Delta AC Motor Drive C2000 Series Applied to Electromagnetic Stirrer for China Steel Corporation

Delta Industrial Automation has cooperated with Taiwan's largest integrated steel mill, China Steel Corporation, and applied the AC Motor Drive C2000 Series to an electromagnetic stirring system used for the steelmaking process. The result has significantly improved steelmaking quality to the great appreciation of the customer.

China Steel Corporation (CSC), located in Kaohsiung, Taiwan, is the largest steel company in Taiwan, producing around 10 million tonnes of crude steel products annually. The CSC produces a range of products that includes plates, bars, wire rods, hot and cold rolled coils, electro-galvanized coils, electrical steel coils, hot-dip galvanized coils, and Ti/Ni-base alloy. The domestic market takes roughly 65% of the CSC's production and the exports take the remaining 35%. In Taiwan, the CSC takes more than 50% of the domestic market.

In the steelmaking process, raw materials such as iron ore, limestone, and coal are charged in batches into a blast furnace where the iron compounds in the ore give up excess oxygen and become liquid iron. The liquid iron is then leaded to a spure for continuous casting into billet. In the initial stage, the billet is not fully solid and still liquid inside. The electromagnetic stirrer provides a non-contact stirring method by generating a magnetic force field, reacting with electric current and creating a recirculating flow inside the iron billet to eliminate inclusions, blowholes and center porosity. It plays a key role in improving the overall steel quality during solidification.

To effectively control the current and frequency of the electromagnetic stirrer as well as to enhance facility efficiency, China Steel Corporation adopted Delta's AC Motor Drive C2000 Series (460V/315KW) for its electromagnetic stirring system. The C2000 Series features high environmental durability and modular design for easy extension and maintenance. To meet the special requirement of the electromagnetic stirring system, Delta provided customized firmware for China Steel Corporation that includes an electromagnetic stirring (EMS) mode with independent current and frequency control. Delta also customized logistic calculations to improve the 3-current balance performance. As a result, the unbalance ratio was lowered from 40% to 4% and significantly enhanced the system stability. By improving the electromagnetic stirrer, China Steel Corporation is able to effectively eliminate impurities inside the steel billet, raise the overall steelmaking quality and meet customer requirements. Delta also provided the Multi-functional Power Meter DPM-C530A Series for input and output current and voltage measurement to ensure system stability and safety.

Delta provides integrated, flexible and professional technical support to meet customer requirements. In this case, Delta replaced the original Japanese brand, and brought more benefits to the steelmaking process for China Steel Corporation. China Steel Corporation is satisfied with Delta's solution and is planning more opportunities for cooperation with Delta in the future.