Effects of Operating Range of Hydropower Units in Hydro-Wind-PV Hybrid System Considering Benefit, Risk and Stability

Large-scale grid integration of wind and PV power is important for achieving decarbonized development. This integration requires frequent regulation of flexible power sources for complementary operations such as hydro-wind-PV hybrid system (HWPHS). However, most of the existing operational range of hydropower units is relatively limited, making it difficult to provide sufficient flexibility to cope with the uncertain wind and PV power. This can result in hydropower units being forced to operate in the risky part-load region. To analyze and evaluate the effects of different operating ranges of hydropower units in hybrid system, this work proposes an evaluation model for HWPHS via five indicators considering benefit, risk and stability. Moreover, the model is applied to a large hybrid energy base in China. The results show that the proposed model and method provide support for the evaluation and decision-making regarding the stable operation range of hydropower units in the transformation and upgrade of hybrid energy systems.