A Bi-level Programming Guiding Electrolytic Aluminum Load for Demand Response

The electrolytic aluminum accounts for about 7% of China's total electricity use and has great potential for demand-side response (DR) with smart grid technologies. This paper focuses on the optimal scheduling of the electrolytic aluminum with DR function. The bi-level optimization model is proposed to guide electrolytic aluminum load for providing DR. In the proposed optimization model, the upper-level problem is to minimize the system operational cost, while the lower-level problem is to maximize the profit of the aluminum plant. The Karush-Kuhn-Tucker optimality conditions for the lower-level problem is derived, and the bi-level problem is reformulated as the mix-integer quadratic programming problem. The simulation results demonstrate that the proposed bi-level programming can not only reduce the operational cost of the power system, but also increase the profit of the electrolytic aluminum plant when it provides DR services.