Abou-Hashema M. El-Sayed

A proposed strategy for capacitor allocation in radial distribution feeders

A new strategy for capacitor allocation in radial distribution systems is presented in this paper. This strategy adds a new constraint to the well-known constraint (allowed voltage violation). The new constraint is the sectional ohmic loss in each branch of the feeder. Sizes and locations of the capacitors are selected in order to achieve the maximum reduction in the total losses in the system. Sometimes this reduction is not achieved in all the branches but the loss in any individual branch of the system is not allowed to increase than it was before the capacitor placement. The proposed strategy is applied to two different distribution systems with 9 and 34-buses respectively. The results of the proposed strategy are compared with previous works. The comparison showed the validity and the superiority of this strategy.

Grid Synchronization Enhancement of a Wind Driven DFIG Using Adaptive Sliding Mode Control

Besides power decoupled control, soft and fast synchronization is an important issue because it enables the DFIG to be connected to the grid with minimum impact on the WECS and the grid [135].

Improved Orientation Strategy for Energy-Efficiency in Photovoltaic Panels

This paper presents an improved orientation strategy for energy-efficiency in photovoltaic (PV) panels. Conventionally, PV panels are tilted with the site’s latitude angle or the difference between the latitude angle and the solar declination angle. A monthly-based orientation strategy has been proposed and analyzed in this study. The proposed strategy implies that the PV panels are tilted with the monthly-based angle that achieves the maximum incident radiation. Furthermore, the impact of using the proposed orientation strategy and three conventional strategies on the produced power and on the PV system design features has been investigated in detail. A Japanese city (Fukuoka) and an Egyptian city (Al-Kharijah) have been considered as locations for the PV power system installation. The results showed that the proposed strategy achieved an increase in the power produced from the PV power systems at the two different sites, and consequently the required solar cells area can be saved. Therefore, the cost of the PV power system components can be reduced including the solar cells area and the land area.

A Modified MRAS Observer for Sensorless Control of a Wind Driven DFIG Connected to Grid

The Doubly Fed induction generator (DFIG) is a popular wind turbine system due to its high energy efficiency, reduced mechanical stress on the wind turbine, and relatively low power rating of the connected power electronics converter of low costs [126].

Conclusions and Suggestions for Future Work

In view of the analysis and investigations presented, one can draw the following main conclusions: The phase angle between grid voltage and current waveforms is changed from leading to lagging within one cycle for step change in reactive component of grid current reference \( i_{\text{gq}}^{*} \). This confirms that, the capability of the GSC control to regulate the grid received reactive power for controlling the system power factor.

Adaptive Sliding Mode Control for Grid Synchronization of a Wind Driven DFIG Under Unbalanced Grid Voltage

However, wind energy conversion system (WECS) is usually located in rural areas with weak grid connection, in which grid voltage unbalance may arise even during normal operation. The unbalanced grid voltage may be caused by unbalanced transmission line impedance, three-phase unbalanced load, and single-phase high-power load. Hence, the strategies to improve the performance of DFIGs under unbalanced network conditions have obtained a worldwide concern.

Mathematical modeling of Photovoltaic module and evalute the effect of varoius paramenters on its performance

A detailed models of Photovoltaic PV module of both single and double diode model is presented in this paper. The presented photovoltaic module electrical models are related to Shockley diode modules. These models consider the solar radiance and temperature as input parameters. A Comparative study of several models is performed for a wide range of different parameters. The influence of several variables on both single and double diode models have been illustrated. KC200GT-200W module data sheet has been used in this study for the simulation. The achieved o.c. voltage and s.c. current values from I–V and P-V characteristics are compared with module data sheet. The Matlab Software is used for solving all system equations.