Download PDF Abstract Now in connection with a steady trend of application of asynchronous motors practically in all industries, there is frequently a necessity for calculation of parameters of the motor, which are not present in the reference data. Knowledge of the following asynchronous motor parameters in various operating modes is required: idling mode, nominal mode, arbitrary load mode, starting mode. Their calculation is based on substitution schemes, the accuracy of which depends largely on the accuracy of the calculation of current and no-load losses. In this article, a number of well-known theoretical and practical methods for calculating current and no-load losses of idling speed are considered. The substantiation of a possibility of no-load current calculation is carried out on the basis of reactive power balance of an asynchronous motor for nominal mode according to motor passport data. The rational expression for no-load current calculation is obtained. The considered methods of no-load current calculation and the data given in the reference literature are investigated with reference to two types of boosters from the power group up to 100 kW and power 1000 kW. Within the framework of the research, idle current calculations were carried out on the basis of passport data of the considered motors and the evaluation of the obtained results was given. It is established that the expression for no-load current calculation obtained from the condition of reactive power balance in the nominal mode gives the closest values to the results of calculation using the basic method based on the data for the nominal mode and their values at partial loads on the engines. Keywords Asynchronous motor, parameters, energy diagram, nominal mode, partial load, idle current, calculation methods, calculation graphs, energy curves, tabular data, reactive power balance, comparison of results.