Multiple frequency conversion speed control systems in rubber cutting machine
Issue time:
2015-11-04 01:17
Abstract: In the rubber cut-off control system, there are conveying system, coiling system, spraying system, and cooling and down pressure system. The frequency conversion governor can realize speed matching. In the traditional control system, it is very convenient to use PLC to control the starting and stopping of the frequency converter. However, it is more troublesome to control the speed of multiple inverters and to correlate them. This article describes the Fuji man-machine interface - POD to achieve multiple inverter start and stop and speed control.
Keywords: frequency converter, POD, speed synchronization, serial communication
I. Introduction
Longda Rubber & Plastic Machinery Engineering Co., Ltd. has long been engaged in the manufacture of rubber plastic stretch cutting machines and has accumulated rich experience. However, more than one frequency conversion speed control has been using the traditional method, that is, a way to bring one, using analog to achieve the same speed, the cost of the use of synchronization card is too high. One device with one device causes a decrease in accuracy and is difficult to debug. Fuji Trading (Asia) Co., Ltd., as an agent and system integrator of Fuji Electric, combines the features of Fuji Electric's high-quality products, selects POD-G11 control system for Longda, without PLC control, and at the same time realizes all-digital communication and As a result, the high-accuracy, easy-to-debug, speed-adjustable system with rich interfaces for man-machine conversation has been completed and received widespread attention and praise in the rubber industry.
Second, the system requirements
The system is equipped with eight inverters, which are A system, B system and C system. There are 5 frequency converters in A system, 1 frequency converter in B system, and 2 frequency converters in C system. There are three parts of the system work process, namely, the whole line, cut-off and coiling three states. Each job status is divided into manual, automatic, and take-up. Because the cutting and coiling process is mainly controlled by a single unit, this article focuses on the full-line control process of multiple units.
1, the entire line of control technology
(1) Manual state: multiple frequency inverters individually controlled to start and stop individually;
(2) Automatic state: The A system C system is started and stopped at the same time, the speed of each inverter is the same, and the speed and start-stop of the B system are separately controlled;
(3) Winding state: Part A of the system frequency selective start and stop simultaneously with the C system, the speed is consistent, B system speed and start and stop controlled separately.
2, technical requirements
It is required to display 8 sets of inverter start-stop status, output frequency, motor speed, and inverter operating current at the same time on the man-machine interface. Displays the fault status of each frequency converter and the corresponding processing measures and the accumulated running time of the inverter.
Third, system design
In response to the system's requirement of multiple frequency conversion synchronization and simultaneous start-stop control, the system integration is implemented using a new generation of Fujifilm human-machine interface. The system diagram is as follows:
Figure 1 System electrical diagram
1, hardware system
The system consists of 8 inverters and a man-machine interface. The control line eliminates the need for many PLC control lines and requires only three core shielded cables for full digital control and display monitoring.
1-1-1 Inverter Selection:
Choose Fuji Electric's low noise, high performance, multi-function constant torque G11 series inverter. The inverter can achieve dynamic torque vector control, and can output 200% torque under low speed of 0.5HZ. This system uses three FRN3.7G11S-4CX (3.7KW) units, 5.5KW units, and 2.2KW units.
1-1-2 man-machine interface selection:
Fuji Electric's new generation of ultra-thin man-machine interface (POD) UG220H-SC4 was selected. The machine is 5.7 inch STN16 color, display dot matrix 320 * 240 color rich; with 32-bit RISC CPU, communication speed up to 115200bps; can be directly connected to any brand of PLC, can also be directly with the computer, SCM and other communications, comes with a printer interface , Can be connected to Ethernet; Development software powerful, can be customized, switches can be placed; adapt to the industrial field environment, high reliability; can directly with the Fuji G11, P11, E11, C11 and 6000V high-voltage frequency communication, a POD can connect more than one frequency conversion; also can directly communicate with FUJI, RKC, OMRON, Yokogawa and other temperature control tables and MODBUS protocol devices; online programming and debugging, no need to plug, with simulation capabilities, without PLC can debug the program; Multiple connections can be made, one POD can have multiple PLCs, and one PLC can have multiple PODs.
2, software system
The system software consists of a POD picture system and an inverter drive system. As the man-machine interface has a powerful programming instruction inside the macro-like PLC programming language, some PLC software functions can be completed. At the same time, the communication with the inverter is all digital, so the accuracy is high and the speed is fast.
Fourth, the conclusion
The system realizes monitoring through all-digital communication in manufacturing, reduces wiring, and completes various process control through operation only through scrolling.
