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Bayindir R.,Gazi University | Yesilbudak M.,University of Nevsehir | Cetinkaya U.,Turkish Electricity Transmission Company
2015 International Conference on Renewable Energy Research and Applications, ICRERA 2015 | Year: 2015

In recent years, the increasing electricity demand leads energy operators to new grid investments. On the other hand, electricity grids are constantly extending and include different kinds of generation and consumption sources. In addition, the operating conditions of lines and equipments in the electricity transmission system are changed in consequence of increasing distributed generation resources on the grid. For these reasons, it is required to plan and analyze properly in power system establishments. In this study, the electricity transmission infrastructure of industry regions in Ankara, Turkey is modeled. The usage of large powerful loads, the constantly increasing electricity demand and the increment in microgrid applications are the main reasons for the preference of these industrial areas. In the stage of modeling the electricity transmission system, the actual data of grid, lines, substations and generation plants are used in the DigSilent program. The different case studies depended on load and short-circuit analyses are implemented on the developed grid model. As a result of the conducted case studies, the recent generation and consumption situations, the impacts of microgrids on the existing system and the possible grid reactions for the increasing demand and demand response in future years are evaluated in an effective manner. © 2015 IEEE.

Pamuk N.,Turkish Electricity Transmission Company | Uyaroglu Y.,Sakarya University
Scientific Research and Essays | Year: 2010

Energy is one of the basic data for economic and social development. Sufficient electrical energy, high quality, continuous, low-cost and environmentally compatible manner should be available to consumers. Power system reliability depends on the reliability of the equipments in the system. For this reason, transformers of the power system are the most important equipments. In power transformer, failure rate is quite high compared to that in some parts of the world; and as such, the necessity to work in the best operation case of transformer and preventing transformer failures have obviously emerged. This study proposes the failure of insulating oil in power transformers. However, the electrical and thermal effects of cellulosic materials subjected to degradation have been analyzed in details and these gases emission show different type of failures. Also, these failures are seen in the production rate point to the magnitude of the failures. Analysis of failures using Fuzzy logic computer program have been tried in order to achieve the optimum method of evaluating the causes that play a role in the formation of probable transformer failures. © 2010 Academic Journals.

Pamuk N.,Turkish Electricity Transmission Company | Uyaroglu Y.,Sakarya University
Energy Education Science and Technology Part A: Energy Science and Research | Year: 2012

This paper deals with scenario of cascade failure in a large interconnected grid of Turkey. A single fault seldom leads to the catastrophe like blackout in energy system, but often causes other faults, which result in cascading failures and blackouts. Blackouts are occurred prevalently in huge energy system. Initiator events of these catastrophic failures can be prevented by convenient protection settings. In this study, different cascading failure scenarios are evaluated under credible contingency conditions. The scenarios have been analyzed on the Northwest Anatolia energy system with 118 buses where is the most critical part of Turkey Electricity System. The situation of energy plants and transmission lines in this energy system are analyzed for disability aspects. All energy system components are simulated by means of a power flow analysis performed with the PSS/E software. The power flow map is drawn from simulated data. The results allow us to be better prepared to face these severe disturbances, defining procedures for emergency situation and training the control room operators. © Sila Science.

Power system equipment have conventionally used mineral oil for insulation and cooling. The preferable alloy material has to be generated with good chemical and electrical features. However, recent case has indicated the shortcomings of these fluids where they have poor characteristics particularly at fire and flash point and most significantly poor dielectric malfunction voltage. The most critical of these deficiencies is the disability to meet up with the environmental and health laws. Further, they are not organic and hence not biodegradable. In this study, natural palm oil and its derivatives have been studied in attempt to discover an environmental friendly insulating fluid. Patterns such as crude and refined palm oils were chemically and electrically tested and comparisons were made with the mineral oil. Electrical tests such as the malfunction voltage, power factor and resistivity were pursued. Besides that, chemical characteristics such as water content, kinematic viscosity, moisture content of the alloy, flash point, density, pour point, corrosion, neutralization value and dissolution of gases were also being investigated. Results from the test laboratory studies have indicated that the natural palm oil has preferable chemical and electrical features as compared to the existing mineral oil for power system equipment insulation. © 2015, Strojarski Facultet. All rights reserved.

In electrical power system, variety of solid, liquid and gaseous materials are used for insulation target to protect the incipient failure inside the high voltage power transformers. The insulation is practically ended when the insulation system has become fragile enough to flourish cracks under the electrical and mechanical stresses to which it is subjected. The electrical and mechanical stresses are induced by short circuit currents, thermal expansion and contraction of the conductors and vibration. The dielectric strength of insulation is not vitally diminished by brittleness alone, but electrical breakdown will rapidly follow the improvement of ensuing cracks. The purpose of this paper is to briefly cover the methods favourable for determining the insulating value of the insulation on high voltage power transformer windings and bushings. Many failures of insulation are caused by the entrance of moisture. Insulating materials used on high voltage power transformer windings have a high affinity for moisture from the surrounding atmosphere or oil. Effects of the stressed oil volume and stressing time on the breakdown stress of high voltage power transformer insulation were experimentally investigated. The factors influencing the effects and the results obtained based on them were statistically analysed and systematized by the Weibull distribution method. A Four-dimensional volume theory allowing good estimation of breakdown stress in terms of specific probable values has been established.

Pamuk N.,Turkish Electricity Transmission Company | Uyaroglu Y.,Sakarya University
Przeglad Elektrotechniczny | Year: 2012

A rapid and correct fault diagnosis is crucial for power system network. As the complexity of power system increases, fault diagnosis becomes very difficult task in the limited short time. This situation has made it necessary to develop intelligent systems to support operators in their decision making process. The paper mainly investigates fault diagnosis of power system by using Fuzzy Petri Nets (FPN) technology. FPN is used for accurately fault diagnosis in power system when some incomplete and uncertain alarm information of protective relays. It is shown from several cases that the faulted system elements can be diagnosed correctly by use of these models. By suggested method, it is possible to decline diagnosis time according to traditional methods. Finally, the suggested method can easily be adapted to different power system network. It is practicable an impressive for fault diagnosis in power system.

Pamuk N.,Turkish Electricity Transmission Company | Uyaroglu Y.,Sakarya University
Scientific Research and Essays | Year: 2011

In this study, thereby explaining under which circumstances an interconnected transmission network works that, in Turkey 380 and 154 kV power transmission lines connected to each other and consist of 18 generation and 96 load buses that the interconnected power network of Northwest Anatolia taken up with 114 buses and also done the power flow and constraint analysis in order to plan for new establishing systems. With these analysis, the loading of generation power plants was enabled in the most proper way. At Northwest Anatolia network; power flow analysis is done for different load conditions thereby using PSAT programme which is generated by Matlab, plants are determined which will be finished in 2010, proper generation planning is prepared according to high and normal load estimations and also all new rates are found out at buses. Newton-Raphson iteration method is used in PSAT programme. Supplement tranformers, transmission lines and power generation units are determined according to obtained analysis results. ©2011 Academic Journals.

Pamuk N.,Turkish Electricity Transmission Company | Uyaroglu Y.,Sakarya University
Elektronika ir Elektrotechnika | Year: 2012

In this paper, an approach of power system fault diagnosis model based on Petri Net (PN) is proposed. The construction of diagnosis model and the method of identifying the faulted components are described in detail. The detailed PN models and relevant conclude process are presented. The proposed system can spot the fault components fast and exactly, and constitutes reliable and impressive diagnosis results automatically. It can be applied in the power system for not only simple fault, but also multiple faults or the violent faults are made up of the protective devices false operation. This system is good for the fault diagnosis of power system. It shows that the fault diagnosis system based on the proposed models is practicable and impressive.

Pamuk K.,Turkish Electricity Transmission Company
Journal of Optoelectronics and Advanced Materials | Year: 2014

Electric power systems include a large number of expensive and crucial power cable systems over many decades. Every power cable is composed of at least two components; an electrical conductor, and the conductor insulation which prevents direct contact or unsafe proximity between conductor and other objects. The need to provide adequate electrical insulation which will also permit heat to be conducted and dissipated poses technical challenges at higher voltages. The insulation systems of high-voltage power cables and their accessories are subject to different kinds of stresses during their service life and thus suffer degradation and deterioration. The insulation materials of the high voltage cross-linked polyethylene power cables (XLPE) will be placed under high electrical stress caused by switching impulse. These high voltage switching impulse have an important effect on the aging of the insulation materials. These can lead to a reduction of life which in turn can lower the reliability of electrical power systems. This paper presents deterioration of XLPE-insulation will change insulation material properties and it should be possible to detect these changes with electrical analysis. These changes can lower the voltage withstand level of XLPE cables. Methods such as measurement of partial discharge parameters, and alternative current breakdown voltages analysis were used to determine the degree of deterioration.

Pamuk N.,Turkish Electricity Transmission Company
Journal of Optoelectronics and Advanced Materials | Year: 2014

Power transformer is one of the most expensive and strategically significant components of any power system, so that they are crucial parts of high voltage energy generation and transmission systems. Therefore their function is essential to power system reliability. This paper presents the life and long term degradation of oil impregnated cellulosic insulating materials used in power transformers. The purpose of this paper, changes of mechanical and dielectric strength of cellulosic insulating materials was examined by accelerated aging experiment for one year. Then, cellulosic insulating materials used in large capacity power transformers which had been operated for several years and up to 20 years were investigated. One of the results derived from the above examination and investigation is such that the mechanical characteristics of cellulosic insulating materials have been degraded down to approximately 50 percent of the initial value through operating for 20 years whereas electrical characteristics are less degraded.

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