Abstract:
This paper discusses the steady state maximum and minimum torque outputs and the operation at
unity power factor of the doubly fed twin stator induction machine and the doubly fed induction
machine using equations with analytical solutions. Speeds above and below the natural or
synchronous speed are discussed. The results of simulations, based on a laboratory machine
comprising two nominally identical wound rotor induction machines, are presented. It is shown
that the maximum torque for the doubly fed machine is independent of speed and for the doubly
fed twin stator induction machine there are variable maxima and minima dependent on speed.
