BRUSHLESS INDUCTION SYNCHRONOUS MOTOR WITH TWO STATORS

摘要

Rotor windings 33 and 34 are recommended for the two salient rotor cores 31 and 32, respectively, and the rotor windings on the salient poles adjacent to each other on the axis are connected in series with each other. The diodes 35 are connected in parallel between the series connection points. On the outer circumference of the two salient pole cores, a plurality of rotor conductors 36 and 37 are mounted in communication. In opposition to the two salient pole cores, two stators 21 and 22 and two direct current excitation windings 41 and 42 are provided. The number of poles of the stator is equal to the number of poles of the salient rotor core, while the number of poles of the DC excitation winding is different from the number of poles of the salient rotor core. One of the two stators is provided with a voltage abnormality device 25 for selectively generating a phase difference of 0 ° and 180 ° between two rotor fields generated around two salient pole cores. Start-up and acceleration are performed on the principle of an induction motor with the phase difference of the voltage abnormality device being 0 degrees. When the rotational speed is close to the synchronous speed, the phase difference of the voltage abnormality device is set to 180 ° and a DC excitation winding is applied to the synchronous operation. The alternating voltage induced in the rotor winding by the stationary magnetic field by the DC excitation winding is rectified by the diode to form a magnetic pole in the two salient rotor cores. Since starting is performed on the principle of the conventional induction motor, starting torque is large, and thus no special starting device is required. In addition, at the synchronous speed, the rotor winding acts as a field winding, so the synchronous torque is large and no maintenance such as a brush is required.