Person: POYRAZOĞLU, Göktürk
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POYRAZOĞLU
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Conference paperPublication Metadata only Digital data integration project between a DSO and a university for sustainability and efficiency(IEEE, 2022) Kartcı, Emin; Akkus, E. E.; Sancar, Semanur; Bugdayci, T. A.; Bektas, M.; Poyrazoğlu, Göktürk; Electrical & Electronics Engineering; POYRAZOĞLU, Göktürk; Kartcı, Emin; Sancar, SemanurDigitization in the energy sector enables big data analysis that can lead to large-scale energy efficiency due to the size of the sector and thus getting closer to sustainability targets. With a digital data integration study between a distribution company and a university in Turkey for big data processing, the data collected by IoT devices from 6,000 active transformers providing service in 5 cities were transferred to different servers together with the developed communication protocols. As a result of the project, the transformer efficiency and sustainability measures were produced. In this study, the mutually established software infrastructure and the benefits of the project are explained.Conference paperPublication Metadata only Safety test setup installation for e-bike battery systems(IEEE, 2022) Savrum, Mert; Poyrazoğlu, Göktürk; Electrical & Electronics Engineering; POYRAZOĞLU, Göktürk; Savrum, MertRecently, battery project studies have been increasing worldwide. Companies carrying out these projects must have their products checked for design safety and must obtain test approval reports in order to release their products on the market. IEC 62133-2 test approvals are required for lithium-ion rechargeable batteries, and EN 50604 test approvals are necessary for rechargeable li-ion batteries used in Light EV (electric vehicles). In addition, UN38.3(IEC 62281) battery transport tests must be applied for the transport of these batteries. These tests should be performed in an accredited laboratory, the safety of the design should be verified in this way, and then an accredited report should be issued to the product. There was no accredited laboratory in Turkey that performed tests in accordance with these standards. For this reason, companies were receiving services from overseas laboratories for the cell and battery approvals that they designed. There could be time and financial problems in overseas laboratories approvals. Due to these problems, an accredited laboratory was established at Vestel Electronics in Turkey, where tests can be carried out in accordance with IEC62133-2, EN50604, and UN38.3 (IEC62281) standards. Since batteries contain BMS cards, their tests are also carried out in this laboratory. Within the scope of this accredited laboratory established in Turkey, it will be stated how the test setups that meet the test requirements are set up. Test results with these devices will be evaluated. The test results will belong to an E-bike battery project.Conference paperPublication Metadata only Induction motor simulink implementation of the rotor flux oriented direct vector control method for electric vehicles(IEEE, 2021) Demircioğlu, İlayda; Poyrazoğlu, Göktürk; Electrical & Electronics Engineering; POYRAZOĞLU, Göktürk; Demircioğlu, İlaydaThis study aims to perform mathematical modeling of asynchronous motor and simulation of the rotor flux-oriented vector control method on a user-friendly platform. Besides, the obtained model is created as a PhiSim library, a product of Sherpa Engineering. This library was created using the bond-graph theory. Asynchronous motor is a good choice for electric vehicles due to its simple structure, low cost, high efficiency, robustness, high reliability, ability to work in bad environmental conditions, good dynamic performance, and wide speed range. The outputs from this study will serve the automotive industry. his simulation tool will be beneficial in investment decision-making processes and research.Conference paperPublication Metadata only Experimental impact analysis of the refrigerator cable design on disturbance power test(IEEE, 2022) Araz, Fırat; Poyrazoğlu, Göktürk; Electrical & Electronics Engineering; POYRAZOĞLU, Göktürk; Araz, FıratThe ever-increasing variety of electronic products brings with it many tests and controls. Especially for a product such as a refrigerator, which has an important place in the lives of users and works non-stop for almost its entire life, all compatibility tests that may affect the end-user must be carried out. Electromagnetic compatibility (EMC) tests are the most critical of these tests. In this study, the effect of the disturbance power test, one of the EMC tests, on the changing properties of the product was investigated. The effect of three different cable structures used in the refrigerator on the disturbance power test was investigated. These tests are carried out to cover 10 different frequencies in three products using different cable structures. Tables containing the oscilloscope results of these tests and the margin values corresponding to the frequencies are included in the document. In addition, visuals containing the differences between each cable structure and cable have been added. The results and analyzes of these tests are included in the report.Conference paperPublication Metadata only A stochastic simulation for a hybrid system of solar panels and EV chargers(IEEE, 2020-10-20) Hasdemir, Berke Can; Açıkgöz, Dilber; Poyrazoğlu, Göktürk; Electrical & Electronics Engineering; POYRAZOĞLU, Göktürk; Hasdemir, Berke Can; Açıkgöz, DilberIn line with the increasing number of electric vehicles, a stochastic approach that simulates the charging stations which is managed hybridlike system of a solar array is discussed in this study. A smart charging system algorithm is designed to control the charging status of electric vehicles arriving at a parking lot with a certain vehicle capacity based on the real data. Since charging electric vehicles can become an extra burden on the power grid, a smart charging algorithm is needed for stability and security. By solar energy, electric vehicles can be charged, and the surplus can be injected back to the grid. Otherwise, electricity can be provided from the grid. A stochastic-based simulation is developed to generate the necessary big-data based on realistic assumptions. The installation parameters of the solar energy, the number of vehicles in the parking lot, the hours of arrival, the duration of stay, and the charging status are simulated in various scenarios. This research aims to meet the demand for the increasing number of electric vehicles with the smart charging algorithm in the areas where have high solar energy potential.Conference paperPublication Metadata only Design of the circuitry, battery management system, and wireless communication of an electric vehicle(IEEE, 2019-06) Kurt, Atakan; Dolu, Uğur; Kaya, Burak; Poyrazoğlu, Göktürk; Electrical & Electronics Engineering; POYRAZOĞLU, Göktürk; Kurt, Atakan; Dolu, Uğur; Kaya, BurakElectric vehicles start to take an essential place in our lives to support the sustainability and energy efficiency. In order to train the required workforce, a team of engineering students is assigned to develop an in-house electric vehicle in a university in Turkey. The resultant electric vehicle participates in an electric vehicle efficiency challenge to compete against other teams. This study summarizes the details of two important components of an electric vehicle, the battery management system and wireless communication. The study also covers the complete circuitry of the designed vehicle for the hope to help the interested audience to demonstrate a high quality work on vehicle design.Conference paperPublication Metadata only Prediction algorithm & learner selection for European day-ahead electricity prices(IEEE, 2020-10) Ülgen, Toygar; El Sayed, Ahmad; Poyrazoğlu, Göktürk; Electrical & Electronics Engineering; POYRAZOĞLU, Göktürk; Ülgen, Toygar; El Sayed, AhmadThe prediction of day-ahead electricity prices with higher accuracy is always helpful for the market players of the power exchange. This study was intended in the first place to find out the best time series prediction method for the selected 14 European countries. The test results of four time-series methods show that the next day prices were more in line with the previous day prices in 87% of the selected countries; Later, a classification approach is followed by 33 different features of each country to answer the question of which method would be the best for the other countries, that were not studied in this paper, would be? As a result, the support vector machine algorithm results in 57% accuracy in classifying an unknown European country to determine the best prediction method. Therefore, this paper focuses now on two correlated studies to find out the best time series prediction methods and a classification approach for selected countries.ArticlePublication Open Access Determination of price zones during transition from uniform to zonal electricity market: A case study for Turkey(MDPI AG, 2021-02) Poyrazoğlu, Göktürk; Electrical & Electronics Engineering; POYRAZOĞLU, GöktürkIn the electricity market, different pricing models can be applied to increase market competitiveness. Different electricity systems use different market structures. Uniform marginal pricing, zonal marginal pricing, and nodal marginal pricing methods are commonly used market structures. For markets wishing to move from a uniform pricing structure to a more competitive zonal pricing structure, the determination of price zones is critical for achieving a competitive market that generates accurate price signals. Three different pricing zone detection algorithms are analyzed in this paper including the k-means clustering and queen/rook spatially constraint clustering. Finally, the results of a case study for the Turkish electricity system are shared to compare each method.Conference paperPublication Metadata only Battery integrated off-grid DC fast charging: Optimised system design case for California(IEEE, 2021) Elibol, B.; Poyrazoğlu, Göktürk; Çalışkan, B. C.; Kaya, H.; Armağan, Ç.; Akınç, H. E.; Kaymaz, A.; Electrical & Electronics Engineering; POYRAZOĞLU, GöktürkGlobal acceptance and exploitation of electric vehicles (EV) is no doubt a fact. There are two major factors beneath this growth; 1. increasing battery capacity thus rising range and 2. availability of DC fast charging infrastructure. Whereas battery is a topic of chemistry, DC fast charging is significantly related to grid operations. When installed, DC fast-charging stations (above 50 kW), require grid upgrades such as new transformers, underground cabling, LV/HV equipment installations on site. This not only increases the overall cost of installation but also the time from permit applications to operation. This study proposes a novel off-grid DC fast-charging station (FCS) that is integrated with a li-ion battery and solar photovoltaic (PV) that overcomes permitting, grid upgrades, and heavy installation activities on site. The system has 140 kWh liion battery, 100 kW DC fast charging units. In this study, a linear optimization algorithm is developed to assess the installed PV capacity. It is assumed that PVs will be installed over a parking area to make use of vast open land. The modularity of the PV system is considered to achieve scalability. Finally, an in-depth economic analysis is presented comparing conventional grid-tied FCS to the proposed system.Conference paperPublication Metadata only Impact of cyber-security breach to price signals on power market: An experimental human simulation(IEEE, 2018) Poyrazoğlu, Göktürk; Oh, H. S.; Electrical & Electronics Engineering; POYRAZOĞLU, GöktürkThe market power is a term defined in power economics as a potential to make the electric power market volatile. A supplier having the market power has an opportunity to speculate on the market clearing price. Observance of the market power may be destructive for the system only if a supplier actually exercises its potential. Although there are several studies on the assessment of market power, there is no study showing the consequences if a supplier stealthy exercises its market power. In order to fill this gap in the literature, a multi-player electric market game is developed and a realistic market environment is simulated with the participation of engineering students. Mainly the cyber-security issue in conjunction with the market power is focused in this study. For a limited number of periods, price information is intentionally corrupted via cyber-attack to create a misbelief at the supplier side. The analysis of the results showed that if a participant is under the impression of possessing the market power regardless actual possession, he/she would try to exercise it to raise its profit, and as a result, market clearing price starts to fluctuate.