Variable frequency drive for winding solution to replace torque motor

Technical Requirements:
The features torque motor: softer mechanical feature. When the setting torque is greater than the load torque, it will accelerate automatically, vice versa, when the setting torque is less than the load torque, it will decelerate or reverse, and when the setting toque is equal to the load torque, the rotational speed of motor remains unchanged.

The torque output of torque motor, set by the controller, is applicable to constant tension wind-out and winding control, such as textile, wire, cable, metal processing, papermaking, rubber, plastic and printing machine etc.
The general variable frequency drive can only be used for AC motor open loop speed regulation, while the motor torque is out of control, so it doesn't possess the function of torque motor.

The current vector control variable frequency drive: Through complicated and accurate vector control algorithm, torque current closed loop control can be achieved for directly setting the output torque of regular induction motor control, replacing the above functions of torque motor and even obtaining higher performance.

Torque Motor and AC Induction Motor


Torque Wind-up of Film Printing Machine



Variable frequency drive system configuration:
1. Regular 3-phase induction motor: Select the number of poles and power of 3-phase induction motor based on the needs for the maximum revolution and torque in applications.
2. Open loop variable speed drive with current vector control, built-in braking unit, braking resistor selected according to motor power.
3. Regular induction motor acts constant torque control. The tension of motor can be directly set and controlled to replace torque motor without speed feedback of encoder.

Variable frequency drive system features:
1. No need for external tension detection mechanism and speed feedback encoder, simple system structure, easy for installation and commissioning.
2. The torque motor system is easily to be damaged by over-heat or improper operation. Present solutions can effectively help to protect the motor and easy for maintenance. The system is safe and stable with a long life-span.
3. The control accuracy of torque is higher than that of torque motor.
4. The taper torque can be set as auto-control mode.
5. With static friction torque compensation and large inertia acceleration torque compensation, the higher winding control performance, easy for operation.