Constant-tension control system of carbon fiber filament take-up machine

The invention provides a constant-tension control system of a carbon fiber filament take-up machine. The constant-tension control system comprises a PLC, a servo driver, a servo motor, a magnetic powder brake, a filament take-up machine transmission part, a sensor and a filament take-up machine main roller, wherein the PLC is connected with the servo driver through a communication line, the servo driver is connected with the servo motor through a communication line, the servo motor is connected with the magnetic powder brake, the magnetic powder brake is connected with the filament take-up machine transmission part, the filament take-up machine transmission part is movably connected with the filament take-up machine main roller, and the magnetic powder brake, the sensor and the PLC are connected through signal lines. The constant-tension control system has the advantages that constant-linear-velocity rotation of the servo motor is achieved through a PLC construction algorithm, constant tension is guaranteed, the phenomena that carbon fiber filaments are broken and carbon fibers get loose on the roller because of non-constant tension control are avoided, the fiber spreading process requirement is met, the level of quality control over protofilaments is increased, and the production cost of the carbon fibers is lowered.