Title :
Uninterruptible power supply systems in NTT
Author :
Yamashita, Hiroshi
Author_Institution :
NTT Network Syst. Dev. Center, Tokyo, Japan
Abstract :
A decentralized power system for an AC power system and a DC power system has been developed. In this system, the uninterruptible power supply (UPS) system is installed in telecommunications rooms, and is aimed at peripheral equipment in switching systems. This UPS system consists of 1 kVA add-on type inverter units, and has a maximum capacity of 5 kVA through parallel operation of 5 units. The inverter unit operates at a switching frequency of 25 kHz and weighs 14 kg per unit. The UPS system can supply the rated capacity of power even for equipment employing a rectifier circuit and a capacitor input filter. In addition, it can operate in both off-line mode and on-line mode. The UPS system can supply uninterruptible AC power even in the off-line mode. The author describes the configuration and the operation of the UPS system, and discusses the techniques for the off-line mode and high crest factor loads.<>
Keywords :
invertors; switching systems; uninterruptible power supplies; 1 kVA; 25 kHz; AC power system; DC power system; capacitor input filter; decentralized power system; high crest factor loads; inverter; parallel operation; rectifier circuit; switching frequency; switching systems; telecommunications rooms; uninterruptible power supply; Circuits; Computer peripherals; Power supplies; Power systems; Pulse width modulation converters; Pulse width modulation inverters; Rectifiers; Switches; Switching systems; Uninterruptible power systems;
Conference_Titel :
Telecommunications Energy Conference, 1990. INTELEC '90., 12th International
Conference_Location :
Orlando, FL, USA
DOI :
10.1109/INTLEC.1990.171279
