1 Introduction Lithography is the backbone equipment of newspapers, books, magazines, and decorating and printing industries. It has a market share of over 35% in the printing industry. With the increase in the demand for high-speed printing and high-quality printing, the total sales volume of printing machinery and equipment in 2007 was approximately 10 billion yuan, of which the export of printing machinery was 262 million US dollars and the import value of printing machinery was 1.716 billion US dollars. The renminbi is about 16 billion yuan, and the total sales of printing machinery in the Chinese market is 225 to 23 billion yuan. With the development of printing machinery technology, the export volume of printing machinery will increase year by year, and the domestic market share will increase substantially, and the demand for frequency converters will show an increasing trend. The RBS940A project is a variable-frequency drive high-speed double-sided lithographic printing machine developed by the company. The RBS940A machine includes three parts: the feeder, the delivery machine and the host. The main motor, upper and lower roller motors, and brake roller motors all require stepless speed regulation. In this model, Emerson CT series inverters were used to control four motors. 2 Inverter selection Because the spindle motor of the printing press reaches 11kW, in order to meet the personal safety during frequent low-frequency jogging during printing production and debugging, the speed control system is required to have good low-speed characteristics. At the same time, in order to reduce the waste of paper in the printing process, good fast braking characteristics are required. Finally, the drive system is required to have reliable performance. After careful inspection of the technical parameters and cost-effective analysis of each inverter, the project spindle drive selected Emerson CT's EV2000-4T00110G vector engineering inverter. EV2000 frequency converter can reach 180% of rated torque at 0.5Hz, can withstand 150% of rated output current for 1 minute, and 200% of rated output current for 0.5 seconds, meeting the frequent jogging at 2Hz of the machine tool. EV2000 has an intuitive Chinese panel display, convenient parameter copy function, and more convenient for electrical personnel. Auxiliary transmission motor such as water roller is only 0.12kW, power is small, but it requires large starting torque at low frequency, and the EV800-2S0002G single-phase inverter control with higher cost performance is selected. Motors are special motors for frequency conversion and speed control, which meet the motor thermal capacity requirements for low speed constant torque transmission systems of printing equipment. 3 control circuit design The inverter itself has many warning and protection functions such as over-current, over-voltage, under-voltage, grounding, overheating, overload, and lack of equal. These functions are enough to constitute the protection of the motor, without additional protection, directly connected to the output of the inverter. Can be on the terminal. The inverter's power input protection is relatively weak. In the power grid and the cabinet entrance we have an isolation switch breaking device. In the three-phase inverter we add a non-fuse circuit breaker with overcurrent protection, single-phase inverter. Before the addition of transformer protection, in order to prevent the power supply voltage is too high in some areas directly damage the inverter. The operation of the inverter is controlled by the PLC. The control line is directly connected to the output point of the PLC. There is no contactor control in the middle. The fault relay output point is connected to the PLC input point, and the whole machine stops operating when the alarm occurs. Since there are four inverters in this unit, interference is inevitable. When wiring, try to avoid placing the control wire parallel to the motor wire. If it is impossible to avoid the control wire, use a shielded cable as much as possible. Ground the shield and the inverter, PLC, and the ground of the motor separately. In order to make the whole machine reliable, the electric cabinet takes forced cooling. The electrical principle is shown in Figure 1. Fig. 1 Principle of main and auxiliary transmissions 4 Inverter commissioning 4.1 Main Motor Inverter (1) Main inverter operating parameters: Before the main motor is connected with the load, first set the FH group motor parameters, correctly input the data on the motor nameplate, and perform motor self-tuning work. Then input F0 group basic function parameter, F3 group auxiliary function parameter and F7 group switch quantity terminal definition parameter, debug to make all actions. The main parameter settings are shown in Table 1. Table 1 Operating Parameters of Emerson CT's EV2000-4T00110G Main Converter function code name Setting value function code name Setting value F0.00 Frequency setting 3 Analogue given F3.13 Jog frequency 2Hz F0.03 Run the command 1 terminal control F3.18 Deceleration time 2 0.8s F0.10 Acceleration time 1 10s F7.00 X1 terminal 9 punctuality F0.11 Deceleration time 1 8s F7.01 X2 terminal 10 counterpoints F0.13 Lower limit frequency 2Hz F7.02 X3 terminal 2 multi-speed 2 F2.08 Downtime 0 deceleration stop F7.03 X4 terminal 4 acceleration and deceleration time (2) Inverter running end digital display speed display: The host's speed and current display is to display the corresponding value by connecting a four-digit half-dc voltage digital display on the analog output terminal of the inverter. Because the speed of this machine has reached more than 10,000 revolutions, the decimal point is removed, but there is still a small value displayed when it is not operating. Obviously this is not appropriate. View the inverter manual, multi-function output terminal has three ways. Enable collector YI output, connect it to PLC input terminal, set F7.10 to “16†inverter alarm, programmable relay output terminal TA, TC to the signal line of the table, F7.12 is set to “ 0" frequency converter is running, so that there is still signal input when the alarm is ensured, and only after a short head line is used to achieve the operation, the value can be displayed. 4.2EV800 frequency converter The low-frequency, high-torque, single-phase, low-power inverter EV800 with the auxiliary drive such as water rollers and brake rollers is simple and practical, but its operation mode And the function is very different from the EV2000. For example, to use fast 50Hz water and potentiometer to adjust the two speed modes, according to the wiring diagram of the control, the parameter 05 must be set to AV.Pr voltage analog given frequency and preset frequency selection, and the parameter 11 start/stop logic selection. Set to 2, parameter 20 preset frequency is set to 50Hz to complete the control. Because the motors of the water roller and the brake roller are directly connected to the speed reducer, they are tentatively controlled by the V/F method. After inputting the inverter parameter, the inverter will not operate at low frequency. Check the motor connection is still star-connected 380V. Because the selected inverter is single-phase input and the output is three-phase 220V, the motor should be changed to delta connection. After the correct wiring, the situation has improved, but the motor still cannot operate normally at 5Hz, and when the frequency is increased, the speed is somewhat high. Increase the low-frequency torque boost value of parameter 42. This parameter has a great influence on the motor performance. Improper setting may cause adverse effects such as over-current, overheating, and loud noise. Therefore, the operation can be adjusted to 7%, and the normal operation at low speed can be performed. . Observing all the normal eight hours, the end of debugging. 5 Concluding remarks The superior performance of Emerson's CT frequency converter can fully meet the needs of the entire design, considerately prevent mistakes in the design of the site, to prevent the loss caused by the wrong line to damage the interface, strong ability to adapt to the bad grid, but also to make us relieve Some worries. Emerson CT frequency converters have been used in batches for more than two years on this model. They have been operating well and have never failed. This has achieved our expected goal of design selection. Aluminium Pcb Sheet,Cheap Aluminium Pcb Sheet,Custom Aluminium Pcb Sheet,Good Aluminium Pcb Sheet Jiangyin Xinren Aluminium Technology Co.,Ltd , https://www.xinrenaluminium.com