Browsing by Author "Kul, Seda"

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Citation - WoS: 6
Citation - Scopus: 7
Coreloss Estimation via Long Short-Term Memory Model (LSTM) of Dry-Type Transformer based on FEA
(Ieee, 2021) Kul, Seda; İskender, İres; Yildiz, Berat; Tamyurek, Bunyamin; Iskender, Ires; 133746; Elektrik-Elektronik Mühendisliği
Accurate estimation of losses is very important in transformer designs for energy systems. Therefore, in this study, a long short-term memory model (LSTM) was performed to predict the core loss of three-phase dry-type transformers based on Finite Element Analysis (FEA) analysis. Since, in ordinary multilayer networks, learning problems occur when the gradient value gets too small during backpropagation. LSTM, on the other hand, can store information better thanks to its extra layers that communicate. Thus, the learning process takes place more efficiently. The analysis and estimation processes were performed using a primary number of turns, excitation voltage, and three different cross-section area parameters. 486 data randomly selected from 506 data obtained by ANSYS/MAXWELL in the training of the LSTM model were used. The remaining 20 data were used in the testing process to measure system performance. The error obtained by the validation test is 0.15. It is very close to the simulated value, thus LSTM can be used as a reliable estimation method during the design stage.
Citation - WoS: 0
Citation - Scopus: 4
FEA Simulation of the Electromagnetic Effects on the Flux Distribution of the Joints in the Transformer Core Structure
(Ieee, 2018) Kul, Seda; İskender, İres; Iskender, Ires; Balci, Selami; 133746; Elektrik-Elektronik Mühendisliği
In the manufacturing of the transformer the occurrence of air gaps at the joints of the legs and yokes of the core lamination stacking of the transformers is inevitable. The air-gap in the core joints affects the magnetic flux density and the magnetic flux distribution in the core. The location, shape, length and number of air-gaps all are different from each other. The increase in air-gap of transformer core will increase the reluctance of the core causing a reduction in the total magnetic flux value. The effects of the air-gap in joints cannot be exactly analyzed mathematically. However, the electromagnetic modeling using the finite element method provides facility to simulate and analyze such a problem. In this study, the effects of air-gaps with different shapes and length in the transformer legs on the stray magnetic are compared with using Finite Element Analysis (FEA) software.