Optimal control of Permanent Magnet Synchronous machines for cold rolling mills

Abstract

The objectives of the steel manufacturers are to improve their productivity and to optimize their process parameters to maximum efficiency and quality. In steel industry, the one or the more client motors are often arranged to follow the velocity of the master motor. The speed difference between these motors will affect the tension of the product. Hence, the synchronized control and the tension control are the important research topics in the strip manufacturing process. This paper proposes a novel multi-input-multi-output optimal control system for the synchronism control of dual motor system. The control strategy has in view the synchronization of the dual motor system in optimal manner combined with designing of an appropriate reference filter in order to obtain a zero steady state error between the references and the corresponding feedback signal values; the Permanent Magnet Synchronous Motors (PMSMs) operating with constant (rated) flux. The dual motor system was linearized in Matlab/ Simulink. This method employs a simplified model of the plant to be controlled. The simulated results indicate that the method is highly effective and the precision is better than that of the traditional state feedback methods [1]-[3]. Simulation results will show the feasibility and the practicability of the proposed optimal controller. A study of conventional control applied to permanent magnet synchronous motors has also been performed.