Control of Traction and Levitation of Linear Induction Motor Driven by Power Source With Frequency Component Synchronous With the Motor Speed

Linear Induction Motor (LIM) has many applications. The maglev transportation system is the most popular application. The typical maglev transportation system has the traction system and levitation system separately. The LIM is used for the traction system. The levitation magnets are implemented as the levitation system. We have developed a novel maglev system using the LIM without the levitation components. In this system, the attractive force of the LIM can be used for the levitation control. In this paper, we propose the novel control method of the thrust force and the attractive force of LIM driven by the power source with the frequency component synchronous with the motor speed. In this control method, it is possible to apply the conventional vector control to the thrust force control of LIM. The frequency component synchronous with the motor speed does not generate the thrust force. Therefore the frequency component synchronous with the motor speed is able to adjust the attractive force for the levitation without the influence on the thrust force control. The controller becomes simpler by the proposed control method. We design the controller for the proposed maglev system. The simulation results show the traction and levitation control of LIM are achieved by the proposed control method.