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ITGlossary · UPS technology
Transformerless UPS
Modern UPS design that omits bulky transformers to improve efficiency and reduce size.
Technical level:Advanced
Transformer-less UPS units use high-frequency power electronics (usually IGBTs) to regulate the voltage, without the heavy low-frequency transformer. Today this is the most widespread design in double-conversion UPS units, from small single-phase models up to large three-phase and modular systems.
The benefits are higher efficiency, especially in larger units, lower weight and size, and less heat. This reduces energy and cooling costs over the whole life of the unit.
Because there is no galvanic isolation, correct earthing and neutral connection are particularly important. If the load requires isolation, an external isolation transformer can be added.
Related terms
- Offline (Standby) UPSA UPS that leaves the load on the mains and switches to battery only when the mains fails, with a short transfer time; the simplest and cheapest topology.
- Static BypassAn electronic path inside the UPS that instantly and automatically transfers the load to the mains on overload or internal fault.
- TransformerAn electrical component that changes voltage levels or isolates circuits.
- Transformer-Based UPSTraditional UPS design using internal transformers to regulate voltage and provide isolation.
- Serial PortA communication port on a UPS used to connect and transmit signals to computers or monitoring equipment.
- Double Conversion EfficiencyThe share of input power that an online UPS delivers to its output, lower at light load and highest at medium to high load.