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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 Implementation of an Automatic Changeover and Phase Selector System
No full textAlternative sources of power like generators and solar panels are inevitable due to the erratic nature of the power supply in Nigeria, which is caused by increased consumer demand and poor infrastructure maintenance, An automatic switching system is necessary to prevent a disruption in the power supply. This study presents an automatic changeover and phase selection system that is coupled to the power supply. In order to properly isolate, switch, and show switching states through the integration of hardware, the design utilizes contactors and timer relays. The automatic phase selector and changeover switch is contactor based; it incorporates contactors, relays and timers to transfer the load to alternative supply when the primary source (public utility) supply fails and also monitoring the public utility when power is restored transferring back the load to the public utility. The switch is tested to operate efficiently within a range ±5% of the nominal voltage of 220V, the switch requires approximately 4 seconds to transition between power supplies. This developed device will significantly enhance power transition time, particularly for low to middle-income families who may find industrial automatic transfer switches expensive due to their high cost
Minimization of Distribution Cost for a Paint Distributing Company
No full textThis study employed Excel Solver to find the monthly total minimum and maximum costs of distributing buckets of gloss paint by Ehi-sly Enterprise Limited to its nine major customers. The monthly total minimum cost was then compared with the monthly total maximum cost and the potential saving was determined. The company has two warehouses and nine major customers dispersed within three localities, Uromi, Ubiaja and Irrua in Edo State. The monthly inventory levels of the two warehouses and the price of distributing a bucket of gloss paint from each of the warehouses to its various customers coupled with the customers’ monthly orders were used in the cost minimization and maximization. From the results obtained, it is shown that the monthly total minimum cost of distributing the ordered buckets of gloss paint to the nine customers is ₦4,384,000 as against the monthly total maximum cost of ₦8,042,500. This indicated a potential monthly saving of ₦3,648,500 which can boost the company’s profit margin
Design and Development of an Infrared-Based Home Security System
No full textThe development of intruder detection, employing a passive infrared (PIR) sensor detecting intruders in a secured site, incorporating GSM technology for real-time security notification is presented in this study. This smart home security system was designed to enhance security in residential homes and areas considered. The principal devices used are PIR sensors for motion detection, a microcontroller for operation control, and a SIM900 as a GSM module for data transfer. Motion detection is based on the principle of infrared radiation produced by the heat generated by the human body which triggers the PIR sensor. The microcontroller processes the signal received from human motion and then buzzes the alarm. The microcontroller activates the GSM module and sends an SMS message to the user’s mobile device. This enables the user to get information in real time. The message received by the house owner’s mobile device activates the house owner of the next line of action. During the test circle, the number of times humans passed the sensor was fully captured by the PIR home-based security system and messages were received in the shortest period (3 – 5 s). The number of messages received by the mobile device of the house owner equals the number of times there was human interference. The system’s simplicity in design makes it dependable, and reliabl
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
Design and Implementation of a Wireless Automated Water Level Monitoring and Pump Control System
No full textOur world is facing excessive water usage either for domestic or commercial purposes and it is a serious issue, which affects the sustainability of our environment. This study investigates the design and implementation of a wireless automatic water level sensor device that can accurately detect and regulate water levels in a designated water tank or similar water storage system. The system first identifies the water level in the tank through the utilization of sensing probes. Output from the probe is encoded and transmitted through radio frequency (RF) signals, which are then received and decoded by the designated receiver. The processed information is displayed on an LCD, providing visual feedback as the system adjusts the operation of the water pump according to the water level data. This design achieves automation through the use of sequential logic, utilizing a microcontroller, an LCD, and a relay-driven motor pump circuit. The water pump is configured to engage autonomously, commencing the filling operation when the water level reaches the empty state or level ONE. It will stop operation and halt the filling process once the water level attains the maximum threshold of level FIVE. The pump will remain in a standby state from level FOUR to level TWO as the water level drops due to usage. This automated system enhances water management by minimizing human intervention while ensuring that the storage tank consistently maintains optimal water levels
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
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 %
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
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