Swiss Steel AG, located in Emmenbrücke near Luzern is one of the leading suppliers of high quality, refined and free cutting steels to European automobile, machine and component industries.
The energy management solution delivered by ABB to Swiss Steel reduces the price of electricity by sending predicted load schedules to the electricity supplier and monitoring actual consumption. These load schedules present consumption for the current and following day at 15-min intervals.
The energy management system receives the production plans of the steel mill and hot rolling mill from the production planning systems, and calculates the corresponding energy consumption schedules. The biggest consumer is the electric arc furnace, whose load changes sharply between zero and maximum power during a melt cycle of around 50 min. The rolling mill’s consumption depends on the type of end product and the mill train in operation.
Due to the electric arc furnace the load schedules exhibit a strong time variation. If the consumption schedule is not correctly predicted, the electricity supplier incurs additional costs, which are transferred to the user in the form of penalty charges. To avoid these penalties, any changes in production plans or disturbances in operation are continuously updated in the energy management system, and the revised load schedules are sent to the electricity supplier. Operators monitor consumption using the tie-line monitoring display that activates an alarm if a deviation leading to a penalty charge is expected.
The energy management system allocates the energy costs to the users (mill departments). The penalty fees are shared between those users that have caused them by not consuming energy according to the predicted schedule. This will motivate the users to improve the planning of their operation and results in reduced energy cost to the entire facility.