To ensure air exchange in henhouses, ventilation systems equipped with axial fans with three-phase asynchronous motors with speed control for continuous smooth removal of contaminated air are used. The paper presents the results of studies of the effect of power of a three-phase asynchronous motor of an axial fan on specifications of the motor when controlling its speed by changing the value of the supply sinusoidal voltage. It is determined that in the rotation range of 950–1000 rpm in this motor, the phase current of the stator winding exceeds the rated phase current by 1.5 times, which leads to overheating and getting the motor out of order in case of prolonged operation. For reliable and stable operation of the adjustable motor, the fan load power was 2 times reduced, while the maximum phase current became less than the nominal phase current of the motor, which increased the stability and reliability of the motor. However, the linear range of the control parameters was significantly narrowed, a number of engine parameters deteriorated. As a result, it was proposed to upgrade the three-phase asynchronous motor by increasing the number of coils of the stator winding, which led to decrease in power of the motor studied. As the study showed, the upgraded three-phase asynchronous motor with a fan load has improved specifications, including expansion of the linear section of the control parameter, the average values of power factor and efficiency, decrease in the average phase current of the stator winding of the motor, the lower steepness of change in the motor rpm from voltage changes. High reliability and stability of the motor were achieved and its thermal operating mode was improved. The research results allow to recommend the upgraded three-phase asynchronous motor for axial fans drives of henhouse ventilation systems for continuous smooth removal of contaminated air.
MODEL AND ALGORITHM OF PHYSICAL - TECHNICAL EFFECTS OF THE THREE-PHASE CURRENT CONVERTER OF THE ASYNCHRONOUS MOTOR
