Two-Level Optimal Scheduling of Electric–Aluminum–Carbon Energy System Considering Operational Safety of Electrolytic Aluminum Plants

In recent years, the mounting pressure on the integration of renewable power has emerged as a crucial concern within renewable power systems. This situation urgently necessitates an enhancement in the operational flexibility of the demand side. As an energy-intensive load, electrolytic aluminum plants have great potential to participate in the demand response. However, existing models for electrolytic aluminum load regulation lack verification of operational safety, and there is a lack of consideration of carbon trading mechanisms. To this end, this paper proposes a two-level optimization framework for electric–aluminum–carbon energy systems. More specifically, this work presents a safety-constrained electrolytic aluminum plant model, which considers operational states swinging with key parameters and limitations verified by the thermal dynamic simulations of electrolytic aluminum electrolyzers. In addition, green certificate and tiered carbon trading mechanisms are both introduced to the electric–aluminum–carbon energy. Case studies show that the proposed framework can significantly reduce the system emission by 21.9%, improve the overall economic efficiency by 16.5%, and increase the renewable integration rate by 4.5%, with an additional 8.6% of carbon reduction that can be achieved by adopting EU carbon price policies.