Foreword:
More and more rewinders and unwinders are adopted in electronics industry, machinery industry and manufacturing. The stable tension function is necessary in the rewinder and unwinder for good product quality and effect. With the complete function and gradual mature of asynchronous motor control, the AC motor drive becomes the main product in constant tension control.

Delta VFD-BW series: Applications of unwind metal wire control

1. System introduction
The main operation of wire winding machine is to make a large bundle wire to be a small bundle wire with orderly arrangement. So it is significant for the function of stable wire arrangement and tension used in the application.

The system structure diagram is made up of three parts, unwinder, tension control and rewinder as shown in the following. It is controlled by Delta DVP-EH series PLC and set parameters from Delta HMI.

In rewinder, it uses 5.5kW motor+055B 43 AC motor drive, the frequency command of AC motor drive is from PLC and arrange wire by Delta Servo.

Because it provides rewind and unwind function in Delta VFD-BW series AC motor drive, the constant tension control, auto calculation of reel diameter and auto PID adjustment can be finished without PLC. Therefore, it can complete unwind operation independently in this system instead of DC speed adjustment.

2. The wiring diagram is shown as follows