Quantification of energy consumption of bridge crane in service under mechanical-electrical coupling field

To improve the evaluation accuracy of bridge cranes within a mechanical-electrical coupling field, this study proposes a transient energy consumption modeling framework that integrates mechanism dynamics with induction-motor electrical behaviors. Dynamic models of the hoisting, trolley-traveling, and gantry-traveling mechanisms are established to describe the coupled motion features of the transmission system, thereby establishing the relationship between mechanical transmission and electrical control. Considering the time-varying characteristics of the electrical system, an electromechanical model is developed to quantify instantaneous power conversion and cumulative energy expenditure. The proposed method is validated through simulations and experiments on a 1.5 t-6 m double-girder bridge crane. To capture the boundary of the model's physical validity, the experiments are strictly bounded within 20%-30% of the rated capacity (300 kg and 450 kg payloads), representing the intended operational boundary of this research. Under these representative conditions, the simulated total energy consumptions over one hoisting cycle are 16161.38 J and 18449.20 J, whereas the corresponding experimental measurements are 16439.36 J and 18787.40 J, respectively. The relative deviations (1.69% and 1.80%) lie well within the ± 2.96% expanded measurement uncertainty. The results demonstrate that the proposed framework effectively captures the dominant electromechanical energy-transfer behavior within the defined boundary, providing a theoretical basis for the green performance assessment of hoisting machinery.