Magnetic Field and Current Displacement in Groove of Secondary Element of Adjustable Linear Induction Motor

The issues of regulation of rotational speed of induction motors continue to be relevant. It is most difficult to regulate the rotational speed of induction motors with short-circuited rotor windings, the resistance of the windings of which can be changed only by displacing the current in the rotor groove (anchor) during transient operating conditions. Linear induction motors (with “deployed” stators) have the opportunity to change the resistance of the anchor (secondary element) and control the speed, starting and traction efforts in a wide range. Adjustable linear induction motors can be used as traction machines for magnetic-levitation transport and in various electric drives with rectilinear or reciprocating motion of working bodies. The resistance of the short-circuited winding of the secondary element of a linear induction motor is changed by means of a movable element capable of closing a different number of conductors in each groove. The field problem of calculating the magnetic field in the groove of the secondary element of an adjustable linear induction motor when the closing element is moved from top to bottom and from left to right is set and solved. The regularities of increasing the active and reducing the inductive resistances of the short-circuited winding of the secondary element are established at different locations of the closing element due to the phenomenon of current displacement in the groove.