One of the current debates in the data center is over the best uninterruptible power supply (UPS) design to use: transformer-based or transformer-free. As in most debates, the sides have been drawn and the arguments focus on technology. While an understanding of the technology is important, the focus should instead be on the particular application in question.
There is growing interest in using transformer-free UPS modules in higher power, three-phase, mission-critical power backup applications (e.g., 200 kW to 5 MW). However, many organizations are unclear about which architecture — transformer-based or transformer-free — is best suited for a particular application. Regardless, having the option is desirable. According to the Uptime Institute’s 2012 Data Center Industry Survey, a third of large companies and nearly a quarter of small companies will deploy smaller floor plans and modular components in data centers in the next 12 months. If so, more flexible, smaller footprint UPS units will be desirable.