Ahmed Samawi Alkhafaji
Babylon University

Published : 2 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 2 Documents
Search

Transmitting audio via fiber optics under nonlinear effects and optimized tuning parameters based on Co-simulation of matlab and optisystemTM Abdulrasul A. Al-Hayder; H. J. Abd; Ahmed Samawi Alkhafaji
International Journal of Electrical and Computer Engineering (IJECE) Vol 10, No 3: June 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1077.916 KB) | DOI: 10.11591/ijece.v10i3.pp3253-3260

Abstract

Limitations of conventional wires such as copper wires are causing dispersion and distortion of the message signal for long distances communication especially for the wide bandwidths. The ability of fiber optic to overcome this problem is making it a dominant transmission medium. Despite of this major positive attribute of optic fibers, there is still a downside for using the fiber optic communication; that is the nonlinearity problem especially at the very high frequency bandwidth. For the first time, a desigen of an audio signal is suggested and executed in MatLab with an integration with OptiSystemTM software to discuss and solve this issu. The audio signal is then transmitted in different shapes of modulation signals (NRZ, RZ & RC) for different distances (100 km & 75 km) via a fiber optic media to be received in a receiving part of the simulated system. Three tests are used to do so. The first is the Quality-factor (Q-Factor) against the received power, second test is eye diagram performance and finally is the measuring of the amplitude of output (received) signal for each modulation signal shape using the Oscilloscope Visualizer. The NZR modulation signal was found to be the best one of the three used signals’ types in all three tests. The Q-factor for NRZ pulse shape (=12) was higher than that for RZ (=10) and RC (=8) for a 100 km distance at the same received power level.
The influence of iron losses on selecting the minimum excitation capacitance for self-excited induction generator (SEIG) with wind turbine Hayder Hussein Kadhum; Ahmed Samawi Alkhafaji; Hayder H.Emawi H. Emawi
Indonesian Journal of Electrical Engineering and Computer Science Vol 19, No 1: July 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v19.i1.pp11-22

Abstract

The capacitance selection of the three-phase self-excited induction generators (SEIG) driven by wind energy is influences by the iron losses. This paper is dealing with this problem by constructing a steady state model of the generator supplying an induction oil pump. No previous literature studying the requirements of selecting the minimum excitation capacitance under the iron loss impact is found. This work is focusing on: (i) a novel evaluation of the characteristics of the induction generator taking iron loss into account. (ii) the errors caused by neglecting the iron loss. (iii) the importance of including the iron-loss in any accurate analysis. (iv) the errors occurred in the selection of the precise excitation capacitance (Cexct) when the iron-loss neglected. Nodal analysis is suggested to describe the study-state performance of the proposed model. A Matlab/simulation is established to validate the proposed model.