A simple understanding of field-orientation for AC motor control

In the AC motor control field, “vector” has now become a grossly abused term causing confusion e.g. as to whether it signifies an alternative to pulse-width-modulation (i.e. DC-to-AC power conversion) or a technique for AC motor torque control. To emphasise the latter meaning, the term “flux-vector control” is now widely accepted, but the confusion still continues with phrases like `sensorless flux-vector control´. Hence, the term “field-orientation” is used here in an attempt to provide a simple understanding of field-orientation for AC motor control