Design and Construction of Uninterruptible Power Supply (UPS) System

ABSTRACT

This project presents the design and construction of Uninterruptible Power Supply (UPS) system with an apparent power output of 500VA (0.5KVA). This was achieved by the use of transformer, rectifier, inverter circuit, battery, full wave rectification, change-over circuit and filtering was implemented by the use of smoothening circuit using capacitors. We used an inverter that deliver an alternating current (a. c.) of 220V, 50Hz and the output voltage is made to have enough power to drive 4' 4 the load connected to it. The output from the inverter is synchronized in frequency and magnitude with the external power supply so that at power outage, the battery back — up inverter then supply power to the load ensuring that the power supply to the load is uninterrupted. This project provides a clean dependable supply of alternating current free of surges, frequency variation and transients and it is also used as back-up for electrical appliances to maintain a continuous supply of electric power.