegkar-Ntovom, Georgios A.
This paper proposes a methodology to characterize active and reactive power load profiles. Specifically, the approach makes use of fast Fourier Transform for conversion into frequency domain, principle component analysis to reduce the dimension and K-means++ to determine the representative load profiles. The data set consists of five-year measurements taken from the Democritus University of Thrace Campus. Test days were also classified as working and non-working. From the results it is observed that the proposed methodology determines representative load profiles effectively both regarding active and reactive power.
Citation Count: 4
Generic dynamic load modelling using cluster analysis
(IEEE, 2018) Ceylan, Oğuzhan; Ceylan, Oğuzhan; Papadopoulos, Theofilos A.; Yetkin, E. Fatih
In this paper a new generic load modelling procedure is proposed based on the application of cluster analysis on load model parameters identified from measured dynamic responses. The performance of the proposed approach is assessed using measurements obtained from a low-voltage laboratory scale test configuration. In order to develop robust generalized load models applicable to a wide range of operating conditions different load compositions operating conditions and voltage disturbances are considered in the analysis. The findings of this paper verify the validity of the proposed generic modelling procedure and indicate robust results using the proposed methodology.
Citation Count: 0
Two-layer earth structure parameter estimation and seasonal analysis
(IEEE, 2018) Ceylan, Oğuzhan; Ceylan, Oğuzhan; Papagiannis, Grigoris K.
The determination of soil parameters is an important topic regarding the safe and efficient design of electrical grounding systems as well as the accurate calculation of the per-unit-length parameters of overhead transmission lines and underground cable systems. Scope of this paper is to investigate the seasonal variation of the two-layer earth structure parameters and propose simple generic models for this type of the analysis. For the determination of the two-layer earth parameters the application of different optimization methods is evaluated. Furthermore soil resistivity measurements are conducted at three different sites during a period of a whole year. The obtained results of the two-layer earth structure are analyzed in order to investigate the seasonal variation and their correlation to changes of rainfall. From the analysis of the results significant conclusions are drawn regarding the accuracy of the resulting soil parameters as well as their annual variation.