Online Double Conversion UPS (VFI – Voltage/Frequency Independent)
Online UPS consist of four key components; rectifier, batteries, inverter and a static switch. The rectifier converts incoming mains power in to stable DC voltage, which is used to charge the batteries. The stable DC voltage also supplies the inverter, where it is converted in to stable AC supply to power the critical load. This “double conversion” process creates a zero break transfer in the event of a mains failure, as the battery set is always connected to the inverter. The instantaneous switch between mains supply and battery power makes Online UPS the most comprehensive topology for protecting mission critical equipment.
Advantages
- Zero break transfer between mains supply and battery power
- Available for UPS applications above 5kVA
- Options for parallel and redundant systems
- Protection against all 9 major power anomalies
Disadvantages
- Most expensive topology under 5kVA
- Less efficient than VI Technology
