Research on Multi-Time-Scale Optimal Scheduling of Hydro–Solar Complementation in the Shuoqu River Basin

Abstract

The integration of high shares of renewable energy into the power grid poses significant challenges to the stable operation of power systems. Hydropower, owing to its rapid response capability and reservoir regulation capacity, can effectively mitigate the volatility and randomness associated with photovoltaic power output. This study adopts the “hydro-regulated photovoltaic generation” approach as its core methodology. First, a six-dimensional complementary comprehensive evaluation indicator system is established, and the weights of each indicator are determined using the Analytic Hierarchy Process. Second, tailored to long-term and short-to-medium-term forecasting requirements, the quantile mapping method and the ARIMA–Prophet model are employed to forecast solar and hydroelectric resource. Finally, based on the Guwa Hydropower Station, a long-term–medium-term–short-term multi-objective optimal dispatch framework is developed. The NSGA-II algorithm is utilized to perform multi-objective optimization targeting power generation and resource utilization efficiency. The results demonstrate that, after long-term optimization, power generation increased by 6.34% compared to the non-optimized scenario; medium-term optimization achieved monthly power generation efficiency improvements of 11.45% during the high-water period; and after short-term optimization, the daily output power fluctuated cyclically between 45 and 129 MW, while the overall output remained smooth.