詳細(xì)說明

　　The special extrusion production line for physical foaming mainly includes: active pay-off system, wire drawing and straightening system, traction system, wire take-up system, guide wire preheating device, inner crust extruder, inflation air system, foaming extruder , cooling system, electrical control system, online monitoring system.

　　Control requirements

　　The specific control requirements of the physical foaming production line manufacturer's use site are as follows:

　　? The customer needs one 2.2kW inverter to control the front traction motor, one 2.2kW inverter to control the rear traction motor, three 2.2kW inverters to control the material extruder, one 1.5kW inverter to control the unwinding, one torque Motor controlled winding. Among them, the inverter and control requirements mainly include:

　　1. The output voltage is stable and the starting current is small.

　　2. Fast acceleration and deceleration time, good dynamic response characteristics.

　　3. The speed should be kept stable and accurate during the acceleration and deceleration process and steady speed operation.

　　4. Keep the tension constant during the cable straightening process, neither too loose nor too tight.

　　5. Excellent communication performance, multiple frequency converters communicate, and good anti-interference performance.

　　System wiring and debugging

　　The whole system is given by the controller to the inverter to run commands. ES500 series inverters have excellent performance in closed-loop vector control.

　　Debugging mainly solves two problems:

　　One is the communication problem of a large number of inverters.

　　The second is the speed synchronization between the front traction and the rear traction.

　　? Since the system controls the operation of 5 inverters at the same time, and there is also a monitoring system to monitor the running frequency, running current and voltage of the inverter in real time, the communication data volume between the host computer PLC and the inverter is large, and it is necessary to ensure The real-time nature of communication data means that when sending frequency commands, try to make several inverters receive commands at the same time, and make corresponding changes at the same time.

　　? In order to make the communication faster and more accurate, simplify part of the communication program, reduce the program time, and try to do the anti-interference work as much as possible, ground the shielded wire, ground the inverter, add a terminal resistor, and if possible, add an electromagnetic ring.

　　? In order to ensure the speed consistency of the front traction and the rear traction, we adopt the scheme of pulse speed synchronization, and send the speed of the rear traction to the front traction inverter in the form of pulses to ensure the speed consistency of the two inverters.

　　? Closed-loop tension control, the speed reference 1 of the front traction is given by the pulse of the rear traction, the speed reference 2 is given by communication, and the adjustment of speed 2 is fed back to the inverter through the analog quantity of the tension controller for PID closed-loop adjustment control. speed.

　　? Setting and debugging of extruder inverter.

　　? In the frequency conversion debugging of the winding motor, the inverter is used to replace the earlier torque motor. Here, the synchronous control and tension control of the front and rear traction are the most difficult.

　　The inverter of this system has various protection and fault output functions such as short circuit, overload, overvoltage, phase loss, stall, etc., which can effectively ensure the safe and efficient operation of the system.