Mathematical Model for Calculating the Temperature of the Windings of an Asynchronous Motor Based on the Temperature of its Housing

One of the main parameters that ensures the standard service life of an electric motor is accordance of the insulation class of the electric motor with its current temperature. Exceeding the temperature above the standard value causes increased resource consumption and premature failure of the electric motor. Therefore, in order to reduce the costs of maintenance, repair and replacement of equipment, it is necessary to control the thermal parameters of the stator windings to prevent emergency or pre-emergency situations. Meanwhile, direct measurement of the temperature of the stator windings is not always possible. The purpose of this work is to develop a mathematical model for controlling the temperature of the stator windings of an asynchronous electric motor with a squirrel-cage rotor at a known temperature of the motor housing. The work is based on a method for determining the amount of heat transferred through the stator of an electric motor, which is represented as a flat wall. A mathematical model is presented that makes it possible to determine the temperature of its heating with a sufficient degree of accuracy based on the known geometric parameters of the motor stator and the temperature of its housing. The theoretical calculations were confirmed by experimental data obtained when the motor was opera-ting in various modes. As a result of the conducted research, the data confirming the operability of the proposed method for determining the temperature of the windings of an asynchronous motor (including the use of non-contact way) were obtained. Further work can be aimed at improving the mathematical model and the ability to monitor other points of the electric motor winding. It is also necessary to take into account the distribution of heat flows not only radially, but also along the axis of the electric machine.

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