What are the 3 Types of UPS System Available?

There are three types of uninterruptible power supply and they differ in the levels of power protection they provide and cost. The 3 types including Offline (standby) UPS, Line Interactive UPS and double-conversion Online UPS.

• Offline UPS: provide basic power protection and low-cost battery backup when mains power fails or fluctuates (flickers). They are the cheapest and smallest type of UPS system available, typically available up to 1kVA/1kW in size. When switching between mains and battery power there will be a millisecond (ms) break in output power and the output waveform is typically a stepwave or square-wave. The break and waveform are compatible with the type of power supply used in most electronic and computer-type loads (a switch mode power supply – SMPS) and the SMPS uses its electrical capacitance and own electrical characteristics to cover the break in power and waveform output. Typical formats are desktop and tower with internal batteries. Suitable for home PCs, security systems, retail terminals, gaming consoles, network peripherals, routers, switches and storage devices.
• Line Interactive UPS: are next level in power protection. The operating principle is similar to that of a standby UPS. The inverter section is active and in standby mode but switches quicker than a standby UPS and the output waveform may be a stepwave or sinewave. A sinewave is what we expect from the mains power supply itself. Line interactive therefore provide a cleaner output waveform and faster transfer to battery power. Line interactive UPS are the most commonly installed UPS up to 2kVA for IT loads. Typical formats are desktop, wallmount, tower and 19inch rackmount with internal batteries. Some models have battery extension pack options, for longer runtimes. Suitable for more powerful PCs, and file servers
• Online UPS: provide the ultimate power protection. This type of UPS is also referred to as a double (AC-DC-AC) or triple conversion (AC-DC-DC-AC) UPS. In an online UPS the inverter is always powering the load and draws power from a rectified mains power (or generator supply) converting this into the levels of DC power required to charge the battery and power the inverter. This is the AC-DC part of the UPS conversion technology. The inverter converts the DC to AC power; the second stage of the power conversion to give (in a double conversion UPS) the AC-DC-AC power output. Online UPS also feature an automatic bypass which routes the loads connected to the UPS output to the raw mains power supply if there is a UPS fault. Loads connected to Online UPS are fully protected from mains pollution through the double-conversion process and digitally generated sinewave output. As the inverter section is rated for continues running, online UPS can typically be installed with additional battery extension packs for longer runtimes. This type of UPS is the most commonly used in server rooms and data centres and is available in floor standing and 19inch rackmount formats from 500VA to several hundred kVA in single and 3phase configurations. Suitable for file servers and storage devices, complete local are network (LAN) power protection, server cabinets, server rooms, data centres, telecoms, hospital and industrial manufacturing processes