VECTOR CONTROL OF INDUCTION MOTOR BY A

                         CONTENTS

 Introduction

1.Traditional nine level inverter

2.Cascaded  31-level inverter with high power quality

3.Experimental setup

4.Switching pattern

5.Harmonic analysis

6.Simulation of  31-level inverter

Algorithm flowchart

“c” program

simulation results           

7.Experimental verification

8.Conclusions

           

List  Of  Symbols

 : Leakage inductance of phase a

 : Resistance of phase a

 :  Leakage inductance of phase r

R₂  :   Resistence of phase r

M_rs :   Maximum value of mutual inductance between stator and rotor windings

q  :    w_mt

P  :    pair pole number

J   :    Total constant mechanical inertia

f_r   :    Total friction coefficient s

T_r  :     Resistance torque

W_r  :     Mechanical speed

T_em :     Electromagnetic torque(N.m)

j₀   :    Air-gap flux(Wb)

j_0ref  :   Air-gap flux of reference(Wb)

T_emref  :  Electromagnetic torque of reference(N.m)

                        ABSTRACT

AC motors, whilst being very economical, rugged and reliable due to the absence of commutators and brushes, have inherently poor dynamic behavior. However, the dynamic behavior can be made to match that of an equivalent separately excited DC motor using Field Orientated or Vector Control.In this project vector control of induction machine by a spiral vector theory is proposed. This method permits to establish the performance equations of the induction machine in function only one phase variables of the stator and rotor.   The obtained equations are basically using in field oriented control. The   simulation results give a good decoupling between the air gap flux and electromagnetic torque and it sufficient to track one voltage quantities   or current to make the regulation in the case of a direct vector control of induction machine.