Patent ID: 7456520
Filing Date: 2008-11-25
Classification: H02J,H02M

Abstract:
1. A control system for an uninterruptible power supply (UPS) for servicing a load, the UPS having a bypass feed path operable in parallel with an inverter feed path, the bypass feed path being engagable via a first switch to deliver a bypass current to the load, the inverter feed path having an inverter responsive to a control signal and being engagable via a second switch to deliver an inverter current to the load, the control system comprising: a processing circuit; and a storage medium, readable by the processing circuit, storing instructions for execution by the processing circuit for: in response to the presence of the paralleling detection signal, modifying the control signal to the inverter such that the inverter current is driven toward equaling the bypass current, thereby tending to cancel circulation current generated between the bypass feed path and the inverter feed path in response to the two paths operating to service the load in parallel.