Influence of Capacity Configuration on Stability of Hydropower-Photovoltaic Hybrid Energy Systems

Hydropower (HP) and photovoltaic (PV) hybrid energy systems could reduce the impact and influence of PV output power randomness and volatility on the power grid. To study the stability of the HP-PV hybrid energy system operating under different scenarios, in this paper, we first establish a mathematical model of the system. Theoretical analysis and numerical simulation methods are then adopted to obtain the stability region and stability margin of the system with different PV shares. Besides, the preferred operating range of the HP system is explored. The results show that: (1) the system stability decreases with the increase of the PV share in the hybrid energy system, and the preferred HP operating range shrinks; (2) the basic law in which the PV share and the HP control parameters jointly affect the system stability is revealed. This work provides a theoretical basis for subsequent physical model experiments in the future.