Performance characteristics and design criteria for high-speed adjustable speed drivers for large turbomachines

Gearless-electric-motor adjustable-speed drives can, in many applications, be an attractive alternative to thermodynamic and hydraulic drivers on high-speed centrifugal pumps and compressors in the uppermost power range. The authors discuss electrical and mechanical design criteria for these synchronous motors as well as their limit ratings, provide actual examples of such machines, and highlight typical performance characteristics. A survey of the required auxiliary electrical equipment, identical to that used on low-speed load-commutated inverter (LCI) drives, and economic considerations are included