Simultaneous propulsion and levitation control of linear induction motor in maglev system driven by power source with frequency component synchronous with motor speed

Linear Induction Motors (LIMs) are used to control the propulsion of maglev transportation and carrier system. In the usual maglev transportation system using LIM, the levitation of the carrier are controlled by the levitation magnets. It has problem that the controls of the LIM and of the levitation magnets interfere each other because the attractive force generated by the LIM affects the levitation control of the levitation magnets. We propose to use the attractive force generated by LIM in order to control the levitation instead of the attractive force generated by the levitation magnets. In this novel maglev carrier system, it is able to control thrust propulsion and levitation by only LIMs. We propose the control method of LIM by the two different frequency components to achieve the simultaneous and independent control of the propulsion and levitation. The thrust force of LIM is controlled by the drive frequency component. The attractive force is controlled by the frequency component synchronous with motor speed. It is able to design the controller more easily since the frequency components synchronous with motor speed cannot generate the thrust force. In this paper, we measure the dynamic characteristics of LIM and the controller is designed using the measured parameters of LIM. We use the experimental equipment of LIM with the disc-shaped secondary side. It is verified that both the propulsion and levitation control are achieved by the simulation and the experiment.