SYNCHRONOUS DRIVE PERFORMANCE OF BRUSHLESS DOUBLY-FED MOTORS

This paper presents recent studies of the steady-state performance of the brushless doubly-fed machine for adjustable-speed drive applicatio ns. The equivalent circuit and basic performance equations are present ed followed by a proven technique for the solution of the least restra ined form of the equations. Model predictions and experimental results are given. The studies show that the machine acts like both a synchro nous motor, with power factor adjustable by control winding excitation , and a slip-ring induction machine with slip power recovery and a low converter rating. The model is suitable for development of control sc hemes and performance index optimization.