Adjustable Squirrel-Cage Linear Induction Motor for Magnetic Levitation Transport

Abstract

The article deals with linear induction motor (LIM) with a squirrel-cage winding of the secondary element (SE), which functions as the armature of the machine. Linear location of squirrel-cage winding of the secondary element of LIM allowed suggesting a number of options for the regulation of the winding resistance of SE. Objective. Development and research of LIM with adjustable winding resistance of the secondary element for magnetic levitation transport, and the study of the properties of adjustable LIM. At the modern level of development of the electrical engineering, asynchronous electric drive and magnetic levitation transport, the primary method of changing the frequency rotation of motor and speed of linear motion of high-speed transport vehicles is frequency control. Frequency control allows changing the frequency of rotation of the machine and linear speed of LIM smoothly and in broad diapason. The high cost of static electronic converters of high power limits the large-scale application of frequency control. The increase of the current frequency also leads to lower torque and traction. Results. According to the authors, the application of the adjustable linear induction motors with variable resistances of short-circuited windings of the secondary elements will allow to expand the range of control of LIM, intended for high-speed magnetic levitation transport with the realisation of large traction, including the start (starting the vehicle) by means of current displacement in the groove of the secondary element of the LIM. Conclusion. The linear induction motors of this type, as well as the calculation of the magnetic field in the groove of the secondary element, and evaluation of the influence of the current displacement on the starting and controlling features of the machine are considered.