UPS stands for uninterruptible power supply. It provides battery backup power when utility power fails or drops to an unacceptable voltage level, switching over within 2-4 milliseconds to prevent disruptions. A UPS connects between the power utility and electronic loads like computers to maintain power instantly during outages or voltage fluctuations. It conditions the power by reducing spikes, sags, surges, brownouts, and other problems. There are three main types: offline UPS draws power from the battery during outages, line interactive uses the battery during sags and surges, and online UPS provides continuous battery backup power with the fastest switchover time.

1. WHAT IS UPS
INTRODUCTION
UNINTERRUPTIBLE POWER SUPPLY is a device that provides battery
backup when the power fails or drops to an unacceptable voltage level The
Switchover time must be small (2 to 4 ms) enough to not cause break in the
operation of the loads
What is UPS ?
Uninterruptible Power Supply is standby electrical Power source connected between the
Power Utility and the load.
Modern Electronic gadgets and computer systems are highly sensitive to the power
fluctuations• Disruption of power may lead to Data loss/corruption/ malfunction etc.• Standby
Power Sources - Generators• Starting the generator takes a few minutes.UPS is mainly used
as a Power Backup forth above few minutes.
UPS maintains power instantaneously by switching to battery in the event of a power
failure or a dip (brown out)• Used to condition the power supply by reducing spikes and
harmonics.• Designed to correct a variety of power problems - - Sags – Transient Under
voltage - Surge – Short duration high voltage - Brownouts – Low voltage for long time - Spikes
– Brief but high energy bursts - Line noise, frequency variation, switchingtransient and
Harmonic distortion
Three types of UPS
1Offline UPS
2 Line interactive Ups
3. Online UPS

3. Online UPSMain components of UPS
Rectifier / Battery Charger - Battery - Inverter Main features for a Good UPS: -
Shortest changeover time < 4mS - Sufficient battery backup time - Quality output
supply

4. Online UPSElements of UPS:
- Input - Rectifier / Battery Charger - DC System - Inverter - Output - Static Bypass