A system is provided. The system includes a plurality of uninterruptible power supplies (UPSs), a ring bus, at least one load electrically coupled to the plurality of UPSs and the ring bus, and a controller communicatively coupled to the plurality of UPSs. The controller is configured to calculate an output voltage frequency for each UPS of the plurality of UPSs, and control operation of each UPS based on the respective calculated output voltage frequencies.