Analysis of Current Control Options in High-Power Electric Drives of Rolling Mills

Abstract

The article is devoted to the analysis of the quality of different adjustments (like current, torque, speed) in high-power DC thyristor electric drives (with a capacity of more than 2000 kW), made using equivalent 12-pulse thyristor converters with parallel connection of valve sections through current-limiting inductor and three-winding power transformer. Modifications considered were ones with individual current controls for each valve section and with a total current control for these sections. The results of our analysis and Simulink environment modelling showed that the version with individual current control has a significantly lower (by 2-3 times) speed compared to the variant with a common current control. A decrease in the current control circuits speed leads to a decrease in the Automatic Speed Control System (henceforth ASC system) maximum speed in the electric drives in question. Recommendations on the use of different models of electric drive current (torque) control circuits for various types of rolling mills are also given in the article. © 2023 IEEE.