Data Center Isolated Parallel Ring Bus Differential Protection Scheme

UPSs are used in data centers and other critical power applications for power conditioning and back-up. In addition, to ensure reliability of the data center, a redundant architecture is needed. This increases capital expenses and decreases the utilization rate. One approach is to use the isolated parallel ring bus (IPRB) architecture with static UPS. This features load sharing with active and reactive power transferred through choke inductors to the ring bus. This architecture maximizes the utilization rate while maintaining the reliability of the system. The protection scheme in this IPRB is critical to guarantee the operation in case of any fault. In this paper, the differential protection scheme of the IPRB is explained with simulation and field-testing results. The differential protection can effectively identify and isolate faults to ensure uninterrupted service to the load.