Symmetrical GTO current source inverter for wide speed range control of 2300 to 4160 volt, 350 to 7000 hp, induction motors

A line of variable-speed 2300-4160 V, 350-7000 hp induction-motor drives for either fan or constant torque load applications is described. The drives are current-sourced, consisting of one or two six-pulse thyristor phase-controlled source converters in series, a DC link reactor, a six-pulse, symmetric-GTO (gate-turn-off), load inverter, a three-phase load capacitor in parallel with the induction motor. The drive features a wide speed range of operation, high inverter efficiency, and good motor current and voltage waveshape over the speed range. >