Study On Main Drive Control System Of 20 Rollers Reversible Cold Rolling Mill

With the development of the iron and steel industry and the increase of billet weight, as well as to improve the rolling speed and the increase of the main motor power, main drive system of steel rolling at home and abroad, which have both had seriously damage accident. One of the main causes of the damage is the problems of main drive control system. The performance of mill main drive control system directly affects the production efficiency and quality, so the world industrial developed countries have invested a lot of manpower and resources to study the control system of mill main drive system. In this paper, taking the engineering design of Angang High Performance Silicon Steel 20 rollers reversible cold rolling mill as the research platform, the main drive system are studied from the angle of electrical design.Main drive control system design is a complex problem, there are many transmission schemes. The optimization of the scheme is the precondition for the further design, directly affects the design results. So this paper compare the main drive control schemes firstly, then finalize the main drive control scheme of AC-DC-AC converter with common DC bus pulse and PWM full digital vector control variable frequency speed control system, and chose CONVERTEAM company ALSPA MV7000 medium voltage inverter. The main drive transformer decided to adopt dry type rectifier transformer. The main drive motors decided to adopt squirrel-cage asynchronous motors.On the basis of in-depth study on the theory of control engineering, the composition of the main drive system are studied, and it is completed in scheme design of AC-DC-AC converter with the variable frequency speed regulation system, and then it is introduced in detail in this paper that the key technology of main drive control system such as the use of BEGT high-power components that make the inverter has higher reliability; the use of AFE that make the net side current is little harmonic sine wave and the power factor is close to 1; the use of 3-level Neutral Point Clamped inverter unit that ensure superior motor voltage waveform to be output and the motor current to include lower harmonic current; the use of using high-performance controller with the configuration of the vector control software that can provide high performance PWM vector control calculation and ensure the safety of the converter.Based on the above theoretical research it is completed that the calculation of transformer capacity and the design of transformer parameter; and that selection design of the main drive inverter type; and that the parameter design. Then the hardware equipment installation and commissioning of the control system are done.After commissioning and running of 20 rollers reversible cold rolling mill in Angang High Performance Silicon Steel, the product is good and high dimensional accuracy, and the technical performance have reached the design requirement. The main drive control system is stable and reliable with high control precision, convenient operation and simple maintenance and so on, so it verifies the correctness and feasibility of the design in this paper. Practice has proved that AC-AC variable frequency control of the main drive converter device increasingly should be replaced by AC-DC-AC mode in the future of cold-rolled production line.