It's time to rethink your data center design
While many are familiar with "Catcher architecture" or "redundant block architecture," few have put this model through its paces, although that's about to change.
Today's Data Centers are loaded with challenges – constantly working to provide maximum availability in the face of burgeoning demand, whilst offering continuous service and striving to provide reliability and sustainability. These factors have become the performance baseline for every hardworking facility, all seeking significant savings in terms of CAPEX and OPEX for optimized electrical distribution – to be underpinned by the highest possible levels of resilience.
So how does architectural resiliency impact availability, and can intelligent design help solve some of the more troublesome challenges faced by Data Centres with an eye on their future performance?
Optimizing Data Center design with block redundant architecture distribution
Considering architecture strategy from a design perspective, providing continuous, reliable service and eliminating downtime is key – with availability rooted in architectural resiliency and optimizing TCO. Looking further ahead, CAPEX and OPEX are critical, but so is carbon footprint – all of which are impacted by architectural choices. Similarly, how straightforward it is to maintain a facility will also be affected by early design decisions – as ongoing maintenance can become unnecessarily complex due to unwise moves concerning electrical distribution architecture.
Resiliency has become a watchword for design – particularly in embracing modular solutions and sizing for a facility's needs today, but with the ability to scale and flex over time. Specific designs will minimize the need for redundant hardware and optimize resource utilization – leading to the installation of less equipment, lower capital costs, and a reduced carbon footprint while simplifying maintenance.
One such architecture, Catcher, ticks every box.
How does Catcher fit with typical UPS topologies?
With traditional 2N redundancy, a Data Center has twice the necessary quantity of each critical component to ensure that no single point of failure can disrupt the overall operation. Even during a component failure, the system continues to operate without interruption for exceptional reliability.
To provide this assurance in the event of unplanned maintenance or unexpected faults, the electrical design needs all the electrical equipment – generators, inverters, UPS, switches – to be redundant, which means investing in twice as much equipment and requiring twice as much space.
Architectures are now evolving to reduce the initial CAPEX by ensuring a high level of redundancy via distributed redundancy or Catcher architecture.
Distributed architectures – such as 4N3 and 5N4 – optimize power redundancy by sharing it between different systems.
There is a degree of complexity, however, as the power distribution to IT racks uses a different bus bar per power stream, which can be costly and complicate maintenance processes.
Taking the example of 4N3 architecture, the four systems can work at up to 75% capacity in regular operation, and in the event of one supply being lost, the three remaining can continue to supply the IT load.
Using block redundant – Catcher – architecture to reduce cost and increase resilience
The Catcher architecture effectively allows the end user to choose the redundancy level required to optimize CAPEX while maintaining fault tolerance and the possibility of simultaneous maintenance. For example, an architecture might comprise six regular power streams that can be loaded up to 100%, thereby optimizing the usage rate of a Data Center and 1 or 2 redundant power streams – ready to take the load in case of one or two failures.
The use of static transfer systems (STS) placed between the UPS and the load means that the critical load can be transferred from the "normal path" to the redundant path, which will "catch" online, providing a continuous power supply without disruption to the critical load.
"In typical operation, loads are supplied by the usual path. In the case of any problems or maintenance on the usual path, the STS will automatically transfer the load to the redundant path. This block redundant architecture philosophy seamlessly transfers from the normal path to the Catcher.
Another option with Catcher is the combination of a Static Transfer Switch and an Automatic Transfer Switch. For example, one side of the IT customer's load (side A) is connected to the STS, and the other (side B) is connected to the ATS – each is connected to typical and redundant paths.
In normal path failure, the STS will switch first, bringing in redundant blocks, and the ATS will follow, ensuring a seamless and simultaneous transition for the two paths. In conclusion, the A and B sides of the IT racks will stay supplied, keeping the servers redundant."
Optimized electrical infrastructure with better TCO & greater sustainability.
When calculating CAPEX and OPEX benefits for Data Centers, the complete electrical infrastructure should be considered - from the high-voltage transformer to the IT load. Choosing the proper redundancy (1 redundant block for X normal blocks) will generate significant savings in CAPEX and OPEX versus a traditional architecture. For instance, a full power stream could be removed, including a transformer, a genset, the distribution board, a UPS, the batteries, and all the associated maintenance operations.
"When you scale up to 10 data halls, for example, although STS equipment is required to connect the redundant block, it's still less equipment overall: fewer transformers and gensets, fewer UPS, batteries – up to 30% less equipment. For example, when we compare a one STS Catcher architecture versus a 2N design, we see a global CAPEX reduction of 42% and a reduction in footprint of 38%. The result is a highly optimized electrical infrastructure, enhanced TCO, and greater sustainability, which makes it a compelling solution for colocation Data Centers."
Validated in the factory and proven in the market, prominent players in key Data Center applications have put these systems to the test, and the list of success stories continues to grow worldwide.
"The Catcher model can optimize redundancy while limiting investment costs. Being highly flexible, it is the ideal solution for adapting to the particular and evolving needs of Data Centers – empowering designers to create better Data Centers and making it time to rethink their designs to ensure they're fit for the future. And having been successfully installed in the field for several years, several hundred MW of Catcher have proven the high reliability of STS products in demanding operating environments."
Manufacturer product compatibility proven
Finally and importantly, product compatibility is vital in terms of UPS and STS; by ensuring that equipment works together in harmony and with similar parameters, it's possible to address any network or IT load variation.
"The full UPS + STS package from Socomec masters this Catcher architecture, ensuring complete compatibility under any operating conditions – including sudden variation in voltage, UPS high-efficiency mode transition, and voltage drops.
If you would like to discuss this architecture further, please get in touch with us.