Fault isolation within power distribution systems

Faults originating in one equipment group may be coupled into other equipment groups. A coupling mechanism appears as impedances in the power distribution system which are common to several equipment groups. The authors demonstrate that the effect of these impedances can be controlled using local energy sources. A detailed lumped-constant model of a typical telecommunications power distribution system and a SPICE-based computer analysis are used to estimate the short-circuit induced voltage transients. In addition, results from a laboratory model of the system are used to validate the computer model and provide additional insights into the problem. The authors conclude that fuse operating time is not a critical parameter in the design of fault tolerant systems