Browsing by Author "Yukselen, Emir"

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Citation - WoS: 0
Citation - Scopus: 1
Analysis of Lightning Impulse Effects on Three Winding Transformer Used in Solar System Based ANSYS Maxwell
(Ieee, 2022) Yukselen, Emir; İskender, İres; Iskender, Ires; 133746; Elektrik-Elektronik Mühendisliği
Transformers are in more critical applications in the renewable energy world and having a transformer fail in such a cyclical power station can be disastrous. Over voltage or voltage strike is the most important phenomena for the transformers. Thus, the evaluating and estimating the effects and stresses of these sudden high voltages is important during the transformers life time operation and design stage. Accordingly in this paper the electromagnetic field analyses of the lightning impulse on Photovoltaic (PV) transformer are investigated using ANSYS Maxwell software. The 3D and 2D model simulation of the PV transformer is carried out to determine the electric field and voltage distribution on critical regions which can cause breakdown on insulation material and damage transformer windings and affects transformer working. Afterwards according to the simulation result, the subjected transformer was designed considering the relative critical regions and performs the full wave lightning impulse test in factory area to verify the dielectric strength of the transformer. This study provides better understanding of the lightning impulse voltage effects with localization of the critical regions on the PV transformer and helps to improve the withstand capability of the transformer against the lightning impulse voltages during the design and production stage.
Citation - WoS: 1
Citation - Scopus: 3
CASE STUDY ON THERMAL OPTIMIZATION OF OIL IMMERSED TRANSFORMER USED IN SOLAR POWER PLANT BASED ON GENETIC ALGORITHM AND COMPUTATIONAL FLUID DYNAMICS
(Vinca inst Nuclear Sci, 2023) Yukselen, Emir; İskender, İres; Iskender, Ires; 133746; Elektrik-Elektronik Mühendisliği
Transformers are one of the most capital investments in the solar power generation. Their safe and stable operations in the electrical networks are important. The main failure factor of transformers is the high temperature generated by the losses during operation, which increases the probability of insulation damage that significantly affects the useful life of transformer. Considering the importance of oil temperature and its effects on the life of the transformer, a numerical method is developed in this paper to optimize the cooling system of the transformer. In this regard, genetic algorithm is used as an optimization method to minimize the total cost of the cooling system while maintaining the required thermal conditions of the transformer. A comprehensive parametric study is carried out among the effective cooling geometry parameters using 3-D electromagnetic and thermal models of the photovoltaic transformer to evaluate and analyze the temperature distribution. The accuracy and feasibility of the proposed method is established by comparing the numerical results with those obtained from the experimental test. The results of the proposed method are found to be in a good agreement with the experimental and simulation results.
Citation - WoS: 0
Citation - Scopus: 1
Unbalanced Operation in Transformers Used in PV Plants
(int Journal Renewable Energy Research, 2022) Yukselen, Emir; Iskender, Ires; 133746
energy has become the most preferred energy sources today due to its environmental and economic advantages. One of the renewable energies is solar energy, in which Photovoltaic (PV) cells are used to convert solar energy into electrical energy. In this respect, Solar Power Plant (SPP) is one of the popular renewable energy sources and the integration of such power sources into electricity grids has been increasing in recent years. Transformers are one of the largest capital investments in solar power generation and the way they work is different from transformers used in a substation. Therefore, failure of transformers has significant economic effects on electrical networks. The PV type transformer is powered by the inverter and needs to be customized to work with every system. Consequently, the safe operation and reliability of this type of transformer is critical to the sustainability of the electrical grid. Consequently, identifying the probability of failure as a preventative action for grid protection is critical and should be addressed to improve electrical system reliability. The main purpose of this study is to analyze the effects of the unbalanced operation of the inverter on the performance of the special type transformer used in the PV plant and to show how the inverter operation can affect the operation of the transformer.