POWER SYSTEM

This project focuses on the design and building of a solar inverter with a 3.5KVA capacity. Solar inverters convert the variable direct current (DV) output of a photovoltaic (PV) solar panel into utility-frequency alternating current (AC), ready for connection to a home's electrical system. It is essential to solar systems since it permits the use of common AC-powered devices. Solar panels in solar inverters produce direct electricity by moving electrons from a negative to a positive direction. Most home appliances run on alternating current. This AC continuously fluctuates between negative and positive elections. You can adjust the voltage in the AC power according to the equipment's intended use. Solar inverters convert DC to AC because solar panels can only provide direct current.We created a 3.5KVA electrical inverter for this project. Two 22Ah wet cell batteries, a 220V/24-0-24V center-tapped inverter, an MPPT charge controller, and six 300W solar panels make up the architecture of the inverting circuitry assembly. The design provided power for a television, refrigerator (200 watts), air conditioner (1120 watts), and other devices totaling 2465 watts. The system operated at peak efficiency for almost 12 hours while under full load.

The previous system which had a 3.5KVA, 48V inverter, eight(8) 12V, 220AH wet cell batteries and eight(8) 150W, 24V solar panels was disconnected. A new inverter which is a hybrid inverter of rating 7.5KVA, 48V was purchased alongside with four(4) 12V, 220AH wet cell batteries. The panels which were placed on the roof 500m from the stationary unit was cleaned up with wet rags and mild detergent, and the eight(8) old batteries were cleaned up and revamped by addition of distilled water and the batteries were arranged in three(3) frameworks (four to each). A framework containing the four(4) new 12V batteries connected in series to give a steady voltage of 48V were connected to the 7.5KVAinverter of which also had the solar panels connected to it. These connections made up Unit A while the other two framework which had the four(4) old 12V batteries connected in series each (making up 8 batteries) were connected together in parallel to make up for the steady 48V and then connected to the 3.5KVA inverter which was connected to a 48V, 50A charge controller on which the solar panels were connected to. These connections made up Unit B. Unit A was made to supply the departmental offices and the lecturer offices which carries more load while Unit B was made to supply the 400level, 500level class and other few minor devices which had less load. The integration of both Units and the separation of loads led to a more efficient and reliable PV system for the department of Mechanical engineering as the alternate source of power can now be used for longer hours without powering down.

The project involved detailed load analysis, component selection, and system configuration. The final design ensures a stable power supply with provisions for future scalability. This work demonstrates the practical application of electrical/electronic engineering principles in solvingreal-world energy challenges and contributes toward the goal of sustainable development. In this project, the design of a 300kW stand-alone power system for the faculty of Engineering, implementation of a 10kW inverter/battery system for the Dean’s office, LT1, LT2, LT3, LT4 and the faculty board room was carried out.