The floating crane supply system usually incorporates large-capacity multiple asynchronous motors. During the starting process of these motors, simultaneous activation can result in substantial current surges. Consequently, the transformer bears a heavy current burden, potentially triggering the false overcurrent protection and leading to further industrial production losses. This paper investigates a protection scheme for transformers supplying multiple high-capacity motors. Firstly, the mechanism of the overcurrent during motor starting is analyzed by an equivalent model. Subsequently, a random scenario generating algorithm is proposed to generate a large number of scenarios for analysis. Furthermore, the Hilbert-Huang transform technique is employed to examine the time-frequency domain characteristics of both fault current and normal current, leading to improvements in the conventional overcurrent protection scheme. Finally, The effectiveness of the proposed protection scheme is validated through a realistic floating crane supply project in Hunan province.