Design considerations for powering 415 Hz computer systems

It is noted that the design of 415 Hz power systems for mainframe computer systems requires additional considerations beyond those of conventional 60 Hz systems. The effects of the higher frequency on the wiring, components, and power system design are explored. Voltage drop, line drop compensation, centralized versus distributed power sources, and the special requirements of typical mainframe computer systems are considered. The power quality requirements of 415 Hz computer systems are significantly different from those of 60 Hz computer systems. The steady-state voltage tolerance is generally much tighter while the frequency tolerance is much broader. Because of the effects of the higher frequency on wiring impedance, 415 Hz wiring practices are different from those for a 60 Hz system. Nonmetallic or nonferrous wireways and relatively short wiring runs are recommended. Wire sizes larger than #2/0 are not effective at reducing wiring voltage drop, parallel conductors in parallel conduits are recommended. For best results, multiconductor cable assemblies such as the seven-conductor 400 Hz cable are recommended. Both passive and active line drop compensation techniques are available to help offset wiring voltage drop. Centralized 415 Hz power sources offer the advantages of economies of scale and ease of redundancy, which having the disadvantages of complicated 415 Hz wiring system design, higher installation costs, lack of flexibility, and potential load interactions. Distributed 415 Hz power sources minimize 415 Hz wiring and make it easier to meet the computer system's power requirements