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On the application of Sanken Rida frequency converters in the renovation of high-speed steel wire stranding machines: The company owns four high-speed steel wire stranding machines imported from the United States in the 1980s; these machines are part of the equipment used in high-pressure steel wire rubber hose production lines. It is mainly used for combining multiple steel wires in preparation for the next processing step. After years of use, its electrical performance has declined significantly. Throughout the entire processing process, the key process requirement is to achieve constant linear speed winding while maintaining a constant tension, especially during the starting and ending stages. Due to limitations in the mechanical design, the unwinding is passive. Furthermore, the guiding principle for technical upgrades is to put them into use in the shortest possible time, while minimizing costs. Under such circumstances, the operational requirements can only be met by adjusting the parameters of the inverter without altering any components. The equipment specifications are as follows: Rewinding motor: 4KW/4P; Wire diameter: φ0.28-0.30mm; Wire speed: 200-300m/min; Inverter: 5.5KW. Production process requirements: 1. The equipment must maintain a constant wire speed during operation. 2. There are no significant shocks during startup and shutdown. 3. Break wire stop protection function. 4. Slow vehicle starting function. 5. Length display function. 6. Full-line stop function. Throughout the entire production process, the key process requirement was to achieve winding with a constant tension. Since no frequency converters specifically designed for winding were available at the time of the technical upgrades, and there was no mechanism for tension monitoring and feedback, basic data on the linear speed was obtained through actual monitoring on the production site. A sub-constant-speed winding system is formed using the deceleration time and frequency settings. The specific setting parameters are as follows: Cd001: 2, Cd007: 40, Cd010: 0.5, Cd019: 15, Cd023: 1740, Cd024: 10s, Cd027: 0.1s, Cd028: 5, Cd029: 34, Cd631: 10. After several years of use, these parameters have basically met the production requirements, solving a challenge related to the technical upgrades of imported equipment. With the continuous development and maturity of variable frequency technology, as well as the increasing market demands for product quality in various aspects, the application methods of variable frequency drives from a few years ago can no longer meet the requirements of new manufacturing processes. Sanken Rida has introduced a series of frequency converters dedicated for winding in the WD line, providing a shortcut to a technical improvement solution that enables constant-tension winding without requiring major modifications to the mechanical mechanisms. Ideas for the second renovation: 1. Change from passive unrolling to active unrolling by adding an unrolling motor on the unrolling side; the load is driven by a synchronous belt, with frequency conversion control in use. 2. Replace the winding mechanism with a frequency conversion unit specifically designed for the WD series. 3. Install a tension detection system that uses signals from potential tension changes to feedback to the winding motor, enabling PID control to achieve synchronization between unwinding and winding processes. Additional electrical components added: 1. One WD05-4.OK frequency converter; 2. A 10K, 2W potentiometer for tension detection; 3. A tension frame; 4. The mechanical transmission mechanism. When setting parameters, it is important to define areas where the tension frame does not operate. While meeting the requirements of the production process, efforts should be made to minimize fluctuations in the winding curve. The unwinding process should be synchronized, and no additional regulators are needed. The target speed can be adjusted during operation based on the intensity of the tension signal, and this is integrated into the winding curve to ensure stable control of the progression. Based on actual usage, the entire system features a high degree of automation, simple operation, and stable performance, meeting the requirements of the production process.