This paper presents design and performance of high power quality single-phase grid inverter that fed from photovoltaic (PV) system through maximum power tracker for residential application. The ...proposed designed inverter is based on sinusoidal pulse width modulation (SPWM) technique in combination with series-resonance and high-pass filters at low side of inverter. The filters and SPWM are designed to reduce the total harmonic distortion (THD) to limit values that coincide with IEEE and IEC standard recommendations without harmonic resonance. The proposed inverter is equipped with synchronizing system with the utility grid at 220V and 50Hz. The synchronizing system of embedded Matlab software is based on phase locked loop (PLL), adjustable phase shift leading angle of inverter, and root mean square (RMS) of grid and inverter voltages philosophies to satisfy synchronization requirements. The performance of the proposed inverter is investigated through Matlab/Simulink simulations. The simulation results using Matlab/Simulink show good quality performance for 80W PV solar module. The results are excellent and the proposed inverter PV system is suited for practical applications of Egyptian consumers with utility grid.
Treatment of EMF on the protection IEDs in HV substations Elghaffar, Amer Nasr A.; Mohamed, Yehia Sayed; Mohamed, Adel A. Elbaset
2017 Nineteenth International Middle East Power Systems Conference (MEPCON),
2017-Dec.
Conference Proceeding
The purpose of this paper to overcome the impact of electric and magnetic fields on the Intelligent Electronic Devices (IEDs) in High Voltage (HV) substations. The protection devices are considered ...one from IEDs in HV substation, that's will affect by this fields, this affection will lead to induced current in the secondary connection cables and all devices, that follows to errors in the measurements and the relay decision for the trip command at the fault occurs. So, the calculation of the fault location by the protection IEDs is not accurate. This paper shows the study results of the electric and magnetic field inside HV substation 500 kV, and the result curves shows how the Electromagnetic Field (EMF) vary under HV busbar 500 kV. This study uses the mathematical calculation with MATLAB software, where, the computation domain considered was the 2D free space case study results of a busbar 500kV in outdoor substation design.
Introducing matrix in islanding operation Anuar, M.A.; Elbaset, A.A.; Hiyama, T.
2009 Transmission & Distribution Conference & Exposition: Asia and Pacific,
2009-Oct.
Conference Proceeding
Splitting strategy is to ensure continuity of power system when islanding operation is unavoidable. Through the centralized control scheme, the dispatch center should decide which transmission lines ...to be opened to split original network into islands. This paper proposes a feasible splitting strategy by exploiting extended incidence matrix apart from neither random search nor the graph theory to determine the splitting strategy for the islanding operation. A concept using limited cutset elements was introduced with virtual network reconfiguration plan. The optimal system configuration is then to be chosen from those candidates to fulfill operational constraints. Operational constraints related to asynchronous generator, power imbalance and line capacity limits should be achieved. Simulation results on IEEE 30-bus test system show that this heuristic method is practical rather than analytical method.
The performance of photovoltaic power system interconnected with utility grid can be improved through an application of advanced control method. This paper introduces an application of an artificial ...neural network on the operation control of the photovoltaic/utility grid to improve system efficiency and reliability. The generated power from photovoltaic solar cells array have been calculated by a computer program under known insolation and temperature. The computer program which proposed here and applied to carry out these calculations is based on the minimization of the power purchase from grid. This paper focus on a hybrid system consists of photovoltaic system accompanied with battery storage interconnected with utility grid taking into account the variation of solar radiation and load demand during the day. Different feed forward neural network architectures are trained and tested with data containing a variety of operation patterns. A simulation is carried out over one year using the hourly data of the load demand, insolation and temperature at El'Zafranna site, Egypt as a case study. The results show that the selected neural network architecture (5+9+4) gives reasonably accurate operation of photovoltaic/utility grid accompanied with battery storage.
Olive by-products could be a suitable alternative feedstuffs ingredient in ruminants rations. This study was carried out to evaluate effects of replacing clover hay by olive cake with or without ...addition of poly ethylene glycol in growing lambs ration.
Thirty five Barki lambs averaged 34 kg body weight and 5 months old were divided into 5 groups (7 animals of each) according to live weight for 90 days feeding trial. Olive cake was treated mechanically by hummer mill, screened to produce screening olive cake (treated olive cake, TOC).
Data of dry matter and organic matter digestibility were decreased with ration containing 20% TOC from ration or 67% from clover hay comparing with others. No significant differences were observed among groups in crude protein digestibility. Total digestible nutrients (TDN) as an energy measurement for the experimental rations cleared that replacing process of clover hay by TOC up to 20% of DM intake or 67% of clover hay, given lower values (65.32 and 66.80%). The rumen pH values were not affected by the different experimental rations including control. The highest rumen NH3 was recorded with lambs fed ration containing 33% TOC without PEG instead of clover hay, while the lowest values was recorded with that group fed ration containing 33% TOC with PEG. No significant differences were detected in total gain, ADG as well as feed efficiency among the experimental rations. Dry matter intake slightly increased with feeding growing lambs on TOC containing rations except R5 compared to the control group.
Summing up partially de-stoned olive cake by screening could be used in replacing clover hay for growing lamb rations, at inclusion levels up to 33 and 67% with or without poly ethylene glycol, with no adverse on performance of growing lambs.
This paper presents a design and simulation of DC/DC boost converter. This system has a nonlinear dynamic behavior, as it work in switch-mode. Moreover, it is exposed to significant variations which ...may take this system away from nominal conditions, due to changes on the load or on the line voltage at the input. The input usually is obtained by PV array and therefore the design and simulation in this paper covers the whole range of radiations and temperature. In this paper we analyze the equations of a boost converter and propose a design components and simulation of DC/DC boost converter. This work is applied to photovoltaic system for tracking the point of maximum power.
The performance of photovoltaic power system interconnected with utility grid can be improved through an application of advanced control method. This paper introduces an application of an artificial ...neural network on the operation control of the photovoltaic/utility grid to improve system efficiency and reliability. The generated power from photovoltaic solar cells array has been calculated by a computer program under known insolation and temperature. The computer program which proposed here and applied to carry out these calculations is based on the minimization of the power purchase from grid. This paper focus on a hybrid system consists of photovoltaic system accompanied with battery storage interconnected with utility grid taking into account the variation of solar radiation and load demand during the day. Different feed forward neural network architectures are trained and tested with data containing a variety of operation patterns. A simulation is carried out over one year using the hourly data of the load demand, insolation and temperature at El'Zafranna site, Egypt as a case study. The results show that the selected neural network architecture (5+9+4) gives reasonably accurate operation of photovoltaic/utility grid accompanied with battery storage.
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