Abstract : A frequency converter is used in the material pick of the bucket wheel stacker-reclaimer for frequency adjustment. The whole system operates smoothly and without vibration. The safety and reliability of the whole machine is improved, and the life span of the reduction gear has been prolonged. Malfunctions and maintenance are reduced, and the system control level is greatly improved. Keywords : bucket wheel stacker-reclaimer, dual-speed motor , frequency converter 1 Introduction The bucket wheel stacker-reclaimer is a large bulk material loading and unloading equipment. Its trolley traveling mechanism was previously driven by a dual-speed motor with a working speed of 7 m/min and a shunting speed of 30 m/min. The dual-speed motor is 4/16 pole and the wiring method is Y/YY. Dual-speed motors change speed by altering the stator winding connection to change the number of pole pairs. Changing the number of pole pairs is controlled by different contactors, resulting in complex control circuitry. Because bucket wheel stacker-reclaimers are large pieces of equipment, their traveling mechanism drive trolleys are configured with 4, 6, or even 10 drives depending on the machine model and the wheel load. They have significant inertia during operation, causing considerable vibration when the trolley starts, stops, or changes speed, affecting the structural safety of the machine and the lifespan of key components in the traveling reducer. This results in a high failure rate, requiring frequent inspection and maintenance.