Thermal analysis of power cables

Güven, Oytun
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 capacities of various types of cables are determined using dissipated heat values.


Prediction of hot-spot and top-oil temperatures of power transformers according to IEEE standards C57.110-1998 and C57.91-1995
Karaca, Haldun; Ermiş, Muammer; Department of Electrical and Electronics Engineering (2007)
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 meas...
Reduction of switching overvoltages by means of controlled switching
Güneri, Melih; Özay, Nevzat; Department of Electrical and Electronics Engineering (2006)
This thesis analyses the controlled switching methods applied to modern SF6 type circuit breakers for the purpose of reducing switching overvoltages. Main emphasis is placed on controlled switching methods applied at extra high voltage level, since the cost of failures caused by switching overvoltages is highest in this voltage level. After a brief introduction about circuit breakers in general, switching overvoltages and controlled switching methods are analysed. Also a case study about controlled switchin...
Development of algorithms for fault detection in distribution systems
Ersoi, Moustafa; Özay, Nevzat; Department of Electrical and Electronics Engineering (2003)
In this thesis, the possibility of detection of fault location in the cable distribution systems by using traveling waves due to fault and circuit breaker operations is investigated. Waveforms originated from both actions and fault steady state are separately analyzed. During such switching actions, high frequency variations which are absent in the steady state conditions, take place. In order to simulate high frequency changes properly, system elements are modeled accordingly. In other words, frequency dep...
Fault detection and service restoration in medium voltage distribution system
Altın, Müfit; Özay, Nevzat; Department of Electrical and Electronics Engineering (2009)
This thesis proposes an algorithm and develops a program for fault detection and system restoration in medium voltage distribution systems. In Turkey, TUBITAK-UZAY developed distribution automation system including fault detection and service restoration functions for Bogazici Electricity Distribution Company. By the time, expanding of distribution system with nonstandardized infrastructure (for example more than one circuit breaker in the feeder, mesh and closed loop feeder structure), developed automation...
Calibration of conventional measurement transformers against harmonic components by using field measurements of optical transducers and resistive-capacitive voltage transformers
Türkmen, Coşkun Aziz; Ermiş, Muammer; Department of Electrical and Electronics Engineering (2010)
It is known from the literature that conventional voltage and current transformers measure inaccurate values for voltage and current harmonics which are parts of power quality. Maximum bandwidth of conventional current transformers, which are used in electricity transmission and distribution systems, is 1.5-2 kHz and it is lower for conventional voltage transformers. Also, it is known that; voltages in some frequency spectrum are measured higher and voltages in another frequency spectrum are measured lower ...
Citation Formats
O. Güven, “Thermal analysis of power cables,” M.S. - Master of Science, Middle East Technical University, 2007.