Complementary operation of a small cascade hydropower station group and photovoltaic power stations

Abstract

Complementation with hydropower is an important solution to solve the problems of grid connection and consumption of photovoltaic generation. Considering the randomicity of photovoltaic output and runoff, hydropower station with good regulation capability is often used as a complementary power source of photovoltaic generation. However, there are only a small number of regulatory hydropower stations, which is difficult to meet complementary requirements of widely distributed photovoltaic power stations. The present study aimed to explore the feasibility of using a small cascade hydropower station group as the only complementary power source for photovoltaic generation. Based on electric energy production and output fluctuation, this study constructed a hydro-photovoltaic complementary operation model with dual-objectives of maximization of average capacity factor of the system and load rate of power generation. An algorithm coupling flower pollination algorithm with progressive optimality algorithm (coupling algorithm) was put forward to obtain solutions. The simulation results of the model showed that the fluctuation in joint operation mode is significantly lower than that in single operation mode, and the comprehensive target value on sunny day calculated by the coupling algorithm is 2.53% and 2.16% higher than the results of flower pollination algorithm and progressive optimality algorithm, respectively, verifying the reliability and rationality of the model and the algorithm.