Transformer energization with low inrush current

Abstract

Systems and methods for reducing inrush current to energize a transformer from a first power source or second power source using a transfer switch device including monitoring input phase voltage at a first and second switching pair, sending a first set of gate signals to the first switching pair and second set of gate signals to the second switching pair to selectively couple the transformer to the first power source or second power source, and operating the first switching pair and second switching pair in a normal operating mode at a next cycle once transformer flux reaches a saturation point. The transfer switch device includes a first switch and second switch connected to the first power source and second power source, respectively, and each switch including the first switching pair and second switching pair connected in a reverse orientation to enable a bi-directional flow of current at each phase.