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Your search keyword '"Dousoky, Gamal M."' showing total 99 results
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99 results on '"Dousoky, Gamal M."'

1. Prototype Implementation of a Digitizer for Earthquake Monitoring System.

Author

Helal, Emad B., Saad, Omar M., Soliman, M. Sami, Dousoky, Gamal M., Abdelazim, Ahmed, Samy, Lotfy, Kanaya, Haruichi, and Hafez, Ali G.

Subjects
GRAPHICAL user interfaces, GPS receivers, SEISMIC networks, IMPULSE response, EARTHQUAKES, DATA transmission systems
Abstract

A digitizer is considered one of the fundamental components of an earthquake monitoring system. In this paper, we design and implement a high accuracy seismic digitizer. The implemented digitizer consists of several blocks, i.e., the analog-to-digital converter (ADC), GPS receiver, and microprocessor. Three finite impulse response (FIR) filters are used to decimate the sampling rate of the input seismic data according to user needs. A graphical user interface (GUI) has been designed for enabling the user to monitor the seismic waveform in real time, and process and adjust the parameters of the acquisition unit. The system casing is designed to resist harsh conditions of the environment. The prototype can represent the three component sensors data in the standard MiniSEED format. The digitizer stream seismic data from the remote station to the main center is based on TCP/IP connection. This protocol ensures data transmission without any losses as long as the data still exist in the ring buffer. The prototype was calibrated by real field testing. The prototype digitizer is integrated with the Egyptian National Seismic Network (ENSN), where a commercial instrument is already installed. Case studies shows that, for the same event, the prototype station improves the solution of the ENSN by giving accurate timing and seismic event parameters. Field test results shows that the event arrival time and the amplitude are approximately the same between the prototype digitizer and the calibrated digitizer. Furthermore, the frequency contents are similar between the two digitizers. Therefore, the prototype digitizer captures the main seismic parameters accurately, irrespective of noise existence. [ABSTRACT FROM AUTHOR]

Published
2024
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20. Low-Harmonics Three-Phase Power Conditioner for hotovoltaic Integration

Author

El-tamaly, Hassan H., Dousoky, Gamal M., and Shoyama, Masahito

Subjects
Power conditioning unit, Harmonic filters, Pulse-width-modulation, Inverter, Power factor correction, Photovoltaic energy
Abstract

This paper describes the design of a power conditioning unit (PCU) for photovoltaic power system to be interconnected with the utility grid (UG). The proposed PCU employs six-pulse three-phase inverter with modified-sinusoidal-pulse- width-modulation (MSPWM) switching technique, a parallel and series filters and an efficient control of dc to ac power conversion. The parallel and series filters are designed for both harmonics reduction and power factor correction. The efficient control of dc to ac power conversion makes the inverter output voltage immune to the variation in the dc voltage. The proposed PCU has been studied with both equation solving and extensive simulations. A 5 MW PCU has been designed and its performance has been investigated in detail.

Published
2010

21. Triple-Hybrid Switching Strategy for Conducted-Noise Level Reduction in DC-DC Converters

Author

Dousoky, Gamal M., Shoyama, Masahito, and Ninomiya, Tamotsu

Subjects
Switched-mode power supply, Spread-spectrum, Noise reduction, EMC,EMI, Modulation strategy
Abstract

A novel switching strategy for conducted-noise level reduction has been proposed in this paper. The proposed strategy uses three randomized parameters for generating the switching signals. These parameters are carrier frequency, duty-ratio, and the pulse position. This triple-hybrid switching strategy has been designed and implemented using field-programmable gate array (FPGA) technology. Moreover, the effect of using the proposed controller on commonmode and differential-mode noise, total conducted-noise, and radiated-noise characteristics of the dc-dc converter has been experimentally investigated. Furthermore, sweeping of the three randomization parameters has been carried-out for identifying the values which achieve the best conducted-noise level reduction. Numerous cases have been studied. All the studied cases have been designed, implemented and experimentally investigated. Then, the conducted-noise spectra have been compared. The experimental results show that using the proposed technique, with the identified randomization parameter values, significantly improves the conducted-noise spectrum and effectively reduces the noise peaks in both high- and low-frequency ranges. Moreover, the radiated-noise spectrum has been improved.

Published
2010

38. New Design Approach for Grid-Current-Based Active Damping of LCL Filter Resonance in Grid-Connected Converters.

Author

Gaafar, Mahmoud A., Dousoky, Gamal M., Ahmed, Emad M., Masahito Shoyama, and Orabi, Mohamed

Subjects
*HIGHPASS electric filters, *ELECTRIC current regulators, *DAMPING (Mechanics), *RESONANCE, *ROBUST control
Abstract

This paper investigates the active damping of grid-connected LCL filter resonance using high-pass filter (HPF) of the grid current. An expression for such HPF is derived in terms of the filter components. This expression facilitates a general study of the actively damped filter behavior in the discrete time domain. Limits for the HPF parameters are derived to avoid the excitation of unstable open loop poles since such excitation can reduce both the damping performance and the system robustness. Based on this study, straightforward co-design steps for the active damping loop along with the fundamental current regulator are proposed. A numerical example along with simulation and experimental results are presented to verify the theoretical analyses. [ABSTRACT FROM AUTHOR]

Published
2018
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