DEPARTMENT OF ELECTRICAL/ELECTRONICS ENGINEERING

This study examines the performance of the ZigBee Received Signal Strength Indicator (RSSI) in indoor environments, with a focus on understanding how distance and environmental obstacles influence wireless signal propagation. The research was conducted at the Faculty of Engineering, University of Benin, utilizing two ZigBee Pro S2B modules configured through XCTU software. Measurements were taken at distances ranging from 10 feet to 50 feet, under various conditions involving obstacles such as furniture, walls, and human presence. The findings indicate that RSSI values exhibit a progressive decline with increased distance and greater obstacle density. Specifically, the signal strength diminished by approximately 4 to 6 dB for every 10-foot increment, with an additional decrease of 3 to 5 dB for every two additional obstacles encountered. It was determined that walls and human presence are the most significant factors contributing to signal attenuation, due to effects related to reflection, absorption, and scattering. These results are consistent with theoretical path loss models and corroborate prior empirical studies, reinforcing the notion that the performance of ZigBee technology is significantly influenced by environmental conditions. The study concludes that ZigBee is well-suited for short-range, low-power Internet of Things (IoT) and sensor applications; however, optimal node placement and the implementation of mesh networking are critical for ensuring reliable communication in complex indoor environments. The insights derived from this research hold valuable implications for enhancing the design and deployment of wireless sensor networks in academic and smart-building contexts.

The aim of this project is to carry out a comparative evaluation of foreign and homebased manufactured hybrid 3.5kva inverter system. Conventional non-hybrid inverter systems are characterized by their dependency on the grid, low efficiency in solar charging, limited energy management capabilities, and ineffective communication between components. Therefore, this endeavor is designed to integrate hybrid features to overcome these shortcomings. The process entailed comparing a hybrid inverter system to address the limitations of non-hybrid inverters and to do this, we incorporated an alternative power source, i.e. solar energy, to charge the battery. This involved designing an MPPT (Maximum Power Point Tracking) charge controller and seamlessly integrating its circuitry with that of the inverter in the non-hybrid system. Additionally, we established effective communication between the DSPIC30F2010 microcontroller on the inverter and the DSPIC30F2010 microcontroller on the MPPT circuitry using serial communication, which we integrated into the inverter. All communication protocols were outlined in the source code. To ensure organization and tidiness, we housed all these components within a single enclosure. The project successfully achieved its intended objectives by comparing the hybrid features of the homebased and foreign manufactured inverter systems. Through meticulous design and implementation, all identified limitations were effectively addressed, leading to significant improvements in system performance and functionality. Relevant tests such as output voltage and frequency test, load and no load test, as well as power efficiency tests were carried out to compare the performances of the foreign and home based manufactured hybrid inverter systems. The performance of the home based hybrid inverter was 219.8V for output voltage versus 230V for the foreign. Frequency for home based was 50.04Hz versus 50.0Hz for the foreign. Both inverters displayed a comparable sine wave output. Power efficiency for home based was 90.64 percent while for foreign, it was 94.5 percent, these results show that there was no remarkable difference between the output of the home based compared to the foreign inverter. Furthermore, the locally assembled inverter cost far less than the foreign counterpart. Hence, this study proves that cost efficient inverter systems can be manufactured locally.

The chronic unreliability of Nigeria's national power grid necessitates a dependency on costly and environmentally damaging diesel generators, particularly for critical institutions like universities. The literature validates Hybrid enewable Energy Systems (HRES), specifically the Photovoltaic (PV)-Diesel-Battery configuration, as a technically superior and sustainable alternative for offgrid power. However, a granular, site-specific reliability assessment for the unique and energyintensive load profile of a Nigerian engineering faculty represents a significant gap in existing research. This study addresses this gap by providing a bespoke techno-economic analysis and reliability evaluation for a standalone hybrid power system for the Faculty of Engineering at the niversity of Benin.This research adopts a simulation-based methodology centered on the Hybrid Optimization Model for Multiple Energy Resources (HOMER) Pro software. The analysis is founded on a comprehensive on-site electrical load survey, which determined the faculty's detailed operational patterns and an annual energy demand of 737,686 kWh. This granular, real-world load profile, along with local solar irradiance and ambient temperature data for Benin City, was used to model, simulate, and optimize thousands of system configurations. The primary objective of the optimization was to identify the component sizing (PV array, battery bank, and diesel generator) that meets the faculty's load with the highest reliability at the lowest possible life-cycle cost.The simulation results identified an optimal system configuration consisting of a 525 kW PV array, a 198 kWh Battery Energy Storage System (BESS), and an 85kW diesel generator relegated to a backup role. This system achieves 100% reliability with zero unmet load, a 100% renewable energy fraction, and a highly competitive Levelized Cost of Energy (LCOE) of ₦0.0548/kWh. The analysis confirms that this configuration completely displaces the need for diesel fuel, thereby eliminating significant operational costs and preventing approximately 553 tonnes of CO2 emissions annually. The findings conclusively demonstrate that a properly sized PV-Battery hybrid system is a technically reliable, economically superior, and environmentally sustainable solution to the faculty's energy challenges.

The existing landscape of real-time communication often relies on traditional wire intercom systems which are characterized by high installation costs, complex wiring, and inherent flexibility, posing significant challenges for scalable deployment in dynamic environments. These limitations necessitate a modern, cost-effective, and easy-to-deploy solution that utilizes existing infrastructure. The primary aim of this project is to address this deficit by designing and implementing a functional, low-latency 4-channel Wi-Fi ( Wireless Fidelity) Local Area Network (LAN) based wireless intercom system capable of facilitating clear, full-duplex voice communication among multiple users. The system methodology centered on a decentralized, peer-to-peer architecture utilizing ESP32 microcontroller for its integrated Wi-Fi capabilities and dedicated I2S (Inter integrated sound ) digital audio interface. Audio quality was managed by pairing an INMP441 digital microphone with a MAX98357A digital amplifier, eliminating analog noise and circuit complexity. Crucially, communication over the LAN was executed using the User Datagram Protocol (UDP) instead of Transmission Control Protocol (TCP). This deliberate choice minimized packet overhead and connection management, which is essential for ensuring the reliable, low-latency data transmission required for real-time conversation. Testing confirmed the successful two-way voice transmission between all intercom units, with the system consistently demonstrating an end-to-end latency below the critical 150ms threshold required for human-perceptible real-time conversation. In conclusion, the project successfully validated the technical feasibility of leveraging commodity Internet Of Things (IoT) hardware for sophisticated communication tasks. The resulting system is a significantly more scalable and cost-effective alternative to legacy wired intercoms, demonstrating a framework for future development in affordable, high performance wireless communication product

The principle of Maximum Power Transfer dictates that for a source to deliver maximum power to a load, the load impedance must be equal to the complex conjugate of the source impedance. In practical power delivery systems, particularly those with dynamic or reactive loads, this condition is rarely met, leading to significant power loss and reduced system efficiency. This project addresses the challenge of impedance mismatch by designing and implementing a Smart Load Matching Circuit that utilizes a microcontroller-based system to dynamically adjust the transformer tap position. The system employs voltage and current sensors to measure real-time source and load parameters, allowing the central Arduino microcontroller to calculate the instantaneous impedance. Based on a predefined control algorithm, the Arduino activates a bank of Single-Pole Double-Throw (SPDT) relays to switch the multi-tap transformer to the optimal winding ratio, thereby achieving the closest possible impedance match. The primary objective is to maximize power transfer efficiency under varying load conditions. The implementation and testing of this circuit demonstrate a significant improvement in power transfer efficiency compared to a fixed-tap system, validating the use of smart, dynamic control in addressing impedance mismatch in power electronics.

Many rural areas in Nigeria lack access to reliable electricity, making everyday tasks like mobile phone charging difficult. To address this issue, this project focuses on the design and development of a mobile solar charger that provides a sustainable, off-grid charging solution for remote communities. By harnessing solar energy, a clean and renewable resource, the system offers an eco-friendly alternative to conventional grid-based charging, enabling individuals to charge their phones without depending on unstable electricity infrastructure. The design process involved careful selection of components to ensure efficiency, durability, and high power output. The system integrates a solar panel, a Maximum Power Point Tracker (MPPT) to optimize power extraction, a rechargeable battery for energy storage, and a synchronous buck converter to regulate the power supplied for charging. To enhance portability and durability, a custom enclosure was fabricated using iron angle bars and sheets, with cutting, welding, and assembling techniques used to create a lightweight but robust housing for the components. The final system can charge up to twenty mobile phones simultaneously, making it a highly efficient solution for rural areas with high demand for mobile power. By incorporating MPPT technology and efficient power conversion, the system ensures maximum energy utilization even in fluctuating sunlight conditions. This project provides a scalable, cost-effective, and sustainable solution to improve connectivity in underserved communities, empowering them with a reliable source of power for mobile communication.

This research project touches on the simulation, design and applications of a Solar Charge Controller to enhance the performance of a Photovoltaic system. Solar charge controllers are devices that helps regulate the flow of voltage and current from solar panels in order to prevent over-charging or over-discharging of the batteries acting as a regulator. They are essential to the management of the charge and discharge of batteries through the regulation of their currents and voltages in order to increase and improve the lifespan and efficiency of batteries. This study explores the design, simulation, implementation, test and evaluation of a solar charge controller including calculations for its voltage, current, power, capacitance and inductance. A detailed description of various components used to design the solar charge controller is also provided as well as the simulation and test results on the solar charge controller.

Motion detection is now crucial for modern security frameworks and energy conservation efforts, offering superior protection and mitigating energy waste from appliances left running. This project addresses the need for a reliable, economical, and highly effective sensor system by focusing on the design, construction, and testing of a Passive Infrared (PIR) Motion Sensor prototype. The primary goal is to create a robust device capable of identifying movement across a complete three hundred and sixty degree field of view, enhancing its utility over standard directional sensors and providing a valuable contribution to localized security solutions. The technical implementation began with a robust Power Supply Unit built from scratch. This unit uses a step down transformer, a full wave bridge rectifier, and a large smoothing capacitor to transform high voltage AC into smooth DC. An LM7805 voltage regulator guarantees the stable five volt supply essential for the sensitive electronic components. The Sensing Circuit uses a PIR sensor and a Fresnel lens to detect infrared energy. The weak analog signal generated by moving heat sources is processed by an operational amplifier and a comparator to create a clear digital trigger. This trigger then activates a transistor to energize an electromagnetic relay and a buzzer, which serve as the system's immediate response mechanism. Testing confirmed that the prototype successfully met all objectives. This included the reliable detection of motion within the predetermined area, the empirical definition and adjustment of the effective detection range, and the successful fine tuning of system sensitivity. Furthermore, the strategic design achieved the critical goal of wide coverage. This project validates the construction of a low cost, energy efficient device, affirming the practical application of knowledge in electronics design, power management, and embedded systems, and establishing a successful framework for automated lighting and intruder alarm systems

Over speeding is one of the major causes of road accidents and loss of lives. This project/research presents a system for speed detection, measurement and reporting using an Arduino microcontroller/board coupled with a sensor of our choice (tentatively Radar or Infrared sensor).

This project assessed the feasibility of implementing a 1KVA solar power system as an alternative energy solution for an office experiencing frequent power outages. The study aimed to determine whether such a system could reliably fulfill daily energy requirements while remaining cost-effective long-term compared to conventional power sources. The investigation addressed both energy security—reducing reliance on unstable grid electricity—and environmental sustainability through lower carbon emissions. The research examined how small-scale solar installations could prevent operational disruptions while supporting sustainability goals, and whether savings from eliminated electricity bills and generator fuel costs could justify the initial investment in renewable technology. The methodology employed a three-phase approach beginning with an energy audit to quantify power requirements by documenting all electrical equipment and measuring actual consumption patterns. This was followed by a cost-benefit analysis comparing the solar system's upfront investment against projected long-term savings. Implementation involved installing a complete 1KVA system with strategically positioned photovoltaic panels, appropriate deep-cycle batteries, and calibrated inverters. The system underwent performance monitoring under various conditions, collecting data on power generation, battery cycles, and load management. A maintenance protocol was also established, outlining inspection procedures and troubleshooting guidelines to ensure optimal system performance and longevity. Findings confirmed the 1KVA solar system effectively met the office's energy needs, providing sufficient power for essential equipment with battery reserves covering low-sunlight periods. Despite initial costs being 2.5 times higher than conventional solutions, financial analysis projected complete return on investment within 3.2 years through eliminated utility bills and fuel expenses. Environmental assessment showed carbon emission reductions of approximately 2.8 tons annually, while the system improved operational continuity by eliminating power-related downtimes. With proper maintenance, components maintained over 90% efficiency after one year of operation. These results demonstrate that appropriately sized solar systems offer a viable, sustainable alternative for small offices, delivering reliable energy security alongside long-term economic and environmental benefits despite higher initial investment requirements..