Study on medium and long-term optimal dispatching rules for cascade hydro-wind-photovoltaic system crossing sections

Abstract

The topic of giving full play to the flexible regulation of hydropower and the optimal allocation of power grid resources, optimising the complementary scheduling mode of the new power system with renewable energy as the main body, and reducing the difficulty of grid scheduling decision-making, so as to promote the consumption of wind and wind power and ensure the safe and stable operation of the grid urgently needs in-depth research. This paper was written to address the problem of joint optimal scheduling across transmission cross sections under a new type of power system to provide a decision-making basis for the scheduling of gradient reservoirs. In this paper, a medium-and long-term optimal scheduling model is constructed with the objective of maximising the generation capacity of the terraced hydropower station and minimising the fluctuation of the cascade hydro-wind-photovoltaic complementary system output in the dry period section based on the annual scheduling task of backbone reservoirs and the smoothness of system output. Taking the 70-year long series operation data of Yalong River clean energy base as information, PSO-POA algorithm is used to solve the model. According to the result of optimisation calculation, the medium-and long-term scheduling function of backbone reservoirs is extracted by threshold regression method. The result show that the mean values of the coefficient of determination(R²) of the constructed monthly dispatch functions for the Lianghekou station, Jinping Ⅰ station and Ertan station are 0.869, 0.868 and 0.874, respectively, which have a better fitting effect on the whole, and can provide operational decision-making support for reservoir dispatching.

Keywords

hydro-wind-photovoltaic complementary system / optimised dispatching model / dispatching function / threshold regression