An Integrated 60 & 400 Hz UPS for Communications Computers

Abstract

A high efficiency and economical arrangement for providing power to computers with 400 Hz CPU requirements is introduced. The system utilizes a conventional 60 Hz static switching bypass type 60 Hz UPS connected to a common battery with a switching type redundant 400 Hz solid state UPS thus eliminating the double conversion losses and lower efficiency of an added rotary frequency converter. A method is provided for continuity of operation with failure of any major circuit components and means are provided for isolation and maintenance of any component without interrupting the load. The characteristics and circuit techniques of the inverters, rectifiers, and associated static switches are described and photographs of a 150 KVA 60 Hz and 75 KVA 400 Hz integrated systems are presented.