The variable frequency control drive unit is applied to the winding main torque control and vector control mode. In the torque control mode, the variable frequency control drive is equivalent to the torque motor drive, is a lower level of frequency control, suitable for insensitive winding occasions. In the vector control mode, the inverter control of the motor using the speed and torque separately separate way, is a more advanced frequency control, suitable for sensitive winding occasions, can achieve constant tension winding.