UPS Backup Power Supplies

Online double conversion backup power supply – power range 4 kW to 250 kW, short-term overload 2× rated current (higher on request). Energy passes through two conversions: from AC mains to DC (battery charging) and from DC back to AC for the output "artificial" grid supplying the backed-up equipment.

Pros:

• custom solution tailored to the customer's operation
• any grid failure (overvoltage, undervoltage, short circuit) will not cause downtime for backed-up devices
• guaranteed output voltage quality, very low voltage THD
• sinusoidal grid current, THD_i < 3 %
• adjustable grid-side power factor (0.9 inductive to 0.9 capacitive)

Limitations:

• higher price compared to the parallel solution
• inverter must be sized for the total continuous load including inrush currents

Backup power supply similar to the line interactive UPS type – power range 4 kW to 250 kW. The device performs only one energy conversion: from AC mains to DC for battery charging. During a mains failure the energy flow reverses – from battery through the inverter to the loads, with the grid disconnected after outage detection.

Pros:

• custom solution tailored to the customer's operation
• guaranteed supply voltage quality, very low voltage THD
• sinusoidal battery charging current, THD_i < 3 %
• peak-shaving – injecting additional power into the load to reduce peak grid consumption
• sized only to cover short-term outages
• lower price and higher overall efficiency compared to the series solution

Limitations:

• certain grid faults (large overvoltage, short circuit) may cause a short outage of the backed-up equipment (under 1 s)

Many applications require a backup solution to properly terminate the operation cycle during a power failure – typically electric trolleys, casting lines with melts, rolling mills or elevators. VONSCH UNIFREM frequency converters allow emergency operation with minimal backup energy requirements.

Elevator technology – concept of automatic emergency run of the cabin to the nearest floor during a mains failure. VONSCH has developed the optimised elevator backup supply UPS‑ZZ‑325 V, 230 V / 1500 – 3000 VA – it generates 325 V DC for the hoist drive inverter (motor 1 – 2.5 kW) and 230 V AC for the door drive, control system and brake (total up to 500 W).

UNIFREM drives implement a special function to detect the motion direction favoured by gravity (cabin vs. counterweight) – the motor can run in regenerative mode and move passengers to the nearest station with minimal battery energy demand.

For relevant VONSCH applications we offer the web portal VONSCH.CLOUD. From any browser you can see production, 15-minute trends, fault log and CSV export - no installation, bilingual (SK/EN).

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