METHOD FOR LOADING AN ASYNCHRONOUS MOTOR AND A DEVICE FOR THE REALIZATION OF THE METHOD

The proposed method for loading an asynchronous motor implies periodically varying the frequency and voltage of the motor power supply, measuring the phase currents and voltages of the motor stator, determining the instantaneous and amplitude values of the currents and voltages, and determining the temperature of the stator winding under the motor overload. The method is distinctive by connecting, in the circuit of each phase winding of the motor, a capacitor, which capacity provides the conditions for resonance in the circuit with inductive reactance equal to the short-circuit inductive reactance of the motor, setting the frequency and voltage of the motor power supply that are required for achieving the preset rotation frequency of the motor, maintaining the current and the rotation frequency of the motor that correspond to the preset loading mode of the motor, and determining the characteristic that describes the dependence of the motor torque on the rotation frequency, harmonic components of the phase currents and voltages, and the parameters of the equivalent circuit of the motor. The proposed device for the realization of the method contains a frequency converter to which a motor can be connected, a control unit, and additionally, a capacitor bank, a phase current and voltage transducers for the motor, a switching unit, an analog-to-digital converter, a digital-to-analog converter, and a computing unit.