Six-phase cylindrical linear induction motor with high-frequency vibration suppression and experimental study

The six-phase cylindrical linear induction motor has been applied in many fields due to its symmetrical structure, high utilization of the primary winding and no transverse end effect. However, the inverter adopts the sinusoidal pulse width modulation (SPWM) strategy to power the motor, which causes the phase currents to generate harmonic currents at the switching frequency and its double or side-band frequencies, which in turn causes the motor to vibrate at high frequencies. To address the above problem, this paper investigates a carrier phase shifted control for suppressing high frequency vibrations in the six-phase cylindrical linear induction motor. In this paper, by staggering the carriers of the two sets three-phase windings by a certain angle and properly adjusting the carrier phase of two inverters in the motor system, certain side-band harmonics can be cancelled out by each other, which reduces the harmonic magnetomotive force in the air gap, and achieves the purpose of suppressing high frequency vibration of the motor. The simulation analysis and experimental results verify the correctness and effectiveness of the proposed control method.