Papers by Keyword: Linear Induction Motor

Abstract: This article presents the design and construction of a mini magnetic levitation train. The design of the train is based on the theory of 3-phase Linear Induction Motor (LIM). The train consists of two main sections. The first part is the linear induction motor, which is the part that drives the train to move. The second part is the magnetic field winding, which is the part that raises the body of the train to float over the rails. Such train can move forward/backward in the same principle as forward/reverse rotation control of 3-phase induction motors. For that reason, this research controls the forward/backward movement of the train with a magnetic contactor set by using the same circuit as the control of the rotation of the 3-phase induction motor. The designed train can lift 1 mm above the rails and move within a distance of 1.48 m along the length of the rails. The test results showed drive voltage, drive force, average time and drive speed of the train. From the details and results of this article can be used as a guide to create a larger magnetic levitation train, which can be used more effectively.

Abstract: The submitted list of scientific publications and literature indicate, that so far there have never been comprehensively analysed the braking modes of the Linear Induction Motor (LIM) with a short secondary part. The article deals with the theoretical simulation model of such a LIM, containing even, odd or fractional number of the active (excitation) zones. The spectral analysis method is used to calculate the spectral characteristics of the motor braking. After having applied, Fourier and Laplace integral transformations for the non – periodic volumetric density functions of the braking current, there have been derived the analytical expressions of the continuous amplitude spectra. These obtained expressions successfully meet/harmonize the analysis of spectral characteristics of the primary and secondary magnetic field.

Abstract: Electric catapults can be used for automatic information storage in radioactive environment. Dynamics of a transport system with the potential of route flexibility was investigated. This system is made up of stand-alone modules, therefore further expansion is possible. Modules consist of mechanical part (rails for the cart), electrical part (inductor of a linear induction motor (LIM) and electromagnetic brake) and electronic part (thyristor commutator). Cargo cart is mounted on the LIM’s secondary unit that can be catapulted from any station (module) to another. First LIM’s inductor starts the secondary, ejects it out of primary’s range. Inertia of the cart allows it to reach the next station which in turn can either accelerate it or stop it. Position detectors (Hall effect sensors) are used for estimating cart movement. Electromagnetic brakes are used as dynamic braking is not effective in this case. A computer model was designed and various operating modes are simulated (upon non-zero initial conditions).

Abstract: A new kind of magnetic elevator is presented in this paper, and the traction force of elevator is provided by the double long-primary short-secondary linear induction motor. The elevator has the advantages of simple structure, less heat, good adaptability. The circuit model of traction motor is established. Magnetic elevator running speed curve is analyzed, and the VVVF control system of linear induction motor for magnetic elevator is designed, and the double long-stator windings are piecewise controlled. Through simulation, the feasibility of the magnetic elevator is verified. The paper laid the solid foundation for the further application.