The fundamentals of space‐vector theory

Space‐vector theory was developed to describe the transient behaviours of electric machines. In space‐vector theory, the spatial distribution of current linkages, fluxes and flux linkages, and voltages are presented with "space vectors". This chapter illustrates a special winding arrangement and the magnetic axes U, V, and W of a two‐pole three‐phase machine. This winding configuration is designed to produce a sinusoidal current linkage for each one of the three phases individually that when superposed still results in a sinusoidal flux density distribution across the air gap. The stator voltage vector for an alternating current (AC) machine consists of the resistive and inductive voltage components. Space‐vector modelling of the asynchronous machine can also be accomplished in the general reference frame. The space‐vector approach simplifies electric machine representation. Space vectors can be applied to the representation of all types of asymmetric or distorted three‐phase currents.