A double-conversion online UPS ensures the highest level of power protection by continuously converting incoming AC power to DC and then back to AC. This process isolates connected equipment from power disturbances and provides clean, stable output at all times.
🔄 Step-by-Step Operation
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AC to DC Conversion (Rectifier Stage)
Incoming AC power—often affected by voltage sags, surges, or harmonics—is first converted into DC.
➤ This stage removes electrical noise and irregularities. -
DC Link with Energy Storage
The DC power is stabilized using capacitors in the DC link.
➤ These capacitors also store energy to bridge brief interruptions. -
DC to AC Conversion (Inverter Stage)
The clean DC is then converted back into tightly regulated AC power.
➤ The output frequency can differ from the input, offering flexibility for sensitive equipment. -
Battery Backup During Input Failure
If the AC input goes out of range or fails, the UPS instantly switches to battery power.
➤ The transition is seamless—capacitors in the DC link maintain continuous output without interruption.
📊 Suggested Visuals
To enhance understanding, consider adding:
- Block Diagram: Showing the flow from AC input → Rectifier → DC Link → Inverter → AC Output.
- Transition Illustration: Highlighting how the UPS switches to battery during input failure.
- Comparison Table: Double-conversion vs. line-interactive and offline UPS types.
Released for: Schneider Electric Thailand
