Standby On-Line Hybrid

The Standby On-Line Hybrid is the topology used for most UPS under 10kVA (Volt-Ampere) that are labeled “on-line”. The standby converter from the battery is switched on when an AC power failure is detected, just like in a standby UPS. Additionally the small battery charger resembles a standby type UPS. This UPS will exhibit no transfer time during an AC power failure. The most misunderstood part about this topology is the belief that the primary power path is always “on-line,” when in fact the power path from the battery to the output is only half “on-line” (the inverter), while the other half (the DC to DC converter) is operated in the standby mode. This design is sometimes fitted with an additional transfer switch for bypass during a malfunction or overload.