МОДЕЛИРОВАНИЕ АСИНХРОННОГО ЭЛЕКТРОПРИВОДА ДЛЯ ИССЛЕДОВАНИЯ ПРОЦЕССА ПУСКА

Abstract

A model of an asynchronous motor is proposed, which makes it possible to investigate the process of motor acceleration, taking into account changes in the resistance of the rotor circuit, consumed current and voltage in the power supply network. A method for calculating the parameters of the equivalent circuit of an asynchronous motor according to passport data is proposed, the calculation takes into account changes in the resistance of the rotor circuit during start-up. The electric motor model is based on a static mechanical characteristic with a linear dependence of the rotor resistance on slip. The model is designed to study the electromechanical parameters of the electric drive during the start-up process, taking into account the parameters of the power supply circuit. The analysis of existing functions for modeling the mechanical characteristics of an induction motor was carried out and a formula was chosen for determining the electromagnetic torque from the parameters of a simplified L-shaped equivalent circuit without taking into account electromagnetic transients. Therefore, the proposed model based on the static mechanical characteristic is applicable for mechanisms with a long start. The parameters of the equivalent circuit of an asynchronous motor are determined according to the passport data. The dependence of the rotor circuit resistance on slip is described by a linear function of the first order. The results of calculating the mechanical characteristic according to the compiled model do not differ from the parameters at four known characteristic points corresponding to the passport data of the induction motor. Because when calculating the no-load current and the active resistances of the stator and rotor windings, some assumptions were made, it should be noted that the proposed method is preferable for calculating high-power motors.