Wireless UPS Paralleling
Staff -- Consulting-Specifying Engineer, 6/1/2002
Powerware, Raleigh, N.C., offers Powerware Hot Sync, a patented paralleling technology that is said to eliminate system-level single-point-of-failure, enabling UPS modules to work in parallel and complete synchronization, for both redundant and capacity systems. The system features two identical modules arranged in a parallel redundant configuration and a parallel tie cabinet connecting the modules to the critical bus. A common bypass input source allows the modules to synchronize their outputs, even when one or both of the parallel cabinet MOBs are open for maintenance.
The significance of this technology is that it overcomes the primary conundrum that has faced power technology engineers: how to parallel UPS modules to provide N+1, N+2 or higher redundancy without introducing a single-point-of-failure. By eliminating the communication wires between the UPS modules, and employing an algorithm by which each UPS constantly checks its own output for any variation on the critical bus, each UPS operates independently, but in complete synchronization with the other UPS in the system. The result of this operation is that the UPS modules automatically share the critical load, and can selectively trip and remove themselves from the critical bus if inverter failure or some other critical event occurs.
From Pure Power, Summer 2002.
