The two main types of UPS systems are transformer-based and transformer-less UPS. Transformer-based UPS systems use a transformer to boost AC voltage levels, provide galvanic isolation, and offer robust power conditioning. They are larger and heavier due to the presence of the isolation transformer and are commonly used in applications that demand high fault tolerance, such as industrial facilities and large data centers.
On the other hand, transformer-less UPS systems do not require a step-up transformer after the inverter. They are more energy-efficient, compact, and produce lower harmonic distortion levels. They are commonly used in applications where space is limited, such as small offices and data centers.
When choosing between a transformer-based and transformer-less UPS system, consider factors such as equipment criticality, power quality requirements, load capacity, available space, and budget to make an informed decision that meets your specific needs.
What Are The Advantages Of Transformer-Based UPS?
There are two main benefits of a transformer-based UPS. They are more robust and therefore have less points of failure. The transformer provides galvanic isolation, a separation of the input and output supplies, protecting the load from any spikes, surges, or electrical noise.
Transformer-based UPS’s are usually used for 100 kVA and above and the choice to achieve large kW sizes or provide redundancy.
Benefits of Transformer-based UPS:
- Galvanic isolation
- Independent mains power supplies
- Dual load protection from DC voltage
- Providing a higher phase-neutral inverter short circuit current than a phase-phase short circuit current
- Superior power protection when presented with power quality problems
- Greater robustness with respect to back feed protection
- Physical: reduced size and weight (a factor for space-restricted data centres)
- Operational: higher energy efficiency (particularly at lower loads), lower noise levels, and less heat
- Cost: lower purchase, installation, and running costs (i.e. needs less air conditioning)
Another issue with transformer-less UPS power supplies is their power strength limitations. To achieve larger kW size or redundancy, several transformer-free UPS modules need to be paralleled together – the more modules (and components), the greater the likelihood of failure.