Electrical Power Engineering
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- ItemA HYBRID FIREFLY-GENETIC ALGORITHM FOR THE OPTIMAL COORDINATION OF DIRECTIONAL OVERCURRENT RELAYS(2023-02-19) Tareq Husam FoqhTheoretical background: Directional overcurrent relays are applied for power system protection to ensure safe, reliable, and efficient operation. The coordination of directional overcurrent relays is non-linear and highly constrained optimization problem. The main goal of the optimization is to minimize the summation of operating times of primary relays, by setting optimal values for decision variables as time multiplier setting (TMS) and plug setting (PS). Aims: The main objective of this research is to develop a hybrid optimization algorithm which consists of modified firefly algorithm and genetic algorithm to find better solutions. Methodology: First, this study modified the original firefly to obtain a global solution by updating the firefly's brightness and to avoid the distance between individual fireflies from being too far. Additionally, the randomized movements were controlled to produce a high convergence rate. Second, the optimization problem is solved using standard genetic algorithm. Finally, the solution obtained from the modified firefly algorithm is used as the initial population for the standard genetic algorithm. The modified firefly algorithm, genetic algorithm and hybrid firefly-genetic algorithm have been tested on IEEE 3-bus, 8-bus, 9-bus and 15-bus networks. Main Results: The results indicate the effectiveness and superiority of the proposed algorithms in minimizing the overall operating time of primary relays compared to other algorithms mentioned in the literature for directional overcurrent relays coordination. Conclusion: Compared to modified firefly algorithm and standard genetic algorithm, the proposed hybrid algorithm has minimized coordination interval time between primary and backup relay pairs. Keywords: Directional overcurrent relays optimization, Hybrid algorithms, Firefly algorithm, Genetic Algorithm.
- ItemDESIGN A FUZZY LOGIC CONTROLLER TO CONTROL ACTIVE POWER FILTER FED BY MULTILEVEL INVERTER AND PHOTOVOLTAIC(2023-09-11) Ghadeer Ahmad AbduhNew electrical systems commonly use nonlinear loads, which increase harmonic pollution in the primary power system. When power electronic equipment with semi-conductors is utilized, harmonic currents occur, affecting quality of power and generating non-sinusoidal currents taken from the AC sources. This result in a current discontinuity and an increase in the system's harmonics. Harmony in the power network generates a variety of issues, including voltage deformities at the Point of Common Coupling (PCC), altering peak and RMS values of line used, and a variety of other issues. In addition to the challenges caused by harmonic current, reactive power is another problem with the quality of the electricity in the power system. To improve the quality of the power delivered to the network, electrical filters must be employed to cancel harmonics and reactive power. The power quality is developed using a variety of filter topologies, including passive, active, and hybrid. A shunt active filter is employed in this project to increase the quality of the electric power. This active filter can perform a variety of tasks, including reducing harmonics, adjusting reactive energy, improving Power Factor (PF), inserting real power source. The primary goal of this project is to apply a fuzzy logic controller to optimize the performance of the Shunt Active Power Filter in order to lower harmonic distortion. To decrease the harmonic current and raise the power factor to unity, the Fuzzy Logic Controller for the three-phase Shunt Active Power Filter is intended to replace the Proportional Integral controller. The results were confirmed from the calculated values of the THD of the source currents. The THD was reduced from 16.67% before using the APF to 2.62 % after using the APF for PI controller and 16.67% to 1.42% for FLC. These results of the THD for FLC is even better than the results obtain of PI controller. MATLAB/SIMULINK has been used in this study to combine various renewable energy sources with a 27-level H-Bridge multi-level inverter with a shunt active power filter. The system has been built to function in a variety of operational scenarios. Keywords: Fuzzy Logic Controller, Shunt Active Power Filter, Photovoltaic,Multilevel Inverter, Total Harmonic Distortion.
- ItemDesign And Analysis A Solar System For A Villa(2022) Mohammad Yasin; Ayham OstaThere are numerous energy sources available, but their proportional utilization in the globe and in Palestine is not equal. We rely largely on electricity supplied by Qatari electricity businesses operating within the occupied country, which is delivered throughout Palestine via multiple connecting points. Installing solar cells and relying on them, (at least in part ), for daily use to minimize network pressure and deliver long-term economic savings Solar cells are designed in two examples for a villa in the Tulkarm area, one connected to the grid and the other disconnected from it. From shadow analysis to estimating the vacant spaces and loads in the house, we examined all of the design criteria. Also, based on studies and values taken over 20 years, including changing temperatures, the region was analyzed in terms of the sun's path throughout the year and the amount of radiation emitted by it, and finally, the used categories of inverters, batteries, solar cells, and everything else the system requires were chosen.
- ItemPV multi-level based Grid(2021) Shoubi Razan; Shashtare Zenat; Nofal YasmeenPHOTOVOLTAIC (PV) power supplied to the utility grid is gaining more and more visibility, while the world’s power demand is increasing. Solid state inverters have been shown to be the enabling technology for putting Photovoltic PV system into the grid. 2-level inverters are used to convert the DC voltage optained from the Photovoltic system to AC voltage fed to the utility. However, the use of 2-level inverters causes an increase in the Total Harmonic Distortion (THD) and other Power quality issues due to the harmonics injected by the such inverters. Increasing attention has been paid to multilevel dc/ac inverters in recent years to obtain output voltage of high quality. One of the more flexible topology is the asymmetric cascaded H-Bridge multilevel inverter, which will be employed in the project to improve the quality of the output voltage by reducing the harmonic contents. The project consists of two modules: power circuit and control circuit. The power circuit consists of two H_bridges forming an eight- level inverter. The ratio between DC voltage of the two H-Bridges will be 1:3. This will help to generate maximum number of levels and generate output near sinusoidal. The control circuit include the using of a microcontroller and current and voltage sensors to generate PWM signal to H-bridges and control the injection of real and reactive power inject to the grid. The whole structure of the project will be shown in Figure 1 ( Attached is a file showing the figure) . Experimental and simulation results using matlab /simulink will be presented to show the improving of the power quality using the multilevel inverter.
- ItemAnalysis of Power Conversion Stages and Efficiency Improvement Possibilities for Grid Connected Pv System.(Eman Omar Mahmoud Abu Hani, 2018-04-10) Abu Hani, EmanIn this thesis the improvement of large scale PV system conversion efficiency is presented. Mainly the inverter efficiency is considered to be improved by testing two different configurations of 100 kWp PV. The first configuration consists of one single centralized inverter and the second one of master-slave inverter. A Mathematical model is developed by MATLAB software to model the inverter efficiency as a function of input power then the power output is calculated by using hourly solar radiation and ambient temperature data over one year in Palestine. The simulation results show that the annual average energy production using the single centralized inverter is 181.26 MWh/year, while the annual production of master-slave inverter is 184.5MWh/year. In addition, by considering only the inverter efficiency the annual efficiency of DC/AC conversion stage for first system is 96.7% and for the second system is 98.4%. Economic analysis shows that the additional investment in master-Slave configuration instead of using single centralized inverter can be covered within six and a half years.