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Single Phase Asymmetrical Cascaded MLI with Extreme Output Voltage Levels to Switch Ratio Mahrous Ahmed; Essam Hendawi; Mohamed K. Metwaly
International Journal of Power Electronics and Drive Systems (IJPEDS) Vol 9, No 2: June 2018
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (29.184 KB) | DOI: 10.11591/ijpeds.v9.i2.pp712-721

Abstract

This paper proposes an asymmetrical cascaded single phase H-bridge inverter. The proposed inverter consists of two modules with unequal and isolated dc sources. Each module is composed of dc source, conventional four switches H-bridge and single bidirectional switch. To increase the output voltage levels, the tertiary ratio, 1:3, between its two dc sources is adopted. Both the fundamental frequency and the multicarrier pulse width modulation (PWM) control schemes are employed to generate switches signals. By controlling the inverter modulation index, the proposed inverter can generate an output voltage having up to seventeen levels by using only two modules. The proposed topology has also the feature of modularity which means that it can be extended to any levels by adding new modules. The proposed topology is simulated using an inductive load and some selected simulation results have been provided to validate the proposed inverter.
Fractional order PID controller adaptation for PMSM drive using hybrid grey wolf optimization Yasser Ahmed; Ayman Hoballah; Essam Hendawi; Sattam Al Otaibi; Salah K. Elsayed; Nagy I. Elkalashy
International Journal of Power Electronics and Drive Systems (IJPEDS) Vol 12, No 2: June 2021
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijpeds.v12.i2.pp745-756

Abstract

In this paper, the closed loop speed controller parameters are optimized for the permanent magnet synchronous motor (PMSM) drive on the basis of the indirect field-oriented control (IFOC) technique. In this derive system under study, the speed and current controllers are implemented using the fractional order proportional, integral, and derivative (FOPID) controlling technique. FOPID is considered as efficient techniques for ripple minimization. The hybrid grey wolf optimizer (HGWO) is applied to obtain the optimal controllers in case of implementing conventional PID as well as FOPID controllers in the derive system. The optimal controller parameters tend to enhance the drive response as ripple content in speed and current, either during steady state time or transient time. The drive system is modeled and tested under various operating condition of load torque and speed. Finally, the performance for PID and FOPID are evaluated and compared within MATLAB/Simulink environment. The results attain the efficacy of the operating performance with the FOPID controller. The result shows a fast response and reduction of ripples in the torque and the current.
Risk assessment of power system transient instability incorporating renewable energy sources Ayman Hoballah; Salah Kamal EL-Sayed; Sattam Al Otaibi; Essam Hendawi; Nagy Elkalashy; Yasser Ahmed
International Journal of Electrical and Computer Engineering (IJECE) Vol 12, No 5: October 2022
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijece.v12i5.pp4649-4660

Abstract

Transient stability affected by renewable energy sources integration due to reductions of system inertia and uncertainties associated with the expected generation. The ability to manage relation between the available big data and transient stability assessment (TSA) enables fast and accurate monitoring of TSA to prepare the required actions for secure operation. This work aims to build a predictive model using Gaussian process regression for online TSA utilizing selected features. The critical fault clearing time (CCT) is used as TSA index. The selected features map the system dynamics to reduce the burden of data collection and the computation time. The required data were collected offline from power flow calculations at different operating conditions. Therefore, CCT was calculated using electromagnetic transientsimulation at each operating point by applying self-clearance three phase short circuit at prespecified locations. The features selection was implemented using the neighborhood component analysis, the Minimum Redundancy Maximum Relevance algorithm, and K-means clustering algorithm. The vulnerability of selected features tends to result great variation on the best features from the three methods. Hybrid collection of the best common features was used to enhance the TSA by refining the final selected features. The proposed model was investigated over 66-bus system.
A high performance grid connected PV system based on HERIC transformerless inverter Essam Hendawi
Indonesian Journal of Electrical Engineering and Computer Science Vol 20, No 2: November 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v20.i2.pp602-612

Abstract

This paper presents an effective single phase grid connected photovoltaic PV system based on High Efficiency and Reliable Inverter Concept HERIC transformerless inverter. Dc-dc boost converter controlled by incremental conductance IC maximum power point tracker MPPT is employed to achieve the maximum extraction power of the PV panels. Proportional integral PI controller controls the output voltage of the boost converter to meet the utility grid requirements. LCL filter is utilized to keep the inverter voltage very close to sinusoidal shape. Employing the HERIC transformerless inverter reduces significantly the ground leakage current beyond safe limits. Semiconductors losses are studied to investigate the efficiency of the proposed system at different insolation levels. Simulation results verify the high performance of the proposed system when considering leakage current and system efficiency.