ABSTRACT
The topic of Uninterruptible Power Supply has been addressed. Most industrial standards require a fast connection of the AC grid supply in order to allow an uninterrupted operation of computing and communication equipment. A series of possible situations are identified to jeopardize the quality of energy supply. The conditioning of the energy supply can be done with passive or active solutions. The Uninterruptible Power Supply systems have the role to deliver energy to load when the grid voltage fails. Several topologies can be used: Uninterruptible power supply, in standby state (of type, Standby UPS); Uninterruptible power supply, in direct connection with the grid (Line Interactive UPS); Uninterruptible power supply, with ferro-transformer (de tip Standby-Ferro UPS); Uninterruptible power supply, with double conversion (Double Conversion On-Line UPS); Uninterruptible power supply, with delta conversion (Delta Conversion On-Line UPS). The energy is stored in rechargeable batteries, high-capacity ultra-capacitors, or by other storage methods. Storage energy topic is very important and brief information is provided herein. The status of the UPS systems is monitored with special systems for communication and management, such as SNMP and HTTP. Modern systems expand the traditional use of UPS systems to power conditioning or power shaving functions. Their meaning has been explained in this Chapter.
