Long-Term Equilibrium Operational Plan for Hydro-PV Hybrid Power System Considering Benefits, Stability, and Tolerance

Abstract

Due to the volatility, intermittency and, randomness of photovoltaic (PV) power output, hydropower is utilized as a complementary power source. The largest grid-connected hydro-PV power station, the Longyangxia project, is operational and located in northwestern China. The annual power station operational plan assists in making appropriate annual electricity purchasing and sales contracts and in economically benefiting the enterprise. Focusing on the Longyangxia project, this study proposes using a multiobjective optimization model to make a long-term equilibrium operational plan for a hydro-PV power system while simultaneously considering the benefits, stability, and tolerance of the power grid. The Non-dominated Sorting Genetic Algorithm version II (NSGA-II) is adopted to optimize the model, and the Pareto fronts for different hydrological years are presented. The results demonstrate the competitive relationships between the objectives, but there are distinct points where the relationships are more in line with one another. The inflection points are identified, based on the analysis, as the recommended solutions for operating the hydro-PV power system, and the corresponding reservoir operational schemes are also presented.