Abstract : Addressing the specific requirements of multiple spindle motor parameters and external interlocking control in grinding machine retrofitting, a scheme was designed to drive multiple spindle motors using a single dedicated high-frequency inverter. This successfully solved the problems of wide voltage and multi-parameter configuration, and achieved excellent results in practice. Keywords : High-frequency inverter, spindle motor, wide voltage 1 Introduction With the development of frequency conversion technology, its application fields and demands are becoming increasingly diversified. A Swiss-made VOUMARD 203N3X3Y internal grinding machine malfunctioned due to a broken electrical control system, preventing normal operation. Considering that the machine was an imported product, old, and could not be repaired independently, and that repair and purchase costs were high, the manufacturer decided to retrofit it. The VOUMARD 203N3X3Y internal grinding machine has five types of electric spindles for the grinding head, each with different parameters. A dedicated frequency inverter and corresponding control components were required to complete the electrical control of the system and achieve spindle speed regulation. This paper analyzes the characteristics of five types of grinding head spindle motors in the equipment, proposes and analyzes two solutions, selects one with better cost performance, and achieves good application results. [b]2 Driving Requirements and Scheme Comparison 2.1 Driving Requirements and Difficulties[/b] (1) Grinding Machine Spindle Motor Parameters The grinding machine spindle motor parameters provided by the manufacturer are as follows: No. 1 grinding head working frequency 933HZ, maximum speed 28000r/min, power 2.3kW 448V 4.5A; No. 2 grinding head working frequency 900HZ, maximum speed 18000r/min, power 3kW 432V 6.6A; No. 3 grinding head working frequency 966HZ, maximum speed 58000r/min, power 1kW 465V 1.75A; No. 4 grinding head working frequency 1250HZ, maximum speed 75000r/min, power 1.3kW 191V 9A; No. 5 grinding head working frequency 2000Hz, maximum speed 105000r/min, power 0.53kW 306V 2A. [b][align=center]For details, please click: Design of a Solution for Driving Multi-Spindle Motors with a Single Dedicated High-Frequency Inverter[/align][/b]