Prediction of hot-spot and top-oil temperatures of power transformers according to IEEE standards C57.110-1998 and C57.91-1995

Karaca, Haldun
In this thesis, the effects of Harmonics on the Top Oil and Hot Spot Temperatures of Power Transformers used in Turkish Electricity Transmission System have been investigated. Due to the solid state equipment, the harmonic levels increase. This effect raises the losses and temperatures in the transformer windings. None of the power transformers currently used in Turkey has measuring equipment suitable for measuring the Hot-Spot temperatures. In this study, a computer program is written in LABVIEW which measures the harmonics and calculates the temperatures in accordance with the methods recommended in IEEE Standards C57.110-1998 and C57.91-1995. Also for sample transformers the work has been verified by measuring the Top-Oil temperatures of the transformers and then comparing with the calculated results.


Determination of optimum values for voltage setpoints of power stations in Turkey
Elma, İsmail; Güven, Ali Nezih; Tör, Osman Bülent; Department of Electrical and Electronics Engineering (2014)
Voltage control is performed in three hierarchical levels in Turkish power system: primary, secondary and tertiary voltage control. Primary and secondary voltage controls are defined as the regulation of the voltage at the generator terminal and at the high voltage busbar of the power plant according to the pre-determined setpoints. The determination of the voltage setpoints for the power plants, which is defined as the tertiary voltage control, is performed by the operators in National and Regional Load Di...
Thermal analysis of power cables
Güven, Oytun; Ertaş, Arif; Department of Electrical and Electronics Engineering (2007)
This thesis investigates temperature distribution and hence heat dissipation of buried power cables. Heat dissipation analysis of a simple practical application and the parameters that affect the heat dissipation are discussed. In analyzing temperature distribution in the surrounding medium , a computer program is developed which is based on gauss-seidel iteration technique. This method is applied to a sample test system and heat dissipation curves for several parameters are obtained. Also, current carrying...
Determination of weak transmission links by cluster analysis
Ertuğrul, Hamza Oğuz; Özay, Nevzat; Department of Electrical and Electronics Engineering (2009)
Due to faults and switching, transmission lines encounter power oscillations referred as power swings. Although in most cases they do not lead to an eventual instability, severe changes in power flows on the lines may cause the operation of impedance relays incorrectly, leading to cascaded tripping of other lines. Out-of-Step tripping function is employed in modern distance relays to distinguish such an unstable swing but setting the parameters and deciding lines to be tripped require detailed dynamic power...
Design and realization of a high voltage radio interference voltage (riv) measurement system
Özer, Mutlu; Hızal, Mirzahan; Department of Electrical and Electronics Engineering (2010)
This thesis aims the design and the realization of a radio noise meter which can be used to measure radio interference of a high-voltage transmission line due to partial discharges like conductor corona. The radio noise meter is the common equipment for radio noise and radio interference voltage measurements. The corona of transmission lines, its characteristics, its effects on radio interference and measurement of corona caused radio noise in the scope of relevant international standards are investigated. ...
Measuring the efficiency of the turkish electric distribution sector using stochastic frontier analysis
Çelen, Aydın; İyigün, Cem; Department of Industrial Engineering (2011)
This study analyzes the technical efficiencies of Turkish electricity distribution companies (21 in total) throughout 2002 and 2009. For this aim, we used six different model specifications, all of which are generated from two different Stochastic Frontier Analysis (SFA) models (Battese ve Coelli (1992&1995)). At the end of the estimations of the models, it has been seen that the signs and significance levels of the coefficient estimations are very consistent and satisfactory in all models. We also observed...
Citation Formats
H. Karaca, “Prediction of hot-spot and top-oil temperatures of power transformers according to IEEE standards C57.110-1998 and C57.91-1995,” M.S. - Master of Science, Middle East Technical University, 2007.