Abstract: A new online motor power model was put forward to improve the motor power calculation accuracy. In the model， the motor power was divided into two parts: rolling power and mechanical power loss. The rolling power was calculated by the simple finite element numerical integration method， and the mechanical power loss of the motor was obtained through field test and the regression method. Based on the proposed test scheme and model structure， the coefficients of the power loss model were obtained by using the actual test data of a 1450mm 5- stand tandem cold mill. The proposed power model was applied to the 5-stand tandem cold mill. The application results showed that this model is accurate and the relative error of motor power prediction is within ±5%， which can meet the requirement of online process control and has a good application prospect.

Key words: cold rolling, rolling torque, rolling power, simple finite element, power loss test, mathematical model