100 Amp Switched Mode Charging Rectifier for Three-Phase Mains

Uninterruptible power supply increases the availability of telecommunication systems decisively. Consisting of a large battery plant for 48 V or 60 V dc with a suitable charging rectifier, this fundamental power source maintains the secure operation of central offices or PBXes, independent of mains supply fluctuations. Considerable volume and cost are the well known disadvantages of such power systems. While the battery producers have been developing the new generation of sealed cells, designers of rectifiers have been investing remarkable efforts in reducing the size of large current range units. It is only the success on both fields that enables a reasonable integration of complete uninterruptible power supply within the communication system. The best way of avoiding the very large magnetic components used in SCR of ferro resonant controlled rectifiers, is to apply the switched mode technology. This paper is to present our latest achievements on the field of SM charging rectifiers for three-phase off-line operations. Power range up to over 8 kW and high efficiency of about 95 % will be discussed as the main features of the new power conversion system.