Patent ID: 8223515

Claim:
An apparatus comprising: a transformer module for a medium voltage drive, the transformer module including: a main primary winding coupled to a first input power source to receive a medium voltage signal therefrom; a plurality of main secondary windings each to couple to a power cell of the medium voltage drive; and an auxiliary primary winding coupled to a second input power source to receive a low voltage signal therefrom, wherein the auxiliary primary winding is spatially separated from the main primary winding and the plurality of main secondary windings; and a cabinet coupled to the transformer module to provide the medium voltage signal and the low voltage signal to the transformer module, wherein the cabinet includes a control circuit to provide the low voltage signal to the transformer module on power up of the medium voltage drive and after a predetermined time or a command signal to switch off the low voltage signal to provide the medium voltage signal to the medium voltage drive, wherein the control circuit is to switch the low voltage signal to the medium voltage drive when a loss of the medium voltage signal is detected during operation of the medium voltage drive.