Abstract: In the process of improving the production capacity and operating speed of old silicon steel heat treatment units, due to the fact that most units far exceed the original design speed limit, the stability of the looper was greatly affected, resulting in significant tension and speed vibration of the strip steel in the looper. By analyzing the principle of indirect tension control of the looper, a looper vibration suppressor was designed based on the feedforward principle, which effectively suppressed the problem of looper vibration and was applied to similar units with significant results.

Key words: heat treatment unit, looper vibration, indirect tension control, feedforward control