Photovoltaic (PV) generation is one of the most promising forms of renewable energy generation, with its scale rapidly expanding. However, PV generation is highly sensitive to environmental conditions. To ensure the stable operation of the system, power balance among various generation units, and good output power quality, a hybrid energy storage system is employed to mitigate DC bus voltage fluctuations. This article proposes control strategies for hybrid energy storage system and the DC bus voltage in a PV system during grid-connected operation. Battery and supercapacitor units, due to their complementary energy characteristics, are utilized to suppress the impact of PV power fluctuations on the DC bus when PV power undergoes sudden changes. Additionally, the use of virtual synchronous generators is employed to synchronize the system during grid connection, increasing the system's inertia. Simulation results demonstrate that the proposed strategies effectively and rapidly suppress DC bus voltage fluctuations, thereby enhancing the reliability and stability of the system.

photovoltaic generation,bus voltage,hybrid energy storage system (HESS),virtual synchronous generators