2N redundant power system and method using cross-coupled AC power transfer

摘要

A 2N redundant power system and method is disclosed that uses cross- coupled AC power transfer. Two cross-coupled AC Transfer switches always connect power converting hardware to an active AC source so that the 2N redundant power system prevents changes in the operating conditions when the loss of one AC source occurs. The system includes a first power source for providing power to a load through a first branch, a second power source for providing power to the load through a second branch and a pair of AC transfer switches cross-coupling the first power source to the second branch when a failure to the second power source is detected, and vice versa. A first and second contactor arrangement each include a first contactor and a second contactor connected in series. A control circuit includes a first coil system for controlling the first contactor arrangement, a second coil system for controlling the second contactor arrangement, and a coil system selection circuit. The coil system selection circuit includes a relay system for connecting the first or second coil system to ground to activate either the first or the second coil system, and a primary source failure detection circuit for detecting a failure of the primary power source and activating the second coil system in response thereto. The primary source failure detection circuit further includes a connection deriving power from the primary power source, a delay circuit for delaying a failure identification signal, and a relay coil system for receiving the failure activation signal to activate the second coil system.