Abstract : Based on the actual situation, production process, and requirements of modified bitumen waterproof membrane production lines with an annual output of over 5 million m², this paper introduces the necessity, working mechanism, and characteristics of frequency converters (VDCs) in automatic felt rolling machines. It points out that the automatic felt rolling machine has unique advantages and good operating performance after using a VDC. Keywords : Automatic felt rolling machine; Frequency converter; Speed ​​regulation 1. Problem Statement Modified bitumen waterproof membrane production lines with an annual output of over 5 million m² have a large production scale, with many pieces of equipment in the membrane forming section, long distances between sections, and high linear speeds. Many issues need to be considered in the design, manufacturing, and use of the equipment, and many factors influence its practical application. Therefore, this large-scale membrane production line is not simply a scale-up of a smaller production line; it places higher and more complex demands on all aspects of the production system. It must not only solve problems such as cooling, deviation, and tension under high-speed conditions, but also complete the rolling and packaging of various types and specifications of membranes within a certain time while ensuring the appearance quality of the membrane rolls. In commonly used semi-automatic felt rolling machines, the rotational speed n (or angular velocity w) of the winding rod remains essentially constant during operation. Since the linear velocity v=wr, the linear velocity gradually increases as the radius r of the felt roll gradually increases; however, for the same roll diameter but with different winding rod rotation speeds, the linear velocity of the felt roll will also differ. The approximate linear velocities for the felt roll in these two cases are shown in Table 1. [b][align=center]For more details, please click: Application of Frequency Converters in Felt Rolling Machines of Modified Asphalt Waterproof Membrane Production Lines[/align][/b]