Control of Nonlinear Dynamics of Electromechanical Systems

Abstract

This article proposes to analyze the processes in the most widely used at present frequency-controlled AC drives, as in automatic control systems with dynamic non-linearities, and structural correction methods, improving their dynamics. For the first time, dynamic formulas of transfer functions of a torque driver in an asynchronous motor with frequency control, taking into account the slip and frequency of the stator voltage, are proposed. Methods for constructing families of frequency characteristics of such electromechanical systems with “frozen” but different values of the frequency of the stator voltage and slip is described. In the Simulink application of the MATLAB software environment, families of frequency characteristics were constructed corresponding to nonlinear transfer functions. The nonlinear transfer functions obtained in this work made it possible to substantiate the structural solutions of linearizing frequency-controlled electric drives and, significantly, increasing their efficiency. Such a solution turned out to be a positive feedback on the current value of the stator current with a dynamic link. This dynamic link ensures the effective action of a positive connection without disturbing the stability of electromechanical systems. The experiments fully confirmed the correctness of the mathematical expressions obtained for nonlinear links of systems and their correction. This paper is an example of how the initial complicated (but more accurate!) Interpretation of nonlinearity allowed us to find a new best solution to the problem of controlling a complex dynamic object.