In the control of any power electronics drive system (say a motor);to start with, a mathematical model of the plant is required. This mathematical model is required further to design any type of controller to control the process of the plant. The mathematical model can be obtained by various methods, viz., from first principles, system identification methods, etc. This mathematical model may be a linear / non-linear differential equation or a transfer function (in s or z-domain) or in state space form. In this section, we present the mathematical model of the induction motor. The mathematical model of the SCIM system used in our work consists of space vector PWM voltage source inverter,
induction motor, direct flux and the torque control [56]. The drawback of the coupling effect in the control of SCIMs is that, it gives sluggish response and the system is easily prone to instability because of a high-order system effect. This problem can be solved by making use of either vector control or field-oriented control. When this type of control strategy is adopted, it can make an induction motor to be controlled like a separately excited DC motor. Of course, the control of AC drives can exhibit better performance. Thus, due to the above mentioned reasons, an
induction motor model was established using a rotating (d, q)field reference (without saturation) concept [56]. The power circuit of the 3- induction motor is shown in the Fig. 1.
Fig. 1 : Power circuit connection diagram for the IM