A Control Method for Load Balance between Upper and Lower Roll of Four-High Hot Rolling Mill

In the rolling process, the upper and lower working rolls of the mill usually under different load. In order to keep good product quality, load balance control is necessary. This paper proposes a control method which uses the torque difference between upper and lower roll to compensate the given current of the upper roll motor. Simulation results show that the proposed control method can give good control effect and keep load balance.