ANALYSIS OF VALUE PARAMETERS OF ASYNCHRONOUS MOTORS, CERTAIN ANLYTICAL AND ITERATIVE METHODS

Abstract

When designing modern asynchronous electric drives, it is necessary to know not only the basic parameters of the electric motor (nominal speed, current, moment, etc.), but also the stator and rotor circuit winding parameters, which in most cases the manufacturer does not provide. The knowledge of these parameters (phase resistances of the stator and the rotor) is a necessity when creating a full-fledged model of an asynchronous motor with a squirrel-cage rotor. To determine these parameters, it is often necessary to use various analytical and iterative methods of calculation based on the equivalent circuit of an asynchronous motor with a squirrel-cage rotor. Since the knowledge of these parameters is an integral part in the construction and development of electric drive control systems, the purpose of this work is to analyze and compare the parameters of the electric motor determined by the above methods. The parameters of the stator and rotor windings were determined for ten selected asynchronous motors with a short-circuited rotor of the AIR series. Based on the data obtained, the dependence of the phase resistances of the stator and rotor windings as a function of power was constructed. The influence of the calculated motor parameters on the static and mechanical characteristics of an asynchronous motor with a squirrel cage rotor is determined; the results of these studies are presented in the form of graphs of torque on the motor shaft (start, rated load mode and maximum load) and angular speed (nominal and critical). Based on the data obtained, the relative error for all identified parameters of the asynchronous motor was determined and a comparative analysis of methods for determining the parameters of the equivalent circuit of the engine was carried out. On the basis of the analysis obtained, the efficiency was determined, the considered methods for determining the parameters of the stator and rotor circuits for squirrel-cage induction motors in the power range of 180-7500 W.