An uninterruptible power supply (UPS) ensures the backup power supply of electrical equipment, production facilities, control centers, hospitals, and other critical infrastructure in the event of grid disturbances such as power outages, microinterruptions, or voltage sags. These disruptions are a sensitive issue in many sectors, as system failures are possible and they sometimes cause enormous economic damage.

UPS systems are responsible for the smooth and safe power supply of devices, plants and industries. They are considered a modern safety system that protects against power outages and power fluctuations in the form of overvoltage or undervoltage. The UPS systems continuously monitor the incoming voltage from the mains connection. As soon as a fault occurs, the systems switch to emergency power supply within a few milliseconds.

In most cases, battery-based solutions, rotary 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 specifically designed to bridge short voltage sags of up to 10 seconds in low-voltage and medium-voltage grids, offering a particularly cost-effective solution for this application. Compared to the other UPS solutions, the acquisition, energy and operating costs here are low while maintaining high efficiency and low losses.