Dynamic Modes of Electromechanical Systems under Parametrical Disturbances

Abstract

The results of a theoretical and experimental investigation of the influence of damping and pitch plays on the dynamics of electromechanical systems in the zones of main, harmonic, and subharmonic resonances under parametrical disturbances are presented. Design models of electromechanical systems taking into account spring linkages, pitch plays, mechanical damping, and inconstancy of a gear ratio and reduction radius are proposed. The equations and structural schematics describing the movement of electromechanical systems under consideration in the initial values and adopted system of generalized parameters and relative units are presented. The electric drive is described by a linear mechanical characteristic taking into account the electromagnetic inertia of power circuits. The problems of linearization of electromechanical systems under parametric disturbances are considered, and the zone parameters are revealed under which it is possible. The analytical relationships for determining the optimum parameters of electric drive and the estimation of resonant amplitudes of oscillations of the elastic torque are obtained. Results of analysis of the influence of pitch-play formation on the oscillations in the zones of main and subharmonic resonances are presented. Features of these oscillations related to the magnitude of average load of transmissions and the direction of change in the frequency of parametric disturbances are considered. The reliability of theoretical regulations and conclusions of the article are confirmed by the results of industrial experience in the use of various circuits of a reduction-gear electric drive of rotation of an excavator under parametric disturbances caused by a gear wheel meshing with the gear ring.