Abstract : This paper introduces the load characteristics of domestic A-series and FA-series roving frames. The domestic A-series roving frames lack a variable frequency speed control device, and their load characteristics fall between constant torque and wind resistance load. After applying a frequency converter, soft starting is achieved, reducing the failure rate, improving roving quality, and significantly reducing fines. Keywords : roving frame; frequency converter; load; characteristics; fines; starting 1 Load Characteristics of Roving Frames The mechanical structure of a roving frame differs from that of an opening and cleaning machine, carding machine, drawing frame, and spinning frame. It is a textile machine whose main load is the roving spindle that drives the spindle blades. Actual testing shows that the load on the roving spindle accounts for approximately 60% of its motor output power. This load mainly comes from the wind resistance torque of the spindle blades. Although the cross-section of the spindle blades is designed as a streamlined shape with very low wind resistance, it still exhibits the characteristics of a wind resistance load. Table 1 shows the power consumption distribution of the A454 roving frame when the spindle speed is 915 r/min and the idle speed. Table 2 shows the power consumption of the A454 roving frame during the speed-up process. As shown in Table 2, the load of the roving frame is approximately 1.5 times the power of the spindle speed. It is well known that under constant torque load, the two have a linear relationship (1st power); for equipment with pure wind resistance load, the relationship is cubic. Therefore, the load characteristics of the roving frame lie between those of constant torque and wind resistance loads. If the motor is selected based on the maximum speed of the roving frame spindle, it will inevitably exhibit a large power margin at startup, resulting in a large starting torque. This large dynamic torque will shorten the startup time, resulting in a larger starting impact force. [b][align=center]For more details, please click: Application of Frequency Converters and Improvement of Load Characteristics of Roving Frames[/align][/b]