An uninterruptible power supply (UPS) provides backup power for electrical equipment, production facilities, control centers, hospitals, etc. in the event of power failures such as power outages, micro-interruptions or voltage dips. These disruptions are a sensitive issue in many sectors, as system failures are possible and they sometimes cause enormous economic damage.

As a rule, battery-based solutions, rotating systems with flywheels or ultracapacitors are used for intermediate energy storage. UPS technologies differ, sometimes considerably, in the areas of application and in the level of acquisition and operating costs.

Battery-based UPS systems are often used in a decentralized manner to protect individual production lines. They are inexpensive, but are subject to aging over time with decreasing reliability. For this reason, the batteries have to be replaced after just a few years.

Rotating UPS systems are suitable for centralized protection of complete systems due to higher power ratings and a long service life. However, the investment costs are high. Further costs arise from the required performance of annual maintenance and the regular replacement of wear parts.

The UPS system based on ultracapacitors is specially designed for bridging short voltage dips of up to 10 seconds in low-voltage and medium-voltage networks and offers particularly economical use here. Compared to the other UPS solutions, the acquisition, energy and operating costs here are low while maintaining high efficiency and low losses.