Abstract:

With the access of large-scale wind power stations and solar power stations, wind energy and solar energy affect the safe and stable operation of the power system due to the lack of prediction accuracy. Therefore, this paper proposes an optimal scheduling method of the hydro-wind-solar complementary system based on standby flow. Firstly, the standby flow is set according to the available water of each hydropower station based on the inflow flow. Then, the optimal scheduling model based on the standby flow is established with the goal of maximum power generation and minimum variance of residual load, and the standby flow is used to cope with the impact of insufficient wind and solar prediction accuracy. Finally, a case study of the cascade hydropower station and connected wind and solar power stations along the lower Yalong River is carried out. The results show that compared with no standby flow, the power generation efficiency of the multi-energy complementary system with standby flow in typical wet month(June) and typical dry month(December) increases by 0.08% and 1.97%, respectively. And the variance of residual load decreases by more than 40%. The result shows that the setting of standby flow can reduce the imbalance between supply and demand of power system on the basis of ensuring the power generation efficiency, so as to ensure the safe and stable operation of power system.

Key words: wind and solar energy, standby flow, multi-energy complementary system, optimal operation, cascade hydropower station