1：The paper machine frequency control system Introduction Paper machine
Paper machine structure consists of headbox, wire section, press section, dryer section, calender, rolling and several parts.
Transfer system is made up of multi-part system, With convenient accurate speed control function:
- ● Transmission between each part can maintain fixed transmission ratio, make each point of the line transmission speed remains the same, beneficial for equipment acceleration, deceleration, can avoid by 2. Drag the machine running smoothly continuous.
- ● Drag the machine running smoothly continuous.
- ● With smooth acceleration and deceleration function.
- ● Each point can be individually start and stop, fine-tuning, and has crawl and acceleration function.
- ● A speed chain relationship between each point, if the front speed change, the back-end automatically follow.
2：Paper machine production line synchronization control has the following five ways
- ● Speed box + slip speed motor
- ● Synchronization controller+ZC1000 inverter + squirrel-cage asynchronous motor , there are multiple input/output ,With a high-precision multi-turn potentiometer to adjust synchronous controller, Set speed chain model in the synchronous controller, and then output by synchronous controller 4-20mA / 0-10V analog signal control each inverter. advantage: Simple low-cost transformation. Disadvantages : Analog signals are susceptible to interference, the accuracy is not high easily cut paper, Life is 18 months .
3：ZC1000 inverter pulse synchronization control by a inverter act as a host, it can send out a pulse signal to multiple inverters, in proportion to run the synchronization control.
- ● Advantage: Linear velocity accuracy is higher than the synchronous controller, easy to use .
- ● Disadvantages : Still has the problem of accuracy is not high
4： PLC host + D/A module +ZC1000 inverter + squirrel-cage asynchronous motor Will switch signal to PLC, for BIN integer/floating-point arithmetic, and then A scale of 0-4000 to A numeric value through D/A conversion module for 4-20mA, or 0 to 10 v analog signal output to the inverter
- ● Advantage: Line speed precision is higher than the synchronous controller, it can keep the memory when the power cut, Use buttons instead of potentiometer to ensure the accuracy.
- ● Disadvantages : Process of the high cost of renovation, still has the problem of analog accuracy is not high
5：PLC master-slave communication with ZC1000 inverter
ZC1000 inverter Modbus communication card use the way of master-slave query - corresponding mechanism , When the query is issued as long as the master, the slave response is given, the master cannot make a data from the station. PLC as the master receiving external signals by 485 communication port , and make communication with each inverter from station, send commands and receive data., and could be controlled by touch screen in real time. as a result of the master-slave communication high synchronization accuracy, without interference, and eliminates the paper machine industry D/A module used in the traditional control mode.