Basic Study on AC Motor Drive Using Rotating Magnetic Field Excited on LC Ladder Circuit

Abstract

　In three-phase AC motors, three-phase AC voltage system is essential to generate a rotating magnetic field. Three-phase AC motors also require a three-phase inverter for variable speed and torque operation. In general, the number of switching devices used in three-phase inverter is not less than six and decreasing its number is difficult. This paper focuses on an LC ladder circuit consisting of linear inductors and capacitors. This paper presents a new operating method of the AC motor based on a propagating magnetic field. It is successfully excited by connecting one single-phase AC power supply to the end of the LC ladder circuit. The induction motor operated by the presented method produces torque as in general induction motors.