The electrical automation system of the No.2 blast furnace project of Hebei Famous Iron and Steel Co., Ltd. has been officially put into operation. The two-wire analog input and output signals enter the PLC system through an isolator, and the on-site switch input and output signals are isolated by relays. Chinese annotation of variables is required in the control program, and all program blocks cannot be encrypted. Chongqing Langwei has undertaken the project and has shipped nearly 2000 complete sets of signal isolators.

The automatic control system of this blast furnace adopts a PLC system mechanism. To provide system stability, Siemens S7-1500 series module PLC is used, which is a PLC main station remote station structure; The selection of PLC shall fully consider its reliability, stability, economy, practicality, progressiveness and expandability, and shall meet the requirements of medium and high control performance and the strict requirements of blast furnace industrial environment. The PLC master station should adopt a modular structure, and all programmable logic controllers (PLCs) should be adapted to work in industrial environments and electrical interference conditions. The top PLC and coal injection PLC under the trough adopt a redundant scheme to improve the stability of the system. The redundant system is hardware redundancy, including redundant power modules, redundant CPU modules, redundant Ethernet and bus communication modules, redundant ET200 stations, redundant backboards, etc.

This control system should have considerable flexibility and scalability while meeting the requirements of the blast furnace process. The data communication network adopts a single-mode fiber optic Ethernet ring network. One centralized control room is set up in the main control building to complete the centralized control, operation, and management of the entire factory's production equipment and production process. All operation station screens can be switched to each other, and the screen switching time should not exceed 1 second.