Cenk Gezegin
@omu.edu.tr
Electrical Electronics Engineering
Ondokuz Mayıs Üniversitesi Elektrik Elektronik Mühendisliği
RESEARCH, TEACHING, or OTHER INTERESTS
Electrical and Electronic Engineering, Renewable Energy, Sustainability and the Environment
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Abdulkadir Gozuoglu, Okan Ozgonenel, and Cenk Gezegin
Elsevier BV
Chafak Tarmanini, Nur Sarma, Cenk Gezegin, and Okan Ozgonenel
Elsevier BV
Hasan DİRİK, Cenk GEZEGİN, and Hasan Serdar DİRİK
Elsevier BV
Kubra Nur Akpinar, Burcu Gundogdu, Okan Ozgonenel, and Cenk Gezegin
Elsevier BV
Secil Genc, Nur Sarma, Burcu Gundogdu, Okan Ozgonenel, Cenk Gezegin, and Umit Kemalettin Terzi
IEEE
The fundamental issue with high switching power converters is electromagnetic interference. The converter design must be electromagnetically compliant for an operation to be secure. Filters play a crucial role in mitigating electromagnetic interference (EMI) within three-phase systems. This paper presents examining the electromagnetic interference associated with a three-phase inverter interconnected to the grid. The reported measurements were taken after the filter and applied with three-phase adjustable drive system for 9-150kHz frequency ranges. Therefore, experimental evidence supports the EMI filter's noise attenuation. In conclusion, the presented study fills in the gaps measuring uncertainties for three-phase emissions, assisting engineers in the design of three-phase converters.
Shir Ahmad Dost Mohammadi and Cenk Gezegin
Springer Science and Business Media LLC
Cenk Gezegin, Okan Ozgonenel, and Hasan Dirik
Institute of Electrical and Electronics Engineers (IEEE)
Transformers are the most expensive element of a power system, and so transformer monitoring systems are becoming more important as loads increase. Under heavy loading conditions, the hot-spot temperature of a transformer is the most critical parameter to determine the limit of loading. Therefore, to make an accurate estimation of hot-spot temperature and maintain the reliability of a power system, dynamic thermal models or methods must be employed. Due to the complexity of thermal phenomena, the methods presented so far needs to be improved to reduce computational errors. This is particularly the case for variable loading conditions and power utilities are still in need of good techniques. This paper describes two methods to determine temperature in single-phase, oil-immersed transformers. The first method calculates average windings temperature (AWT) using the voltage and current from primary and secondary windings. The second method, which uses data from the first method, determines the hot-spot temperature of the transformer. The methods have been investigated by experiments on a 30 kVA single-phase transformer and verified the results using COMSOL ™ software. Our methods have proven more accurate than the IEEE Annex G method.
Hasan Dirik, Ismail Umut Duran, and Cenk Gezegin
Institute of Electrical and Electronics Engineers (IEEE)
As the ratio of nonlinear loads fed from grids are increasing day by day, harmonic pollution problems seem to be more and more serious. Problems related to harmonics are the main sources of economic losses at power systems. In order to reduce economic losses and provide cleaner grids, utilities need to find new and reasonable ways to control harmonic pollution. A proper way of this is to enforce monetary sanctions to the consumers who are responsible for harmonic pollution. With this way, consumers are encouraged to take necessary actions for reducing their harmonic emissions. However, utilities still need a fair, reasonable, and applicable method for this aim to control harmonic emissions of costumers. In this context, a new method to compute the contribution of individual customers to harmonic pollution of grids is presented in this paper. For this aim, an index representing the harmonic emission level of loads is defined. In the development of the method, responsibilities of utilities and consumers, harmonic limits specified by standards and effects of each harmonic component on grid elements have been especially taken into account. Thus, it has been possible to form a fair, reasonable, and applicable method. Validity of the method is tested by simulations, and results are discussed. At the end of this paper, an experimental setup designed for real-time metering is also presented. This demonstrated the applicability of such a metering device that uses the proposed method.
Hasan Dirik, Cenk Gezegin, and Muammer Ozdemir
Institute of Electrical and Electronics Engineers (IEEE)
Equivalent circuit parameters of transformers are related to the condition of their windings. Information concerning winding deformations, failures, and temperature can be acquired by monitoring these parameters. Methods used for the determination of electrical parameters generally require disconnection of the transformer from the power system. In this paper, a novel method which uses real-time data of the transformer to determine its parameters is presented. Therefore, this method eliminates the need for the disconnection of the transformer from the power system. In the method, winding parameters are obtained by applying the differential equation algorithm to the fundamental frequency components of transformer data. Fundamental frequency components of the currents and voltages are computed by using the discrete cosine transform. Transformer core parameters are also computed via core losses and the polynomial curve-fitting method with the least squares error method. The proposed method has been tested and validated by simulations and experiments.