UPS Technologies Types

1. Offline

The Offline / Standby UPS (SPS) offers only the most basic features, providing surge protection and battery backup. With this type of UPS, a user's equipment is normally connected directly to incoming utility power with the same voltage transient clamping devices used in a common surge protected plug strip connected across the power line.

When the incoming utility voltage falls below a predetermined level the SPS turns on its internal DC-AC inverter circuitry, which is powered from an internal storage battery. The SPS then mechanically switches the connected equipment on to its DC-AC inverter output.

The switchover time can be as long as 25 milliseconds depending on the amount of time it takes the Standby UPS to detect the lost utility voltage. Generally speaking, dependent on the size of UPS connected load and the sensitivity of the connected equipment to voltage variation, the UPS will be designed and/or offered (specification wise) to cover certain ranges of equipment, i.e. Personal Computer, without any obvious dip or brownout to that device.

2. Standby
The Standby UPS is the most common type used for Personal Computers. the transfer switch is set to choose the filtered AC input as the primary power source (solid line path), and switches to the battery / inverter as the backup source should the primary source fail.
When that happens, the transfer switch must operate to switch the load over to the battery / inverter backup power source (dashed path). The inverter only starts when the power fails, hence the name "Standby."
High efficiency, small size, and low cost are the main benefits of this design. With proper filter and surge circuitry,these systems can also provide adequate noise filtration and surge suppression.

 

3. Line Interactive

4. Double-conversion / online

5. Hybrid topology / Double conversion on demand

6. To be continue