Intelligent Universal Transformer



Enertronics is developing the Intelligent Universal Transformer (IUT) for use in utility applications. This work, currently funded by the Electric Power Research Institute (EPRI) is focused upon the development of a multilevel converter based electronic transformer to convert distribution voltage to household voltage. The system consists of a multilevel PFC converter, a multilevel DC/DC converter, and a high-efficiency DC/AC inverter.

The goal of the IUT is to use modular power electronics technology to replace the conventional copper-and-iron based bulky distribution transformer. The modularity allows flexibility should the user require a different voltage or power level.

System control is achieved by two separate DSPs for the front end and inverter that communicate via fiber optic. The IUT has been built and tested to show numerous advantages over conventional transformers. These advantages include:
(1) voltage sag ride through
(2) outage backup
(3) unity power factor even with nonlinear and lagging loads
(4) voltage regulation under overload and unbalanced load conditions
(5) clean output during utility capacitor switching
(6) over-current and short circuit protections, etc.