带钢热连轧轧制力模式负荷分配的改进算法

Improved algorithm for load distribution in the rolling force mode for hot strip mills

为克服压下量模式负荷分配的不足,宝钢1 580 mm过程机改造项目计划开发新的轧制力模式负荷分配方法。针对传统Newton-Raphson法对初始值依赖较大和算法容易发散等不足,提出了一种轧制力模式负荷分配的改进算法。该方法以精轧各机架的压下量为优化变量,根据轧制力成比例原则建立非线性方程组,通过推导将系数矩阵变为对角阵,避免了矩阵求逆运算;为了满足各次迭代所有机架压下量修正值之和为零的约束,添加一个修正项对各机架压下量修正值进行总体协调。提出了轧制力和压下量的超限处理方案。模拟计算验证了新算法的有效性,计算速度快,收敛性好,满足在线计算要求。

To overcome the defect of the draft ratio distribution method, Baosteel plans to develop a new distribution method in the rolling force mode in its 1 580 mm process control system reconstruction project. Because the conventional Newton-Raphson algorithm has the defects such as too much dependence on the initial value and algorithm divergence, an improved algorithm for load distribution in the rolling force mode has been presented. The new algorithm has taken the rolling draft of each finishing mill stand as the decision variable. Non-linear equations have been established based on the proportional principle of the rolling force distribution. The coefficient matrix has been reduced to a diagonal matrix by mathematical derivation, so that matrix inversion can be avoided. In order to meet the constraint that the sum of rolling drafts of all stands should be equal to zero, a correction item has been added to the draft iterative correction for an overall coordination and a process procedure for rolling force or draft overload has been presented. The simulation experiments have proved the validity of the new algorithm, which can be applied to on-line pass schedule calculation. It has advantages such as fast computing and excellent convergence performance.