Novel high frequency induction motor with single-phase rotor conductor and position sensor

Abstract

This paper presents a novel high frequency driven induction motor. Its rotor conductor structure, which has only single-phase winding, is different from the squirrel-cage rotor. Its single-phase short-circuit rotor windings exhibit different inductance distribution at different rotor position corresponding to stator winding. This phenomenon is similar with the reluctance machine. In order to start and operate the motor, position sensors are attached at the rear of motor to help the driver commutate the stator windings. In addition, a high frequency capacitor is connected between stator winding and driver to form a resonant loop. A phase-lock-loop circuit controls the output frequency of the driver so that the resonant current flows through stator winding is constant. It must be operated at high frequency over 10 KHz. Basic principle of the high frequency induction motor is introduced. Its operating principle and control are similar with the reluctance motor. The difference is that it produces repulsive force between rotor and stator poles but the reluctance motor is attractive. Compared with the traditional induction motor, it can reduce acoustic mechanical vibration by driving at near ultrasonic frequency range. A three-phase 12-poles prototype was implemented. Experimental results show that the practical usage of the theory.