SYNTHESIS OF ELECTRIC DRIVE CONTROL WITH INHERENT NONLINEARITIES

Abstract

The paper addresses the problem of improving control performance of an induction motor drive under conditions of harmonically distorted power supply and parametric rotor nonlinearity. The relevance of the study is обусловлена the widespread use of induction motors in modern electric drives, where real operating conditions are characterized by the presence of higher-order voltage harmonics and variations in electromagnetic parameters of the machine. The research belongs to the field of electrical engineering and is aimed at improving vector control methods for electric drives considering nonlinear effects. A mathematical model of the induction machine in the dq reference frame is employed, taking into account the dependence of rotor parameters on slip caused by the skin effect. This approach enables an adequate representation of variations in rotor resistance and inductance under different operating conditions, which significantly affects drive dynamics and control accuracy. It is shown that the classical Field-Oriented Control (FOC) algorithm is based on the assumption of constant rotor parameters, which leads to flux estimation errors and violation of field orientation. It is established that this results in increased electromagnetic torque ripple, degradation of dynamic performance, and higher speed overshoot, especially under variable load conditions and in the presence of harmonic distortions. A compensation method is proposed, which involves adaptive adjustment of rotor parameters in the control loop depending on slip. Numerical simulations are performed in MATLAB/Simulink for three cases: linear model, nonlinear model without compensation, and model with compensation. The results demonstrate that the proposed approach reduces torque ripple from 20% to 8–10%, decreases field orientation error, and significantly improves the stability of the electric drive. The practical significance of the results lies in their applicability to the development of advanced electric drive control systems operating under nonlinear conditions and distorted power supply, as well as in improving the efficiency of modern industrial automation systems.