交-直-交变频调速在连轧型钢主传动系统中的应用

Application of AC-DC-AC Variable Frequency Speed Control in the Main Drive System of Profile Steel Tandem Mill

随着现代工业技术的迅速发展，对型钢的品种、规格和产量的要求越来越高。在我国，连轧中型钢材生产线很少，而其中轧机主传动采用交流电机的就更不多见。交流电动机本身有着直流电动机不具备的很多优点：没有电刷和换向器、结构简单、坚固耐用、经济可靠，但因为交流电动机是一个多变量、强耦合、非线性的时变系统，因而调速比较困难。随着电力电子技术的迅速发展和计算机控制技术以及现代控制理论的引入，交流调速系统才得以广泛应用。

With quick development of modern industrial technologies, there is an increasing demand for variety, specification and volume of production of profile steels. In our country, the medium-sized steels production line of tandem roiling is very few, but a- mong them it＇s unusual to adopt AC motors for main drive of rolling mill. In itself, AC motor has a lot of advantages of not having electric brush and commutator, simple structure, sturdy and durable, economical and reliable that DC motor does not have them, but it is relatively difficult to regulate speed of AC motor due to AC motor is a time-varying system including multivariate, strong coupling and nonlinearity. Along with mushroom growth of power electronic technology and introduction of computer control technology and modern control theory, so AC speed control system just can be extensively applied.