PROJECT TITLE:

Bumpless Automatic Transfer for a Switched-Doubly-Fed-Machine Propulsion Drive - 2015

ABSTRACT:

Variable-speed drives (VSDs) combined with doubly-fed machines (DFMs) supply interesting flexibility for power electronic drive style. These also give opportunities for controlling interactions with an ac grid. Style options are most versatile for the VSD DFM when the machine stator will be operated from an ac or a dc source, selected as appropriate. This paper presents a silicon-controlled rectifier (SCR)-based mostly transfer switch that may connect the stator of the DFM either to an ac source or a dc source “on-the-fly.” Current commutations of the SCRs and a “bumpless” transition in shaft behavior are both controlled from the rotor. Experimental results demonstrate wide-speed-range and four-quadrant operation of the drive achieved with a rotor converter rating that is one third of the DFM power rating.