MODELING AND PERFORMANCE OF A 120-DEGREES SQUARE-WAVE INVERTER INDUCTION MACHINE DRIVE/

This paper extends and enhances prior work on the 120 degrees square-w ave inverter/induction motor drive to include short periods of regener ation produced by torque pulsations. Particular attention is paid to t he accurate calculation of the back e.m.f. of the open-circuited phase . A key feature of this work is the subdivision of the motor equations depending on the particular thyristors that are conducting. The above enhancements lead to improved accuracy (in the order of 20%) in the c alculation of motor torque over previously published work. Theoretical predictions are verified by previously published measurements on a si x-pole, three-phase, squirrel-cage induction motor producing a maximum motoring power of 185 kW.