Control system, method and product for uninterruptible power supply

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 configured for facilitating:

• the generation of a paralleling detection signal indicative of the bypass feed path operating to service the load in parallel with the inverter feed path;
• and
• in response to the presence of the paralleling detection signal, the modification of the control signal to the inverter such as to drive toward equalization the bypass current and the inverter 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.

A computer program product for controlling 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 computer program product having machine readable instructions embodied in a tangible medium for:

• generating a paralleling detection signal indicative of the bypass feed path operating to service the load in parallel with the inverter feed path;
• and
• in response to the presence of the paralleling detection signal, modifying the control signal to the inverter such as to drive toward equalization the bypass current and the inverter 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.

A method for controlling 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 method comprising:

• generating a paralleling detection signal indicative of the bypass feed path operating to service the load in parallel with the inverter feed path;
• and
• in response to the presence of the paralleling detection signal, modifying the control signal to the inverter such as to drive toward equalization the bypass current and the inverter 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.