Variable Structure Speed Regulation of Induction Motor in Steel Manufacture

The integrated industry control system include frequency converter, basic automation control system, various machines, diverse sensors to realize different function and network communication system. Nowadays, the novel control and drive system is successfully applied in Baosteel heavy plate mill (HPM), one of the largest slab plants. This paper presents the design of a robust sliding mode controller for a vector control induction motor drive that employs an outer-loop speed controller using sliding mode strategy in an example-the double side shear that includes four machines of Baosteel HPM electrical drive device. In this scheme, the motor speed is controlled by a sliding mode controller. The methods of decoupling and torque linearization for the induction motor are derived from the field-orientation. Sliding mode control operation can typically reduce the dependence on accurate acquisition of motor parameters and improve the system robustness. With this controller, the dynamic and static performance of the system are studied. The controlled motor can response well to the change of speed and load. Even when drive inertia is not accurate acquired, this system also displays excellent quality. The new scheme is compared with the conventional approach using PI control. The availability of the proposed scheme is demonstrated by simulation and experiment results