The Uninterruptible Power Supply Explained

The main purpose of a An Uninterruptible Power Supply is to ensure the constant supply of power to equipment or devices, even when the main power cuts.

Where do you use a UPS?

You would use a UPS in many situations:

1. At home to protect your computers and IT hardware from power fluctuations and power cuts.
2. In enterprise industries where up time is paramount to the success of the business.

Different types of UPS systems

The most common type of UPS systems on the market today include: standby, line interactive, standby-ferro, double conversion online and delta conversion online


This UPS is most commonly used for personal computers. These UPS systems has a built in inverter which is in “standby mode” and only activates when the power is cut to the ups system. These UPS systems are great in efficiency, they small in size and relatively in expensive.

Line Interactive

These UPS systems provide an automatic voltage regulation when low or high voltage conditions occur. They also have better battery performance as it does not switch to battery mode during brownouts, and sits between a standby and online ups in terms of cost and performance. They also provide provide protection from spikes and surges


These UPS depend on a special saturating transformer that has three windings (Power Connections). The primary power path is from AC input, through a transformer switch, through the transformer and to the output. When the power trips, the transfer switch is opened and the inverter picks up the load. These systems are generally marketed as online UPS systems even though they built with a transfer switch.

Double Conversion On-Line

This is the most common type of UPS above 10kVA. The Double Conversion On-Line UPS, is the same as the Standby, except that the primary power path is the inverter instead of the AC main. This UPS provides nearly ideal electrical output performance. But the constant wear on the power components reduces reliability over other designs and the energy consumed by the electrical power inefficiency is a significant part of the life-cycle cost of the UPS

Delta Conversion On-Line

This UPS design, is a newer, 10 year old technology introduced to eliminate the drawbacks of the Double Conversion On-Line design and is available in sizes ranging from 5kVA to 1.6MW
The Delta Conversion On-Line UPS provides the same output characteristics as the Double Conversion On- Line design. However, the input characteristics are often different. Delta conversion on-line designs provide dynamically-controlled, power factor corrected input, without the inefficient use of filter banks associated with traditional solutions. The most important benefit is a significant reduction in energy losses.