A paper-making plant in Tianjin uses DC speed regulation for post-drying, calender and paper rolling machine in the paper-making production process. Presently, the INVT-CHV100 inverters are used for drive control of the multi-motor parts. The specific control requirements are as follows: (1) all the five inverters adopt closed loop vector control, to increase the variable frequency speed regulation control precision and the system start capability. (2) The first three dryers and the fourth calender should operate at the same linear speed. (3) The fourth calender should have the function of automatic conversion from torque to speed. When operating in torque control mode, the calender can perfectly balance the tension change of the paper after output from the post-drying roller, to effectively avoid damage to the paper surface due to slippage upon press polishing, and meanwhile, to provide perfect paper feeding conditions at the winding side. (4) The fifth one is used for paper winding control (paper rolling machine). It is required that the tension should be constant upon winding. This system does not have tension feedback; therefore, the tension-free feedback torque control mode is used for control at the paper winding side. The electric wiring diagram of the control system is shown as follows:
Electric Control Diagram of the Paper-making System with Five Drive Points
The first inverter in the system adopts the AI1 channel to set frequency. The second through the fourth inverters adopt the “A+B” mode to set the frequency. The main frequency “A” uses the inverter Analog output “A01” signal of the previous stage to make setting, and overlap frequency “B” uses AI2 channel to set, serving as the fine tuning of the drive speed, so as to implement synchronous operation of the system. The fifth inverter adopts the control solution of “CHV100 + PG card + tension card”. The tension control mode is: tension-free feedback speed control. The linear speed method is used to measure the winding diameter. The setting of the linear speed originates from the analog output “A01” of the fourth inverter. The relay output serves as fault indication.
n Parameter Settings
1) Inverter 1
P0.01 1 Vector control with PG
P0.01 1 Terminal command channel
P0.03 1 AI1 setting frequency
P0.11 5 Acceleration times 0
P0.12 2 Deceleration times 0
P2.01 50 Rated frequency of motor
P2.02 1460 Rated rotation speed of motor
P2.03 380 Rated voltage of motor
P2.04 23 Rated current of motor
P2.05 11 Rated power of motor
P3.10 1000 PG parameter
P3.11 1 PG direction selection
P5.02 1 Forward operation
P5.03 7 Fault reset
P5.04 6 Free stop
P6.04 3 Fault output
2) Inverter 2 through 4
P0.00 1 Vector control with PG
P0.01 1 Terminal command channel
P0.03 1 AI1 setting frequency
P0.04 0 AI2 setting frequency
P0.06 2 A+B frequency setting
P0.11 5 Acceleration times 0
P0.12 2 Deceleration times 0
P2.01 50 Rated frequency of motor
P2.02 1460 Rated rotation speed of motor
P2.03 380 Rated voltage of motor
P2.04 23 Rated current of motor
P2.05 11 Rated power of motor
P3.10 1000 PG parameter
P3.11 1 PG direction selection
P3.13 30% Keypad setting torque (Inverter 4 setting)
P5.02 1 Forward operation
P5.03 7 Fault reset
P5.04 6 Free stop
P5.05 3 Torque control disabled (inverter 4 setting)
P6.04 3 Fault output
3) Inverter 5
P0.01 1 Vector control with PG
P0.01 1 Terminal command channel
P0.11 5 Acceleration times 0
P0.12 2 Deceleration times 0
P2.01 50 Rated frequency of motor
P2.02 1440 Rated rotation speed of motor
P2.03 380 Rated voltage of motor
P2.04 8.9 Rated current of motor
P2.05 4 Rated power of motor
P3.10 1000 PG parameter
P3.11 1 PG direction selection
PF.00 1 Tension-free feedback torque control
PF.01 0 Winding mode
PF.04 120 Maximum tension
PF.06 63 Tension digital setting
PF.10 25 Tension taper coefficient
PF.11 1 Mechanical drive ratio
PF.12 1.52 Maximum winding diameter
PF.14 0.5 Winding diameter 0
PF.18 0 Linear speed method
PF.22 260 Maximum linear speed
PF.23 1 AI1 linear speed input
PF.24 0.5 Maximum linear speed
PF.33 5 System inertia compensation system
PF.34 800 Material density
PF.35 1.5 Material width
n Summary
Practice shows that, the INVT-CHV100 PG vector (closed loop vector) variable frequency speed regulation solution can perfectly meet such control requirements as speed setting, speed fine tuning, acceleration/deceleration control, speed/torque switchover, load allocation and winding during paper-making production. With the application of the CHV100 high-performance vector inverters, the system features large start torque, powerful overload capability, quick dynamic response, and high speed stabilizing precision. INVT-CHV100 inverters provide perfect solutions for paper-making machinery, which omits the PLC, reduces power consumption, improves the productivity, and saves more costs for users. Therefore, the INVT-CHV100 inverters have found wider and wider application in the low-speed and medium-speed paper-making industry.
n Reference
1. User Manual for CHV Vector Inverters Shenzhen INVT Electric Co., Ltd.
2. User Manual for CHV Vector Inverter Extension Card Shenzhen INVT Electric Co., Ltd.
3. Paper-making Processing and Technology Chemical Industry Press