On the Issue of Optimization of Electric Car Movement with Asynchronous Electric Drive

Abstract

It is shown that the results obtained in the research of a number of scientists devoted to solving the problem of frequency control of the modes of operation of a Squirrel-cage induction motor, optimal for the criterion of minimum electrical losses, require significant correction, since they are obtained using a mathematical model of the magnetization curve approximated by two straight line segments, the top of which runs parallel to the axis of current that does not meet the physical conditions of the real functioning of induction machines and requires a stabilization of the magnetic flux in the gap at a level that is specified horizontal magnetization curve regardless of changes in frequency current in the stator winding. It is proposed to solve the problem of the optimal criterion for minimizing the losses of electric energy of frequency control of the modes of operation of a Squirrel-cage induction motor, which is a traction in the electric car, using a mathematical model of the magnetization curve in the form of an inverse hyperbolic sinus, which, with high accuracy, binds the electric current in the stator winding of the induction motor with a magnetic flux created by the field of this current, and therefore corresponds to the physical conditions of the real functioning of induction machines. Presented the results of the solution of the problem of optimal frequency control by the modes of a Squirrel-cage induction motor in the conditions of its work as a traction in the electric car motor drive system obtained using the Lagrange variational method option and the mathematical model of the magnetization curve in the form of an inverse hyperbolic sinus and which lead to the field of extremals in coordinates relative time, relative velocity of electric vehicle and relative current in winding of a stator of its driving electric motor.