Abstract: The formation of cascaded hybrid pumped storage through expanding pumped storage units is an effective means to enhance the regulating capacity of traditional hydropower and promote new energy consumption. To consider the correlation and uncertainty of wind and solar power outputs, this paper develops a short-term optimal dispatch model for the operation of a cascaded hybrid pumped storage-wind-solar complementary system, with the Copula function used to construct scenarios for the two outputs combined. Aimed at maximizing the expected return of this system, this model raises the level of large-scale wind and solar grid-connected consumption through introducing a penalty cost for power abandonment. In addition to the conventional hydropower constraints, it accounts for the more complicated hydropower-electricity coupling relationship of the hybrid storage. With the unit as a scheduled object, various new constraints are modeled including the number of fluctuation-regulating runs for a pumped storage unit, the operating states of the hybrid storage station and unit mutual exclusion, and switching between a unit’s pumping and generating conditions. To solve the dispatch model, we construct a Mixed-Integer Linear Programming model by adding new 0-1 variables and auxiliary variables, and use the Java-language Cplex solver. Application in a case study of the Wujiang River cascaded hydropower stations and related wind and solar energy demonstrates that our new dispatch model fully utilizes the flexible regulation capability of the hybrid storage stations, and it succeeds in increasing the utilization rate of the transmission channel, reducing power abandonment, and further enhancing the level of wind and solar energy consumption.

Key words: cascaded hybrid pumped storage power stations, uncertainty of combined wind and solar outputs, multi-energy complementarity, maximum expectation of consortium benefits