A field orientation scheme for current-fed induction motor drives based on the torque angle closed-loop control

A novel field orientation scheme for current-fed induction motor drives is presented. The scheme is based on the closed-loop control of the torque angle and has the merits of being simple in implementation and insensitive to rotor resistance variations. The limits of previous field orientation schemes are reviewed. The torque angle control scheme is then formulated, and its application to induction motor (IM) drives fed by either current source inverters or current-controlled PWM inverters is illustrated. As an example, a current source inverter induction motor drive incorporating the scheme is designed, and its performance, which has been tested by simulation, is given