The comparison of two different series of asyncronous motors under conditions of voltage assymetry

The paper considers the unbalance effect of phase-to-phase voltages in the operation modes of induction motors with the help of computer simulations, using the Matlab and Simulink packages. The relevance of the work is caused by the necessity for comparative analysis of voltage unbalance influence on induction motors of different types and capacities. Six engines of three different capacities (7,5 kW, 75 kW, 200 kW) and two different series (4A, AI) were modeled for the study. The size of asymmetry system of supply voltages was changed from 0% to 5%. The load on the motor shaft was changed from 0% to 120% of the rated load of the motor. The authors compared the dependences of the phase currents from the coefficient of voltage unbalance on the reverse sequence of k2U of asynchronous engines with a short-circuited rotor of 4A and AI series. The results are obtained in the form of tables and graphs of dependences of the investigated variables from k2U. The article presents appropriate conclusions. The authors analyze the results of dependencies ’ comparison and give recommendations for operation of asynchronous motors of 4A and AI series in terms of the asymmetry of supply voltages.