A nonlinear dispatch model and its rapid solution method for large-scale adiabatic compressed air energy storage under variable working conditions

Large-scale adiabatic compressed air energy storage (A-CAES) is a crucial technology for achieving high penetration of renewable energy. The rational formulation of its power schedules is a prerequisite for maximizing its value. However, existing A-CAES dispatch strategies suffer from oversimplified or overidealized models and low solving efficiency. In response, this paper develops a nonlinear dispatch model for A-CAES under variable working conditions, aiming to accurately capture its off-design operating characteristics, and proposes a rapid solution method. Firstly, a nonlinear thermodynamic mathematical model for A-CAES is established under compression, generation, and shutdown conditions, comprehensively considering the variations in ambient temperature, isentropic efficiency, compression ratio, expansion ratio, and temperatures of air reservoir and hot water tank. Then, the aforementioned A-CAES model is integrated into the day-ahead economic dispatch model of power system, which also includes thermal power units and wind farms. Furthermore, to address the challenge of straightforwardly solving the strongly nonlinear dispatch model, an iterative solution method based on the framework of master problem and sub-problem is proposed. Finally, case studies are conducted. The results indicate that the solution time of the proposed method is 412 s, which is only 1 % of the conventional method, while achieving almost identical economic objectives.