Impact of Load Sharing Among Induction Motor Drives on Reliability and Life Expectancy

In modern industrial applications, multiple induction motor drives (M-IMDs) are commonly used to meet specific load requirements. Ensuring the reliability of these systems is essential, as thermal stress is a major factor contributing to the degradation of insulation materials, bearings, and other critical components. Prolonged exposure to elevated temperatures can lead to insulation breakdown, overheating of stator and rotor windings, and, consequently, a reduction in the motor’s lifetime (LT) and overall efficiency. This paper proposes a novel reliability assessment framework for M-IMD systems, specifically focusing on applications that already utilize a predetermined number of induction motor drives (IMDs). The proposed approach introduces an effective load-sharing criterion that optimally distributes the mechanical load among the existing motors, enhancing efficiency and extending operational LT. By ensuring an optimal division of the load, the model minimizes power losses and mitigates thermal stress, leading to improved system performance and reduced operational costs. Additionally, a cost analysis per operational hour is conducted for a given number of IMDs. The proposed methodology is validated through simulations of various load profiles with different numbers of mechanically coupled IMDs, as well as experimental hardware results under diverse loading and speed conditions.