Совершенствование автоматизированных электроприводов агрегатов прокатного производства

Abstract

Although the majority of domestic metallurgical enterprises purchase and install processing lines from foreign suppliers, development, implementation and promotion of domestic equipment is still an urgent and challenging task. Technological achievements of the joint research teams from Magnitogorsk State Technical University, the South Ural State University and the OJSC “Magnitogorsk Iron and Steel Works” (OJSC “MMK”) are described in the article. One of the priorities in the research work is energy saving both in electric drives and in automation equipment of electric drives. The authors describe the approach and the technical solutions providing reduction of electric power losses due to the reduction of reactive power consumption by thyristor electric drives of rolling mills. Technical efficiency is achieved thanks to the reduction of the thyristor voltage converter storage without any compensating devices. Some algorithms and software providing energy and resource saving due to improvement of the speed and load modes of electric drives in the process of plate production from the difficult-to-form/hard steel grades are given. The structure of the automation system for 5000 plate mill rolling stand is presented. Local systems of the automatic end-point control providing adjusting of certain technological variables are described. Automation of level 2 ensuring the production process control according to the schedule predetermined by the operator is considered. Great attention is paid to the developed resource saving electrical systems of the wide strip hot rolling mill. The authors introduced a complex of scientific developments aimed at improvement of automatic electric drives and process variables control systems. The resource saving is provided by reduction of specific consumption of materials as a result of defective product reduction and the decrease of wastes caused by strip end crops. The authors studied the system of automatic tension control with an extra fast acting channel adjusting the hydraulic screw-down structure of the rolling stand. They intro-duced the method and the algorithm of tension control in the intestand gaps of the hot rolling mill roughing train. All the de-veloped control methods and algorithms have been implemented into the operating rolling mills of the OJSC “MMK”. The main advantages of the developed solutions are high efficiency and relative simplicity of implementation/putting into practice. The introduction of the algorithms will improve the production capabilities of the operating and new rolling machinery, contribute to production efficiency improvement, resource and energy saving and make the final product more competitive in the market.