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Physical Sciences and Mathematics Commons™
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Full-Text Articles in Physical Sciences and Mathematics
Temporal Preconditioners For Marching-On-In-Time-Based Time Domain Integral Equation Solvers, Hüseyi̇n Arda Ülkü
Temporal Preconditioners For Marching-On-In-Time-Based Time Domain Integral Equation Solvers, Hüseyi̇n Arda Ülkü
Turkish Journal of Electrical Engineering and Computer Sciences
Temporal preconditioners to stabilize the marching-on-in-time (MOT)-based time domain integral equation (TDIE) solvers are proposed. Exponentially decaying functions are used as temporal preconditioners and the proposed scheme is applied to analyze scattering from perfect electrically conducting objects using the second-order formulation. The effectiveness of the proposed scheme is demonstrated via numerical examples. It is shown that the temporal preconditioners stabilize the MOT system and the solution. In addition, the initial condition problem of TDIEs is investigated by extending the second-order formulation of the time domain electric field integral equation to the time domain magnetic and combined field integral equations.
Finite Element Modeling Of A Superconducting Fault Current Limiter, Lale Ergene, J. Keith Nelson, Raghunath Parthasarathi
Finite Element Modeling Of A Superconducting Fault Current Limiter, Lale Ergene, J. Keith Nelson, Raghunath Parthasarathi
Turkish Journal of Electrical Engineering and Computer Sciences
This paper summarizes the work done to show finite element modeling results on a high temperature superconductor fault current limiter (FCL). The paper also gives the small mock-up design of the matrix FCL and its finite element model (FEM). It also discusses the limitations of the FEM and explains how the results from the FEM compare with the experimental data derived for the configuration. A 3-dimensional FEM has been used because of the structure of the real geometry, which does not show any plane or axisymmetric features.
A Novel Motor Speed Calculation Method Using Square Wave Speed Sensor Signals Via Fast Fourier Transform, Hayri̇ Arabaci, Osman Bi̇lgi̇n
A Novel Motor Speed Calculation Method Using Square Wave Speed Sensor Signals Via Fast Fourier Transform, Hayri̇ Arabaci, Osman Bi̇lgi̇n
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a novel motor speed measurement method and experimental results using the fast Fourier transform (FFT). Motor speed is obtained using the square wave output signal of a speed sensor. In the proposed method, the speed can be measured in a wide range, and transient speed changes can also be clearly observed. The experiments were conducted during start-up and in steady state. The sampled speed data were transformed to frequency spectrums using the FFT. The frequency, which corresponds to the maximum amplitude in the spectrum, was used to calculate the motor speed. The test results show that the …