Abstract: A large high reliability air-cooled motor with an optimal ventilation system belongs to the technical field of reliability of electromechanical power equipment, and includes calculating a flow resistance of the ventilation system and selecting the two ventilators, determining a ventilation flow rate, calculating a heating quantity and temperature rises of the motor, determining main influence factors of the temperature rise, determining random numerical characteristics of main influence factors, generating possible minimum and maximum values of running temperatures under different environment temperatures, calculating the reliability degree of the running temperature rise of the motor, creating relations between the motor temperature rise reliability and the cross-sectional area of a ventilation slot at multiple environment temperatures when one ventilator and two ventilators running respectively, and providing a motor with high reliability of temperature rise by using optimal ventilation slot area and choosi

Abstract: A prediction method for reliability degree of running temperature rise of a large and medium-sized motor belongs to the technical field of reliability and durability of electromechanical power equipment, and includes determining main influence factors of the temperature rise of a motor winding, calculating the heating quantity and the temperature rise of the motor under influences of the determined factors, determining random numerical characteristics of the main influence factors of the temperature rise of the motor winding, calculating and determining possible minimum values and possible maximum values of running temperatures of the motor winding under different environment temperatures, calculating and determining reliability degrees when the running temperature of the motor winding is less than a given temperature under different environment temperatures, and calculating and determining the reliability degree of the running temperature rise of the motor winding.