dq WINDING REPRESENTATION
We studied in the previous chapter that the stator and the rotor flux
linkages
λs
a(t) and
λr
a(t) depend on the rotor angle θm because the
mutual inductances between the stator and the rotor windings are position
dependent. The main reason for the d- and q-axis analysis in
machines like the induction machines is to control them properly, for
example, using vector control principles. In most textbooks, this analysis
is discussed as a mathematical transformation called the Park’s transformation.
In this chapter, we will take a physical approach to this
transformation, which is much easier to visualize and arrive at identical
results