Views: 0 Author: Site Editor Publish Time: 2024-02-07 Origin: Site
In an conventional UPS configuration with N+1 configuration, where N=2, we put in place a parallel configuration with 3 UPSs in parallel and an common output from the parallel bus is taken and provided as a input to the critical loads.
Although this configuration provides the redundancy at UPS level, there is still a possibility of a single point of failure, which is the common parallel bus (a rarest scenario).
Disadvantages of the configuration includes
o Concurrent maintenance is not possible
o Critical parallel bus is not a fault tolerant design, should there be fault generated down stream, the same can be propagated to the critical bus impacting the availability for other critical loads.
o Single point of failure in parallel bus
These above mentioned disadvantages can be overcome by optimising the system design using an STS and the common parallel bus is replaced with a three independent STS with a criss-cross connection as shown in the below table.
This configuration helps us to have
a concurrent maintenance of the distribution system as the UPS can be removed without disturbing the load.
compartmentalisation of fault in the downstream distribution of the load is possible as the STS doesn’t allow the fault to transfer(example a fault in load connected to static switch C, will impact only the loads connected to that specific static switch).
no single point of failure as we migrate to multiple N configurations instead of conventional N+1 configuration.