Rotary UPS – A power quality filter with high short circuit power.

As Rotary UPS systems, like the IEM Rotabloc ( are based on traditional alternator technologies with the technical capability of supplying the same high short circuit power as diesel generators the selectivity of protection devices can be achieved in a similar way as until now.

A Battery system still will be required to be able to offer sufficient Ride Through time for the PEM Fuel Cell System to provide power. As both solutions require an inverter technology to generate the AC power supply, the most adequate solution will be to design a Hybrid solution with a common inverter for both batteries and FC System.

In the by Powerpem Solutions provided scheme in fig.1, the IEM Rotabloc has a crucial role to stabilize the voltage, filter harmonics in both directions, supply short circuit power and provide sufficient ride through power to allow the battery system and/or FC System to supply the load.

The 10 seconds nominal autonomy time of the IEM Rotabloc will be, in developed countries with a stable and reliable grid, for more than 95% of the time capable to guarantee a reliable power supply to any critical facility.

The scheme as shown in fig. 1 is based on standard building blocks, readily available at this moment to design multi-MW datacenters. Further integration of the different technologies would improve CAPEX, OPEX and footprint of new Datacenter designs.


To fully replace internal combustion engine backup power, renewable technologies will need to continue to improve in terms of reliability, cost, and scalability. However, as technology continues to advance and the demand for sustainable backup power grows, renewable technologies are likely to become increasingly popular alternatives to traditional backup power sources.

By combining the benefits of both inverter-based technology and Rotary UPS solutions, it is possible to create a backup power system that is both reliable and efficient, with high levels of selectivity and protection for electrical equipment.