2.3 Squirrel Cage Induction Motor
2.3.1 Space Vector Representation
A three-phase AC machine may be described using the space vector method [1–9], as was shown by Kovacs and Racz . For this reason, the AC motor variables for a symmetrical machine fulfill the condition:
The summation of these variables gives the space vector:
Figure 2.8 shows the stator current complex space vector.
The space vector K may represent the motor variables (e.g. current, voltage, and flux). The vector control principle on AC machines takes advantages of transforming the variables from the physical three-phase ABC system to a stationary frame αβ, or rotating frame dq [3, 6].
Let us analyze, as an example, the stator sinusoidal currents transformation. The first transformation can be done to a stationary frame αβ (Clark ...