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An Assessment on Aging Model of IEEE/IEC Standards for Natural and Mineral Oil-Immersed Transformer
(Ieee, 2011) Biçen, Yunus; Çilliyüz, Yusuf; Aras, Faruk; Ayduğan, Güzide
This paper presents an assessment on aging model of IEEE and IEC standards using thermal model of oil-immersed power transformer for natural ester and mineral oil. For this purpose, a model created for the analysis of behavior transient thermal performance with aging both of natural ester and mineral oils. Thermal model of the transformer is based on thermal-electrical analogy that is calculated separately for natural and mineral oils covering top-oil and hot-spot temperatures. The hot-spot temperature values of each ester/oil are used to calculate aging parameters which include the aging acceleration factor, time dependent relative aging rate and insulation life loss variations.
Current practices, potentials, challenges, future opportunities, environmental and economic assumptions for Türkiye's clean and sustainable energy policy: A comprehensive assessment
(Elsevier Ltd, 2023) Ağbulut, Ümit; Yıldız, Gökhan; Bakır, H.; Polat, Fikret; Biçen, Yunus; Ergün, Adem; Gürel, Ali Etem
In today's world, most countries including Türkiye have met their electricity demand at a dominant rate by burning fossil-based fuels in thermal power plants. However, fossil-fuel reserves have been rapidly depleted, resulting in high volatility in these fuels’ markets, as well as alarming environmental, and economic problems for the governments. In recent years, many governments have started to face these problems and have rapidly transitioned to renewable and alternative carbon-free energy sources in their electricity production variety. However, these belated steps have failed to mitigate the increment in global greenhouse gas emissions against the rapid growth of population and energy demand. In recent years, Türkiye has put a noteworthy challenge to mitigate its dominant use of fossil fuels, reducing its energy dependence, sustaining its economic development, and mitigating the carbon footprint. From this point of view, it is witnessed that many power plants have been established, many of them are currently under construction, especially to produce more electricity in a sustainable way. Accordingly, the present study aims to comprehensively discuss Türkiye's energy production policy, energy potential and reserves, challenges, future opportunities, and the impacts of the energy sector on the economic and environmental issues for the country. In this framework, it is well-noticed that the country's future energy production policy has been reasonably changed in order to achieve positive economic and environmental outcomes in the medium and long term. © 2023 Elsevier Ltd
Development of IoT Based Battery Management System
(Ieee, 2021) Çeven, Süleyman; Küçükkülahli, Enver; Albayrak, Ahmet; Biçen, Yunus
In this study, the modular battery management system used in electric vehicles was developed and monitored with the IoT-based MQTT protocol. In recent years, electric vehicles have been widely studied by researchers and long-lasting battery systems have been developed. In this study, a modular battery management system that performs the charging process with the passive balancing method has been developed. The battery has been developed for electric vehicles with more than 1 kWh of energy. There is temperature, current and voltage sensors at each node for battery management. A temperature sensor has been added to the system in case of overheating of the battery. The data collected over the battery is transferred to the web environment with MQTT, one of the IoT protocols. Passive balancing is preferred for balancing the batteries during charging. During charging, the MQTT server notifies the network to set the required voltage for each node.
Fuzzy logic-based user interface design for risk assessment considering human factor: A case study for high-voltage cell
(Elsevier, 2014) Aras, Faruk; Karakaş, Ercüment; Biçen, Yunus
This paper presents a novel risk assessment model considering human factor based on the fuzzy logic approach. For the contribution of the literature, not only the number of people is included in the process of risk assessment, but also with the human factor as a quantitative entry in this study. A flexible and user-friendly risk assessment interface is developed using LabVIEW program, which puts at disposal different applications for the course material. Designed interface gives an opportunity to users to assess risks in a wide range of consequences containing many different combinations and options. The interface is tested for a 100-kV high-voltage cell as a case study. As a result, it is seen that the interface assesses plenty of input elements and possibilities in a short time. For this reason, the fuzzy logic approach is suggested as a suitable method for risk assessment. (C) 2014 Elsevier Ltd. All rights reserved.
Fuzzy tuning approach for adaptive exponential smoothing used in short-term forecasts
(Pamukkale Univ, 2017) Biçen, Yunus
Adaptive smoothing methods were suggested to improve forecast results on the characteristic changes of time series. The existing adaptive smoothing methods have been diversified over the years. Many of them are comprised of complicated logical or mathematical propositions for improving forecast accuracy, which are very different from the original simple method called Trigg and Leach method. A new method named Fuzzy Tuning Exponential Smoothing is introduced in this paper introduces. This method is successful in improving the forecast accuracy, especially for the time series including level shift or level shift with outlier deflection. The empirical application carried out on 'The M2-Competition Time Series'. The statistical analysis results demonstrate that the method outperforms classical adaptive smoothing method in terms of forecasting accuracy. In addition, the proposed method is relatively simple compared to other advanced adaptive methods.
Intelligent Condition Monitoring Platform Combined with Multi-agent Approach for Complex Systems
(Ieee, 2014) Biçen, Yunus; Aras, Faruk
Condition monitoring and data analysis are key factors to avoid unexpected catastrophic breakdowns and detect incipient failures. Managing of these processes are not easy in complex system which has many inputs/outputs and interdependent relationships. In conventional methods, the condition monitoring is carried out separately and systematically due to the large number of monitoring point. This paper presents an intelligent condition monitoring platform (ICMP). This platform uses multi-agent system (MAS) advantages via mathematical process named failure sensitive matrix (FSM). Through this platform, the whole system is dynamically monitored, despite all the complexity. Cause and effect relations of a fault are evaluated more comprehensively and the success of achieving global results is higher. The growth of monitoring equipment or system is not a problem, because matrix structure is expandable as wanted and its performance is fast due to the nature of the parallel computation. Other important advantage of this platform is that it is an interface which works with expert systems and artificial intelligence techniques with no restrictions.
An Internet of Things (IoT) based Monitoring System for Oil-immersed Transformers
(2019) Yaman, Okan; Biçen, Yunus
While the electricity power industry in the world continues to grow, it also becomes more traceable and smart with the developing technology. Naturally, the integration of these technologies into the electrical power systems brings with an additional cost. Most of the time producers and consumers struggle under the pressure of these additional costs and try new products that will reduce the cost. In this sense, competitive products in the market must be advantageous in terms of cost. In this study, an original IoT based transformer monitoring system has been developed by using open source software, modular and low cost components as an alternative to studies in literature. Arduino Mega 2560 microcontroller has been used as the main component in the system. The system can acquire data from a wide variety of sensors using internal and external transducers. And this data can be saved to the cloud system synchronously with the memory card on the monitoring system. The developed monitoring system has been utilized free and reliable platforms such as the ThingSpeak web interface and PushingBox Notification application. The all test process of the developed monitoring system has been carried out in the laboratory environment on a porotype transformer.
İŞ GÜVENLİĞİ UZMANLARINI ETKİLEYEN FAKTÖRLERİN RİSK ANALİZİ VE DEĞERLENDİRME SÜREÇLERİ ÜZERİNDEKİ BAĞIL ETKİLERİNİN DEĞERLENDİRİLMESİ
(Turkish Science and Research Foundation (TÜBAV), 2018) Çıkmak, Sinan; Biçen, Yunus; Aras, Faruk
Türkiye’de iş sağlığı ve güvenliği algısını ve bu konuda yürütülen tüm çalışmaların niteliğini istenen seviyeye çıkarmak adına yapılan birçok düzenleme bulunmaktadır. İş sağlığı ve güvenliği konusunda son yıllardaki A, B ve C sınıfı uzmanlarının sayısının artması, ortak sağlık güvenlik birimlerinin birbiri ardına kurulması, yasal mevzuatların kamu ve özel sektör için uygulamaya sokulması sektörün dinamik bir yapıya kavuşmasını sağlamıştır. Ancak hızlı bir gelişim ve değişim gösteren her alanda olduğu gibi, iş sağlığı ve güvenliği alanında da bazı sorunların ortaya çıkması kaçınılmazdır. İş güvenliği profesyonellerini ve sorunlarını konu alan çalışmalara literatürde rastlanmasına karşın, kişisel ve çevresel bileşenlerin yapılan iş sağlığı ve güvenliği çalışmalarını hangi oranda etkilediğine dair yeterli bilimsel çalışmalar bulunmamaktadır. Bu çalışmada iş güvenliği uzmanlarının özellikle risk analizi ve değerlendirme süreçlerinde kişisel ve çevresel faktörlerden etkilenme düzeyleri araştırılmıştır. Bu kapsamda Türkiye'de aktif olarak çalışan A, B ve C sınıfı iş güvenliği uzmanlık belgesine sahip erkek ve kadınlar araştırmanın evreni kabul edilerek, kendilerine internet tabanlı anket yöntemi ile ulaşılmıştır. Anketin yanılma payı yaklaşık % 6 olup, elde edilen sonuçlar SPSS programı kullanılarak yorumlanmıştır.
Kısa dönemli tahminlerde kullanılan uyarlamalı üstel düzleştirme için bulanık ayarlama yaklaşımı
(2017) Biçen, Yunus
Uyarlamalı düzleştirme metotları zaman serilerinin karakteristik değişimleri üzerindeki tahmin sonuçlarını iyileştirmek için önerilmişlerdir. Zaman içerisinde var olan uyarlamalı düzleştirme metotları çeşitlenmiştir. Birçoğu Trigg & Leach olarak isimlendirilen orijinal basit metottan çok farklı olup, doğruluğu artırmak için karmaşık mantıksal veya matematiksel önermeler içermektedir. Bu makalede Bulanık Ayarlamalı Üstel Düzleştirme olarak isimlendirilen yeni bir metot sunulmaktadır. Bu metot özellikle seviye kayması veya seviye kaymasıyla beraber aykırı sapmaların bulunduğu zaman serileri için tahmin doğruluğunun iyileştirilmesinde başarılıdır. Ampirik uygulama 'The M2-Competition Time Series' üzerinde gerçekleştirilmiştir. İstatistiksel analiz sonuçları tahmin doğruluğu açısından bu metodun klasik uyarlamalı üstel düzleştirme metodunu geride bıraktığını göstermektedir. Buna ek olarak önerilen metot diğer gelişmiş uyarlanabilir metotlarla karşılaştırıldığında oldukça basittir.
Lifetime Estimation and Monitoring of Power Transformer Considering Annual Load Factors
(Ieee-Inst Electrical Electronics Engineers Inc, 2014) Biçen, Yunus; Aras, Faruk; Kırkıcı, Hülya
This paper focuses on the realistic remaining service life prediction and monitoring system of power transformers, using an algorithm developed by the authors. The power transformer is one of the vital components of power transmission and distribution substations. It is important to know the loading capacity and remaining service life of a power transformer to ensure its economical and secure operation. This information is directly related to the condition of cellulosic insulation. According to classical method of prediction, the power transformer is considered to be operated under constant load for the remainder of its lifespan. However, in reality the load factor varies continuously, and this is a key factor affecting the service life of power transformers. In this study, a realistic method for monitoring and predicting the service lifetime of power transformers is presented by considering annual load factors. The proposed method is applicable to any power transformer and can be updated by considering relevant standards for different liquid and solid insulation materials. As a case study, life-loss calculation and the remaining service life predictions are carried out using a thermal model that has been created considering a 250 MVA mineral oil-immersed power transformer.
Loadability of power transformer under regional climate conditions: the case of Turkey
(Springer, 2014) Biçen, Yunus; Aras, Faruk
This paper presents an accurate methodology and examines the effects of long-term ambient temperature changes on the power transformer loadability and its service life loss considering regional climate characteristics. The daily ambient temperature variation is modeled on yearly basis for different climate regions according to historical records. For this purpose, four different regions are selected in Turkey. Thermal and service life loss models are tested under two loading conditions for selected climate projections. Models used in the study, are created in accordance with IEEE C57.91-95 and IEC 60076-7 standards. Calculations are made in high resolution as the basis of second distinct from related standards, for mineral oil-immersed power transformer parameters. In this way, the impact of regional climate conditions on power transformer loadability is determined more accurately. The results show that the power transformer loadability is a function of the regional climate conditions. In addition, the result of the analysis, some coefficients are recommended for power transformer loadability to complete a normal service life range (20.55 years) under selected regional climate conditions. This methodology is applicable to the different climate regions and power transformers outside scope of this study.
Monitoring of Critical Substation Equipment
(Ieee, 2015) Biçen, Yunus
This paper presents lifetime monitoring algorithm available for critical substation equipment. In the remaining life calculation stage, two proposed methods named the weighted moving average - based monitoring and the trend adjusted (double) exponential smoothing - based monitoring introduced, respectively. Both methods are evaluated for various cases and the validity of the first methods tested on the prototype transformer, experimentally. However, the second newly method has advantages such as wide forecast range, trend determination capability and insensitive to short term fluctuations. These methods with the algorithms are applicable for the instrument or its parts that aging characteristics can be expressed by the empirical equations under certain stress/stresses.
Nanoparticles for next-generation transformer insulating fluids: A review
(Pergamon-Elsevier Science Ltd, 2022) Karataş, Mehmet; Biçen, Yunus
Transformers are important components in electrical networks and dielectric fluids play a decisive role in the quality of the insulation systems in these transformers. This review focuses on dielectric nanofluids, which in recent years have come to the fore as innovative electrical insulating fluids. In this context, all studies on insulating base fluids and nanoparticle types have discussed in depth the preparation and stabilization of dielectric nanofluids, their dielectric improvement, viscosity changes, thermal conductivity levels, dissipation factors, partial discharge phenomena, physicochemical properties, aging characteristics, and paper-nanofluid interactions. An average improvement of around 21% was found for the level of breakdown voltage as well as for the lightning impulse breakdown voltage. However, the average enhancement value for positive polarity was 20% for dielectric nanofluids, with an average value of around 10% for the increase in viscosity. Thermal conductivity is higher in nanofluids than in base insulating fluids, which somewhat compensates for the negative situation in viscosity, with the average enhancement in thermal conductivity at around 6%. In related studies, among the physicochemical properties of dielectric nanofluids, a remarkable increase (10% on average) was observed in the flash point level. Although not enough studies have been conducted on the interaction of nanofluids with the cellulosic insulation material used in transformers, pioneering experimental studies have given positive results, especially for aging issues. Dielectric nanofluids have many advantages over conventional insulating fluids, and the ongoing application challenges for future studies are also discussed in this review.
A Novel Gui Simulation Program Designed for Teaching of Underground Power Cables
(Ieee Computer Soc, 2009) Biçen, Yunus; Aras, Faruk
This paper presents a novel computer simulation program designed to aid teaching process in course of underground power cables for engineering students. The calculation of power cable ratings uses several different formulas and long analytical processes based on JEC 60287 and IEC 60853 standards. Therefore it is difficult to examine different variations such as power cable properties, installations and operation conditions, during the restrictive lesson time. For these reasons, a program has been developed to use for teaching process of the power cable course. The program allows the users to effectively learn the rating of underground power cables under different operation conditions with illustrative figures. The program details are presented and explained in this paper.
Propositional logic concept for fault diagnosis in complex systems
(Elsevier B.V., 2020) Biçen, Yunus
A great number of monitoring technologies have been developed especially for complex systems within the critical zones such as electric power substations, nuclear energy systems. But also, there is no single instruction or standardization in fault-focused on-line/off-line monitoring applications due to the acceleration of technological developments. Field experts have difficulty in choosing which test and measurement systems should be used in which stage of the complex systems. In this study, the propositional logic-based concept is presented, which field experts can use to manage this process. In this concept, test and measurement systems can be grouped according to the priority-order. According to the results of the graded groups on this concept, the suspected fault is verified by the cause of the occurrence. The applicability of the proposed concept has been tried to be explained by creating possible failure scenarios on the transformer. The theoretically validated concept can be used for even more fault situations. This concept can also be used in another complex systems with a large number of T&M systems where very different fault conditions can occur. 2009 Elsevier Ltd. All rights reserved. © 2020 Karabuk University
A realistic method for remaining service life prediction of power transformer
(Praise Worthy Prize S.r.l, 2013) Biçen, Yunus; Aras, Faruk; İsmailoğlu, Hasbi
In recent years, many studies have been done on monitoring, analyzing and aging performance of power transformer which is one of the most important components of power system. It is important to know the loading capacitance and remaining service life of a transformer to ensure its economical and secured operation. In this study, a realistic method is presented for remaining service life prediction and life-loss calculation of the power transformers. The proposed method is applicable for all the power transformers and can be updated in the light of the relevant standards for the different liquid and solid insulation materials. As a case study, life-loss calculation and the remaining service life prediction is carried out using thermal model that has been created considering the parameters of the 250 MVA mineral oil-immersed power transformer. © 2013 Praise Worthy Prize S.r.l. - All rights reserved.
A robust algorithm based on a failure-sensitive matrix for fault diagnosis of power systems: an application on power transformers
(Tubitak Scientific & Technical Research Council Turkey, 2015) Biçen, Yunus; Aras, Faruk
In this paper, a robust algorithm for fault diagnosis of power system equipment based on a failure-sensitive matrix (FSM) is presented. The FSM is a dynamic matrix structure updated by multiple measurements (online) and test results (offline) on the systems. The algorithm uses many different artificial intelligence and expert system methods for adaptively detecting the location of faults, emerging failures, and causes of failures. In this algorithm, all data obtained from the power transformer, which have various nonlinear input and output parameters, are processed using the parallel matrix structure of the FSM to reach a global solution quickly. The parameters of a power transformer are used to verify the algorithm under 4 operating conditions simulated in the MATLAB-Simulink program. The obtained results show that the algorithm is convenient for determining incipient failures of a system that consists of multiple parameters.
Steady State Effects of Design Properties and Environmental Conditions on Underground Power Cable Ampacity
(Ieee, 2017) Biçen, Yunus; Aras, Faruk
The steady state analysis of the cables under selected design and installation conditions provide information to ensure that the cables remain within allowable operating temperature limits. Manufacturers share the ampacity levels and derating factors under certain conditions for the cables that they produced, depending on the standards. However, the diversity of conditions can increase in the real applications. In this study, ampacity comparisons have been carried out for a different design and environmental characteristics of an underground cable system. The selected parameters have been analyzed for steady-state conditions within certain ranges. Characteristic ampacity trend curves corresponding to the relevant parameter changes have been generated with iterative solutions.
Thermal modelling and analysis of high-voltage insulated power cables under transient loads
(Wiley, 2013) Aras, Faruk; Biçen, Yunus
This article presents a simple thermal model for transient analysis of high-voltage underground power cables based on proper ladder diagram at MATLAB-Simulink software under various operating conditions for engineering students. Available commercial programs created with commercial worries are not suitable for students during the learning process, which involve different applications on power cable analysis. The model gives an opportunity for students to solve the often-faced transient problems in utilities. The transient model of the underground power cable system using the analytic procedures based on IEC60853 standards is presented with an example solution of the 154kV power cable in service in Turkish transmission system in this article. (c) 2010 Wiley Periodicals, Inc. Comput Appl Eng Educ 21: 516-529, 2013
Trend adjusted lifetime monitoring of underground power cable
(Elsevier Science Sa, 2017) Biçen, Yunus
Insulated power cables are the most critical devices used in electrical network for urban areas. Also, lifespan knowledge of these devices is the important information for decision-makers to make their investment planning. This study has presented a practical method for estimating the remaining lifetime of a power cable. The validation of the method has been tested under two different cases for 154kV XLPE insulated underground power cable system. Power cable thermal network has been modeled for a short-duration transient according to electrical analogy. Lifetime monitoring has been carried out by considering loss of life trend depending on the load raising an annual basis. The results show that the accuracy of the remaining service life estimation is related to receiving data with high sample-rate and determining loss of life trend curve belonging to the power cable. The realistic estimations are carried out using trend-adjusted exponential smoothing. (C) 2016 Elsevier B.V. All rights reserved.

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