Demand Side Management Scheduling Formulation for a Steel Plant Considering Electrode Degradation

Stainless steel production consumes a large amount of electricity. Demand side management (DSM) has been identified as a key way to reduce costs in steel plant operations by responding to time-varying electricity prices. The electric arc furnace (EAF) is responsible for the majority of a steel plant's electricity consumption and has been identified as having sufficient flexibility to participate in DSM schemes as it is run in batch mode with variable operating settings. Often neglected in steel plant scheduling is the degradation of the electrodes of the EAF units and the associated cost of replacing them. However, there exists a complex trade-off between the intensity at which the EAF is operated, and the lifetime of the electrode. The intensity in this case also strongly affects both electricity consumption and the length of a batch. This work proposes a novel scheduling formulation that explicitly considers DSM and its relation to electrode degradation. Results show on the one hand, that the novel formulation is able to more realistically model the EAF operations by explicitly considering electrode consumption. On the other hand, the model is also able to effectively balance the trade-offs between DSM-related costs and electrode replacement costs by extending the lifetime of the electrodes while still having the flexibility to be able to participate in DSM schemes. (C) 2019, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.