Scientific and technical directions of improvement of electric motors for non-ferrous metallurgy

Induction motors of classical and special design modifications are used in electric drives of non-ferrous metallurgy shop equipment. Technical requirements for classic induction motors (IM) include high energy efficiency and a high degree of reliability. The most important are the requirements of high starting torque, low starting current and low dependence of startability upon the mains supply voltage fluctuations. Classic electric motors, both general-purpose and specialized, satisfy the needs of metallurgical industries in terms of starting torque, but they have overestimated values of the locked rotor current ratio by 1.5-2 times. Radical decrease of the locked rotor current ratio presents one of the topical areas of improving the IMs for non-ferrous metallurgy. The design description is given, and technical indicators of the upgraded electric motor with low starting current are pointed out. Linear induction motors (LIM) are considered as a typical example of electric motors of a special design modification. In the aspect of low material capacity, kinematic simplicity and reliability, LIMs compete with classical IM. The widespread introduction of LIMs into electric drives of workshop equipment will significantly reduce material capacity and increase the reliability of non-ferrous metallurgy. The LIM specificity is analyzed. Description of the design and technical parameters of the LIM with a short carriage are given. Regular assessments of the current technical condition of electric motors and the risk of their operability loss are the measure of significant increase in reliability of the electrical equipment of non-ferrous metallurgy. The assessments of performance risks that could be obtained without significant interruptions in exploitation of the equipment are in demand. The article presents a method for topological IM diagnostics. The electric motor diagnostic testing methodology is described, and quantitative measures of the risk of operability loss are introduced.