Modular DC UPS systems for uninterruptible power supply

A wide variety of applications and fields of application, such as control technology, automation for Industry 4.0, motor drives and sensor technology, as well as camera and safety systems, industrial PCs or gateways, all require protection against system downtimes. This is provided by the uninterruptible DC power supply solution of the UPSI system, which is characterised by low total cost of ownership as well as high safety and durability due to the technologies used.

The UPSI series is available as an open-frame or DIN rail version and with two different separate energy storage systems:

• Maintenance-free supercaps for short and medium bridging times: Highly efficient and particularly durable with more than 500,000 charge and discharge cycles, charged and ready for use within a very short time. Energy storage units with supercaps impress with their high current carrying capacity, power density and reliability.

• Long-life lithium iron phosphate battery cells (LiFePO4) for longer bridging times: High energy density and increased safety as well as high cycle stability with 6,000 charge and discharge cycles. Including integrated high-performance battery management system (BMS), which monitors the complete charging and discharging process of each lithium-ion battery cell and ensures uniform charging of all cells.

A bidirectional converter (buck-boost) ensures very efficient and safe operation during the charging and discharging process of the connected energy packs. For the flexible use of different battery technologies, three charging methods with individual adjustment of the charging end voltage are implemented: Constant Current, Constant Voltage and Constant Power. The charging and control module is connected to the respective energy storage unit via two lines. This can even be replaced during operation (hot-swapping). The intelligent PowerSharing function ensures on the input side that the upstream AC/DC power supply does not have to be oversized.

To protect the cells, the charging MOSFET is deactivated after a defined time at the end of charging. The discharge MOSFET remains active so that discharging is possible at any time. In case of detected discharge (UPS operation after power failure), the previously deactivated charging MOSFET is immediately switched on again so that the current flow via the body diode only lasts a few microseconds and the charger returns to regular operating mode.

Monitors the output load to be supplied from the energy storage unit in backup mode (battery mode). If the load on the output falls below a certain limit, it is automatically disconnected from the charging and control unit so that it is not unnecessarily drained by the DC UPS electronics.

In PC-based control systems and computer systems, automatically initiates the restart of the PC system after a shutdown and when the supply voltage returns. In addition, the separate energy storage can be activated manually and thus the system can be started initially from the battery, e.g. for diagnostics.

USB and RS232 interfaces are available for data communication with controllers or PC-based systems. With the help of the HID battery parameter software, settings can be made conveniently on the DC UPS.

At Schukat electronic, in addition to the UPSI DC UPS systems with external energy storage units from Bicker Elektronik, we also offer systems with integrated energy storage in the form of supercaps and LiFePO4 battery cells as DIN rail variants.

In addition, our technical sales team is here to help with customer-specific questions about power supplies and more.