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Abdel Aleem S.H.E.,15th of May Higher Institute of Engineering | Balci M.E.,Balikesir University | Sakar S.,Gediz University
International Journal of Electrical Power and Energy Systems | Year: 2015

In the literature, it is well known that transformers and cables have excessive losses or overheating under non-sinusoidal current conditions. Accordingly, they have reduced current carrying capabilities (or loading capabilities) for that kind of conditions. This paper aims to employ passive filters for the effective utilization of the cables and transformers in the non-sinusoidal systems. Consequently, an optimal passive filter design approach is provided to maximize the power factor expression, which takes into account frequency-dependent line losses, under non-sinusoidal background voltage and line current conditions. The individual and total harmonic distortion limits placed in IEEE standard 519 are taken into account as constraints for the proposed approach. Besides, keeping the load's displacement power factor at an adequate range is desired by the proposed approach. The proposed approach and the traditional optimal passive filter design approach, which aims to maximize the classical power factor expression, are comparatively evaluated for an industrial power system with a group of linear and non-linear loads, overhead transmission lines, cables and a transformer. Numerical results show that the proposed one has a considerable advantage in the improvement of the total supply line loss and the transformer's loading capability under non-sinusoidal conditions when compared to the traditional one. On the other hand, for the simulated system cases, both approaches lead to almost the same current carrying capability value of the cables. © 2015 Elsevier Ltd. All rights reserved.


Mousa A.G.E.,Cairo University | Abdel Aleem S.H.E.,15th of May Higher Institute of Engineering | Ibrahim A.M.,Cairo University
International Review of Electrical Engineering | Year: 2016

Any photovoltaic solar generator (PVSG) can be effectively utilized if it operates at its optimal operating point. Accordingly, many tracking algorithms for maximum power point tracking (MPPT) of photovoltaic (PV) modules had been developed. In the literature, the Perturbation and Observation (P&O) method and the Incremental Conductance (IC) method are the most widely used. Each of them has its unique advantages and disadvantages. In this paper, a maximum power point tracking algorithm method based on the analysis of the mathematical relationship among the maximum power points and the corresponding currents at different operating conditions, is presented. Several simulation results are provided to highlight the performance, effectiveness, advantages and disadvantages of the presented method compared to the conventional P&O and IC methods. Besides, a solar powered water pumping system is presented and discussed as an application of the different given MPPT techniques. © 2016 Praise Worthy Prize S.r.l. - All rights reserved.


Saeed A.M.,Cairo University | Abdel Aleem S.H.E.,15th of May Higher Institute of Engineering | Ibrahim A.M.,Cairo University | El-Zahab E.E.A.,Cairo University
International Review of Automatic Control | Year: 2014

Power quality is a very important topic of the recent power system network topics. It refers to maintaining a sinusoidal waveform of bus voltages. Unfortunately, the power system faces many disturbances which affect the supply waveform, such as under voltage, notching, harmonics, sag and swell voltages. In practice, sag voltage and harmonics are the major problems which can cause malfunctioning or tripping of equipment and many other problems on the system. One of the causes of these events is the inrush current during the energization of no-load transformers. This paper presents an effective and economic solution for the protection of sensitive loads from sags and harmonics using the dynamic voltage restorer (DVR). It also highlights the full functions of the DVR, showing that it can be considered as a proper solution to overcome the inrush current effects. Sag indices concepts on the distribution system are also presented, showing the performance of the DVR to get better results. The increasing of the DVR effectiveness as well as its simplicity and low cost are reasons for considering it as the best solution for many quality disturbances. Simulation results using MATLAB/SIMULINK are presented to verify the effectiveness of the proposed scheme. © 2014 Praise Worthy Prize S.r.l. - All rights reserved.


Aleem S.H.E.A.,15th of May Higher Institute of Engineering | Balci M.E.,Balikesir University | Zobaa A.F.,Brunel University | Sakar S.,Gediz University
Proceedings of International Conference on Harmonics and Quality of Power, ICHQP | Year: 2014

Transformers and cables have overheating and reduced loading capabilities under non-sinusoidal conditions due to the fact that their losses increases with not only rms value but also frequency of the load current. In this paper, it is aimed to employ passive filters for effective utilization of the cables and transformers in the harmonically contaminated power systems. To attain this goal, an optimal passive filter design approach is provided to maximize the power factor definition, which takes into account frequency-dependent losses of the power transmission and distribution equipment, under non-sinusoidal conditions. The obtained simulation results show that the proposed approach has a considerable advantage on the reduction of the total transmission loss and the transformer loading capability under non-sinusoidal conditions when compared to the traditional optimal filter design approach, which aims to maximize classical power factor definition. On the other hand, for the simulated system cases, both approaches lead to almost the same current carrying (or loading) capability value of the cables. © 2014 IEEE.


Balci M.E.,Balikesir University | Abdel Aleem S.H.E.,15th of May Higher Institute of Engineering | Zobaa A.F.,Brunel University | Sakar S.,Gediz University
Recent Advances in Electrical and Electronic Engineering | Year: 2014

In non-sinusoidal and unbalanced systems, optimal sizing of the capacitor banks is not a straightforward task as in sinusoidal and balanced systems. In this paper, by means of qualitative and quantitative analysis, it is interpreted that the classical capacitor selection algorithm widely implemented in Reactive Power Control (RPC) relays does not achieve optimal power factor improvement in non-sinusoidal and unbalanced systems. Accordingly, a computationally efficient algorithm is proposed to find the optimal capacitor bank for smart RPC relays. It is further shown in a simulated unbalanced and non-sinusoidal test case by using Matlab software that the proposed algorithm provides better power factor improvement when compared with the classical algorithm. It is also figured out from the simulation results that both algorithms cause almost the same harmonic distortion and unbalance deterioration levels in the system. © 2014 Bentham Science Publishers.

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