Various control schemes for indirect vector control of induction motor

This work mainly focus on controlling an induction motor similar to a D.C. Motor thereby eliminating the drawbacks like commutator, sparking at the brushes and gaining the features like robust construction, rigid in service etc. which are in built properties of induction motor by transferring the three stator current from a-b-c reference frame to d-q reference frame. In vector control the rotor flux angle is very crucial for decoupling of stator current. In indirect control the rotor speed is sensed by a speed opto coupler and the slip is calculated from mathematical expressions using rotor parameters and estimated rotor flux and speed. The slip speed when added to rotor speed yields the rotor flux speed , this rotor flux speed when integrated gives the flux angle which is very crucial to decouple the three phase sator current into d-q components. By controlling D- component the flux of induction motor can be controlled and by varying the Q component the torque component can be controlled hence a similar control to D.C. Motor is attained and induction motor now can replace the D.C.M motor in all such type of application.