Patent ID: 8754544

Claim:
An Intelligent Synchronization Module (ISM) for an Uninterruptible Power Supply (UPS) system for servicing a load, wherein the UPS system has a first UPS group having a first energy storage device, the first UPS group coupled to a first power source, and a second separate and independent UPS group having a second energy storage device, the second UPS group being coupled to a second power source, each of the first and second UPS groups having a master UPS, the ISM comprising: a processing circuit; and a storage medium, readable by the processing circuit, storing instructions for execution by the processing circuit for: determining one of the first UPS group and the second UPS group to be a master UPS group, wherein the determination of the master UPS group includes a determination of the availability and quality of said first power source and said second power source; assigning the other UPS group the role of a slave UPS group; and passing phase information relating to the master UPS group to the slave UPS group, thereby enabling the master UPS of the slave UPS group to effect synchronization with the master UPS group, wherein synchronization between the master UPS group and the slave UPS group is performed using a slow synchronization process and a fast synchronization process, wherein the slow synchronization process moves a frequency and a phase of the master UPS of the slave UPS group towards a frequency and phase of the master UPS group at a first rate, and wherein, when differences between the frequencies and phases of the slave UPS group and master UPS group are less than defined thresholds, the fast synchronization process is started and the frequency and the phase of the master UPS of the slave UPS group are moved until synchronous with the frequency and the phase of the master UPS of the master UPS group at a second rate that is greater than the first rate.