As the power shelf systems are paired to provide an additional fault-tolerant level of dc power support, additional diversity is realized. In this array, there are two power shelf systems each with multiple protective devices linked to load apparatus.
Dual power arrays will double the control and telemetry from an installation, as both systems contain communication ports. Each system will operate independently to transform ac to dc and distribute this support to the loads. Potentially, up to 4 ac input connections can be landed across the 2 power shelves to mitigate risk in losing utility main sources. Spreading the risk over a larger landscape is common within this type of fault-tolerant architecture.
Building on the diversified ac input structure, picture a power system, labeled ONE, with protective devices connected to the A input of load-X and load-Y utilizing individual circuits, then deploy power system, labeled TWO, with devices connected to the B input of load-X and load-Y. The four connections facilitate isolated and multiple paths for dc power support to the specialized apparatus. The A/B dc support path has now been established one diversified level into two power supply systems. The loss of a single power system should not dramatically effect operation.
It is possible to include additional load apparatus, J and K, into the architecture after current-draw analysis and sizing the power capacity of the system to meet actual demand.
While this illustration derives a primary source from utility ac mains, the identical architecture is being created with power systems hosting dc-to-dc power modules, instead of rectifiers. The common equipment deployment is a 130V dc input converter to a 48V dc output. The fault-tolerant overlay is utilizing the existing 130V storage system already installed and being maintained by the utility provider.
The historical 48V dc plant is being decommissioned and operational departments are consolidating critical power support on the 130v system, as reported by several clients. Watch for part three of this design series where the Hybrid blend of rectifiers and converters will be discussed.