Comparison between transformer-based Vs. transformer-less UPS systems

With the advancement and development of power electronic components, especially the IGBT (Insulated Gate Bipolar Transistor), transformer-less UPS systems are starting to be widely used for UPS size 300 KVA and less in lieu of the conventional transformer-based online UPS systems. Selecting a transformer-based or transformer-less UPS might not be simple choice at it seems. Many factors must be taken into consideration, where size, efficiency and reliability are the first to think about, there are far more factors to consider before making a decision. This paper will address the different factors that must be studied before selecting your UPS.