Medium- and high-voltage, low-speed drives using low-voltage IGBT converters

The paper describes the advantages of the brushless doubly-fed machine for medium- and high-power drives at low speed. It is shown that, without requiring a gearbox, a two-speed drive can be produced using a brushless machine controlled by a small, low-voltage converter. Thus, the converter can employ IGBTs instead of GTOs, which would otherwise be needed for 2130 V motors. The combination of low converter rating and simplicity should have substantial effects for the production of a low cost system to meet what is a troublesome operational requirement for alternative technology approaches.