High Performance Control of AC Drives with Matlab / Simulink Models

5.3 DTC of Induction Motor with Ideal Constant Machine Model

5.3.1 Ideal Constant Parameter Model of Induction Motors

5.3.1.1 Induction Machine's Dynamic Model in dq Rotating Reference Frame

An induction machine with a perfectly smoothed air gap is considered. The phase windings of the machine are assumed to be physically 120 degrees apart for both stator and rotor. Winding resistances and leakage inductances are assumed to be constant. All the parasitic phenomena, such as iron loss and main flux saturation, are ignored at this stage. The induction machine under consideration is therefore an ideal smooth air-gap machine with a sinusoidal distribution of windings, and all the effects of MMF harmonics are neglected [13, 14]. A schematic representation of the machine is shown in Figure 5.6.

Figure 5.6 Schematic representation of induction machine with reference frames in three-phase domain and common rotating d-q reference frame

The notations in the figure above are:

1. : angular rotor speed;

2. : angular speed of stator flux space vector;

3. : instantaneous rotor angular position with ...