Different Types of Uninterruptible Power Supply

At Advanced Power Technology we have over three decades of experience in providing businesses and organisations with a range of complete backup power solutions to suit all requirements. Uninterruptible power supply (UPS) systems are designed to provide emergency power to a load when the system senses that the electrical power input has failed. However, UPS systems are different from standby generators or emergency power systems in that they provide instant protection from power failure by switching to battery backup.

Installing a UPS system will keep the power flowing, protect data centres and ensure your business runs efficiently and smoothly. Here’s an overview of the different types of UPS systems available:

• Stand by UPS systems: this type of UPS system is the lowest in cost without having to compromise on efficiency. In the event of a power outage, stand by systems work by transferring from battery power to back up power using the transfer switch. The majority of standby UPS systems include a surge protector, with a power quality filter on the on the incoming line. Stand by UPS systems are ideal for providing light surge power protection.
• Line Interactive: Line interactive UPS have a battery-to-AC power converter which is always connected to the UPS’ output. When the inverter is operated in reverse during periods when the input AC power is normal charges the battery. In the event of a power failure, the transfer switch opens, allowing power to flow from the battery to the UPS output. This type of UPS system provides additional filtering whilst reducing switching times (in comparison to standard UPS topology) as the inverter is always on and connected to the output.
• Double conversion: The design of double conversion UP systems enables power to flow into the rectiver. When in the rectifier, the power is converted to DC power and a tiny amount of this DC current is used to charge the batteries. The remaining power is converted back to AC via the inverter to support the load and this is where the name ‘double conversion’ comes from. If a power failure occurs, double conversion systems draw DC power from the batteries, via the converter, to provide power to the critical load. This type of UPS design eradicates any transfer time because the inverter is already fully engaged and giving support to the load. Although double conversion UPS aren’t as efficient as other options, they do provide the most effective isolation for critical load from power quality issues.