THE DESIGN AND CONSTRUCTION OF AN UNINTERRUPTED POWER SYSTEM (UPS)

THE DESIGN AND CONSTRUCTION OF AN UNINTERRUPTED POWER SYSTEM (UPS)

ABSTRACT

With the help of a step-up transformer, this uninterruptible power supply device can convert from 12volts D.C to 220volts alternating current at a frequency of 50Hz. The primary function of this device is to ensure absolute power continuity to the computerized control system, thereby protecting critical equipment from electrical supply failure. The UPS system accomplishes this by rectifying the power supply, using direct current to charge the standby battery, and producing “clean” alternating current via an inverter and filter system. The output is free of service voltage sags, frequency variations, spikes, and transients.

1.0            INTRODUCTION

A DC-AC inverter is essentially a device that converts direct current to sinusoidal current. There are various methods for performing this conversion in order to achieve a more reliable and efficient system. When there is a power outage in the house, this system is designed to generate 50Hz sinusoidal and 220volt alternating current with a total power of 200watts to power sensitive equipment such as computers and communication equipment, as well as to provide an emergency light and power to some essential household appliances. The desire to start the project arose from knowledge of the problem and discomfort that Nigerians experience when their homes or offices lose power.

Even with generating sets, the user load will not immediately resume power when the failure occurs. where sensitive equipment, such as biomedical and telecommunications equipment, where a brief loss of power could result in equipment breakdown or data loss, requiring more labor to recreate (in the case of computers) or resulting in death in hospitals where such equipment was on power supply

1.1            PROJECT OBJECTIVE

An uninterrupted power supply has been designed and built to address some of these shortcomings. This was accomplished using rectifiers and an inverter with a backup power source. The unit is always in circuit when the supply authority is delivering power, which is an intriguing aspect of this system. A battery charger, automatic control system, inverter unit, battery (dc-source), and a step-up transformer are the only requirements. When the power is turned on, the mains charges the battery, and in the event of a power outage, the load none draws power from the battery via an automatic changeover switch.