What does redundancy mean in the context of power supplies?

The reliability and availability of the DC voltage can be increased with the help of a redundant system. To create a redundant system, an additional power supply must be installed in reserve. This power supply then provides the necessary load current if another power supply in the system fails. 

The individual power supplies must be decoupled using redundancy modules to prevent a faulty power supply (e.g. a short circuit in the output diode) becoming a load on the functioning power supplies. If this happens, the output voltage can no longer be guaranteed.

Generally, two identical power supplies are connected in a 1+1 configuration. In more powerful systems, an N+1 configuration is also possible. For example, if a current of 100 A is needed, six 20 A power supplies can be connected in a redundant system. If one power supply fails, five others with a total current of 100 A are still available.

Each power supply must be fitted with its own input fuse. Redundant systems require careful monitoring to allow a maintenance request to be triggered in the event of a device failing. The DC-OK signal of the power supplies can be used for this purpose.