Investigations into optimum design rules for new brushless doubly-fed induction generator: Rotary converter generation system I

A different topology for brushless doubly-fed induction generators is presented. A power conditioning system is mounted onto two coaxially connected wound rotors. Carbon brushes and slip rings are replaced by the wound rotors and the rotor-mounted power condition system, which bi-directionally exchanges power to the grid with appropriate amplitude and phase difference between the voltages applied to the stator and the rotor for slip operation. The relation of power generated by two wound rotating machines for slip operation is derived as a function of the ratio of the number of poles from the voltage equations of induction machines in this paper. Analysis of the power of the two machines in slip operation revealed optimum design rules for the brushless doubly-fed induction generators to minimize the total rated power of the machines.