Journal of Advances in Science and Engineering
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Substation Ground Grid Design Using FEM Analysis
No full textA reliable substation earthing system is critical for power system stability and safety. This study presents the design and analysis of an electrical substation grounding system using the Finite Element Method (FEM) to ensure the safety of personnel and equipment. The design methodology, based on IEEE standards, was implemented using ETAP 16.0 software, considering a substation with a maximum expected short-circuit current of 40 kA. A two-layer soil model was used, and a square ground grid configuration (100 m x 100 m) was analyzed with and without vertical ground rods. The results demonstrate that while the overall ground resistance values were similar for both configurations (0.435 Ω with rods, 0.433 Ω without), the design with ground rods successfully maintained the calculated touch voltage (2391.4 V) below the tolerable limit (2832.5 V). Conversely, the design without ground rods was deemed unsafe, as the touch voltage (3876.3 V) exceeded the safety threshold. The findings confirm that FEM analysis is a reliable and effective tool for a detailed and realistic assessment of substation grounding systems, providing a flexible framework for designing grids that account for both present safety requirements and future system upgrades
Design and optimisation of wireless power transfer system for charging mobile phone
No full textIn light of the technological challenges in the current research trend of Wireless Power Transfer systems in today’s world, this paper puts forward innovative calculations, models, implementation and methods for optimising the coupling coil combining the state-of-the-art of the existing research. The results and analysis were done using MATLAB/SIMULINK. Wireless charging technology enables wireless power transfer from a power source (e.g., a charge) to a load (e.g., a mobile device) across an air gap. The technology provides convenience and a better user experience. Recently, wireless charging has been rapidly evolving from theories toward standards, and being adopted in commercial products, especially mobile phones and portable devices using wireless charging has many benefits. First, it improves user-friendliness as the hassle of connecting cable is removed. Different brands and models of devices can also use the same charger. Secondly, it eliminates the constant replacement or damage of the phone charging port. Thirdly, it enhances flexibility, especially for devices for which battery replacement or cable connection or charging is costly, hazardous or infeasible e.g. (body-implanted sensor) flouting wireless charging can provide on-demand power, avoiding an overcharging problem and minimising energy cost. The winder's power transfer system uses inductively coupled i.e. coupled magnetic fields to transfer electromagnetic energy from a charging base to a receiver in a portable device. This paper intends to achieve the wireless charging of mobile phones, optimise the efficiency of the charger, and simulate the circuit using MATLAB
Analysis of the transient conditions of a three–phase induction motor
No full textThe aim of this study is to build an experimental work bench and simulate a 4.1 kW (5.5HP) three phase induction motor in order to investigate the machine's transient behavior under various fault conditions. The method used in this study entails performing a series of experiments to determine the per phase parameters of the induction motor, such as no load tests, blocked rotor tests, and DC tests, and then implementing a model for the machine using MATLAB/Simulink in a graphical user interface environment. The machine's corresponding parameters were used to represent the model, and simulation was performed. The collected data were examined to identify the machine's operating characteristics under normal and transient circumstances. Results from this study reveals that the open circuit fault decays more slowly than the short circuit fault, and the peak current is almost twice that of the starting current. Although the transient is brief in duration and therefore unlikely to produce significant heating, it may cause high mechanical strains on the windings. The results demonstrates that the transient characteristics of an induction motor under various fault conditions may be determined entirely via computer simulatio
Development of wireless sensor nodes for data acquisition in petroleum pipelines
No full textData acquisition of parameters from oil and gas pipelines aids in the economic growth of any oil-producing nation; which in turn increases the efficiency, safety and lifespan of these pipelines significantly. This work focused on the development of the data sensors (pressure, flow and temperature sensors), Nodboxes and D-station. The Nodbox was designed using an ATmega 328p microprocessor as the control unit and an NRF 24l01+ transceiver as the wireless transmission path. Five (5) Nodboxes were designed; with one serving as the receiver at the D-station. A testbed was designed to demonstrate the reality of this system. MATLAB was used to design the GUI of the D-station to display and analyze data received graphically. Pressure, flow and temperature data were successfully transmitted from the pipeline network of the testbed to the D-station wirelessly up to a distance of 1.1km. It is cost-effective as it requires about 5 million naira to implement compared to existing systems
Evaluating the impact of injecting the 3050MW Mambilla power plant into the Nigerian grid network
Get PDFThe study aims to evaluate the impact of the injection of the 3050 MW Mambilla power plant into the Nigerian National Grid (NNG). To achieve this aim, line and bus data were collated from National Control Centre, Osogbo. The Mambilla power plant was injected at the Makurdi and Jalingo buses respectively in view of determining the optimal injection point. Load flow analysis employing the Newton Raphson technique was first performed without the Mambilla power plant injected into the NNG. The simulation was repeated for the respective power plant injection scenarios. For each case, the voltage profile and line losses were obtained accordingly. Total Voltage Deviations (TVDs) for the various scenarios were computed and used to determine the optimal point of injecting the Mambilla 3050MW power plant to NNG. All simulations were implemented using MATLAB software (version 2020b). A loss of 872.8 MW and 874.1 MW was observed in the network when the Mambilla power plant was injected at Makurdi and Jalingo bus respectively with respect to a base case loss of 876.1 MW. This corresponds to a reduction in a power loss of 0.36% and 0.12% respectively. A TVD of 0.0052 and 0.0169 was observed when the Mambilla power plant was injected at Makurdi and Jalingo buses respectively. This implies that the voltage condition of the network is better when Mambilla was injected at the Makurdi bus. Hence, the Makurdi bus was identified as the optimal point for injecting the Mambilla 3050 MW power plant since it resulted in a better reduction of the system losses and overall voltage profile improvement of the network
State-of-the-art methods for sentiment prediction
No full textSocial media sentiment analysis has become a trendy issue recently. It is used and supported by numerous organizations across many industries due to its useful applications. To obtain insights, marketers are keen to hear what customers have to say. The difficulties in acquiring, deciphering, and extracting useful information from the vast amount of data that is constantly generated have multiplied. Crunching social data is still difficult, despite advances in technology and increased computational power. This well-organized study is devoted to comprehending the current state of sentiment analysis as a whole, including typical techniques, gaps, and methodologies. This study uses a logical approach to find, acquire empirical data, critically evaluate, and integrate the findings of all relevant to respond to certain research questions about the specified research topic. Additionally, this research defines the various sentiment analysis types and methods. This study holds its significance in light of these two contributions
Design and development of an electric egg incubator for industrial use
No full textAn electric egg incubator developed using locally sourced materials is presented. The study aimed to produce a low-cost electric egg incubator to enhance the production of chicks for the poultry industry. The incubator comprised a body frame, turning mechanism, egg trays, humidity control pan, fan, heat source, and controls. The design and fabrication process of the egg incubator involved an appropriate selection of engineering materials for the various parts, design analysis, and calculations of the parts, detailed machine drawing using AutoCAD, parts fabrication, and assembling of the different components. The device was evaluated using percentage fertility and hatchability with 60 poultry chicken eggs. The test results showed 81.7% fertility and 58.3% hatchability at an incubation temperature range of 36.2 to 38. The unit cost of the incubator with a capacity of 60 eggs per production was ₦105,000. This study recommends incorporating a humidity sensory device for adequate humidity control, designing for a wider incubation temperature range for other poultry egg incubation and capacity improvement, and incorporating a solar power unit for a reliable supply
Optimal sizing of a hybrid photovoltaic/fuel cell grid-connected power system including hydrogen storage
Get PDFThe global energy demand is enormous, yet nonrenewable resources such as fossil fuels, and nuclear power are insufficient to satisfy it. Renewable energy will eventually be the better option. This study investigates the design and optimization of a hybrid photovoltaic / fuel cell (PV/FC) energy system with an H2 tank linked to the grid. The primary objective of this research is to design and size a PV/FC energy system with an H2 storage tank to supply the energy needs of a university ICT center that is connected to an inconsistent grid. HOMER's energy-balance algorithms were used to determine the best design architecture. Using mean solar radiation data (22 years) obtained for the University of Benin ICT Center, hourly simulations were performed to determine the optimum configuration in terms of size, cost, and performance of the energy system. Findings revealed that a hybrid PV/FC power system with a 400 kW solar array, a 250 kW FC, a 240 kW inverter, and a 150 kW electrolyzer with an H2 tank of 700 kg will reliably supplement the inconsistent grid with a high proportion (92%) of renewable resources at 98,251,110 could be obtained in less than 2 years over the traditional grid/diesel systems. Using an ideally sized PV/FC hybrid system will alleviate Nigeria's electrical challenges, impeding the country's economic growth. Furthermore, hybrid PV/FC power systems can reduce CO2 emissions, resulting in a more environmentally friendly and sustainable environment
Comparative analysis of the economics and reliability of pure solar energy and utility supply
No full textThe increasing demand for energy and the need to transition to renewable sources has led to a growing interest in the use of solar energy. This paper conducts a comparative analysis of the economy and reliability of pure solar energy systems and utility supply in a small load area. The energy requirement of the chosen load area was estimated and the appropriate sizing of the solar system was made. The study uses the payback period method to estimate the economy and the Monte Carlo method to estimate the reliability. Load estimation was performed to determine the appropriate solar systems, which were then modelled using PVSyst. The results of the study show that solar energy can be a cost-effective and reliable alternative to utility supply; with a consistent maintenance cost of 4 % per annum, the return on investment was calculated to be 14.1 % per annum at a supply current tariff of ₦ 61.34 per kWh. The payback period showed that the investment in a solar photovoltaic (PV) system can be recovered in six years and nine months (6 years, 9 months). The Monte Carlo simulation demonstrated the reliability of the energy supply in a solar PV system compared to the Nigerian utility supply with the reliability index of the solar system being 93.81 % and that of the utility supply at 55.73 %
Design of an automatic load monitoring and load shedding device
No full textOver time, the negative impact of overload in the distribution system network has resulted in a growing need for a more sophisticated control and monitoring system. Several methods have been limited to monitoring the electric power, power system loading level and transfer load from one feeder to another. To this end, this study focuses on designing an automatic load monitoring and load shedding device, a Supervisory Control and Data Acquisition (SCADA) device designed for utility and the University of Benin Teaching Hospital (UBTH) distribution system to prevent contingency. The method adopted is based on the load audit report carried out on the UBTH distribution network. A model is proposed, and the load audit report is used to structure the UBTH distribution network into critical and essential load demands. Each feeder is monitored, and priority is given to critical loads during load shedding. Finally, a prototype of an automatic load monitoring and load shedding device is designed and implemented with the capacity to perform the desired function. The efficiency of the proposed system is evaluated by carrying out a monitoring test, loading test, control test and converter test, which all tested satisfactorily