Research On Optimal Configuration Of Hybrid Energy Storage System And Operation Control For Hydro-PV-Storage Complementary System

In order to improve energy supply and improve energy structure,accelerating the development and utilization of clean energy has become a common consensus.In recent years,China’s photovoltaic(PV)industry has developed rapidly.In order to alleviate the impact of randomness and volatility of PV output on power quality and grid security,the research and practice of multi-energy complementary development is very important.In this paper,the research on hybrid energy storage system(HESS)optimization configuration,hydro-PV complementary and hydro-PV-HESS complementary system operation mode of multi-energy complementary system was carried out.The main research contents and conclusions are as follows:(1)Research on the HESS power configuration method for large-scale PV power stations.Through the analysis of the output characteristics of Qinghai Gonghe PV power station,it’s found that the weather factor has a significant impact on the PV output,and then a HESS power configuration method considering PV output characteristics of different weather types for large-scale PV power stations was proposed.The Qinghai Gonghe PV power station was taken as an example and the HESS power configuration scheme is “Super Capacitor 5.65 MW,Vanadium Flow Battery 112.85 MW”.(2)Research on the optimal energy capacity configuration method of HESS for large-scale PV power stations.A multi-objective HESS energy configuration optimization model with minimum life cycle cost and maximum target output satisfaction as objectives was proposed.The Qinghai Gonghe PV power station was taken as an example and the energy capacity configuration results of six different hybrid energy storage combinations were calculated.Through the comparison,the optimal HESS energy configuration scheme was obtained – “Super Capacitor(5.56 MW/0.57MWh)+ Vanadium Flow Battery(112.85 MW/40.61 MWh)”.Besides,a pre-storage operation scheme which can further improve PV output stability was proposed.The results show that the target output satisfaction of the optimal HESS energy configuration scheme is 87.8%,and the pre-storage operation scheme further improves the target output satisfaction to 96.0%,which effectively improves the output stability of the PV power station.(3)Research on hydro-PV complementary and hydro-PV-HESS complementary system operation mode.The hydro-PV complementary and hydro-PV-HESS complementary system operation mode considering the PV output characteristics were proposed,and the optimal target output increment calculation model was established.The hydro-PV complementary and hydro-PV-HESS complementary system operation schemes were obtained with the Banduo hydropower station and the Qinghai Gonghe PV power station as examples.The results show that the hydro-PV complementary operation mode proposed in this paper can reduce the system’s demand for hydropower regulation capability and ensure the stability of the system output.The hydro-PV-HESS complementary system operation mode can effectively reduce the instantaneous random fluctuations of hydropower output and turbine group frequent start and stop times,thus improve stability of hydropower operation.