Recent research led by Fang Liu from the State Grid Henan Electric Power Company Jiaozuo Power Supply Company has introduced a promising optimization strategy for photovoltaic energy storage systems, particularly focusing on the operation of virtual synchronous generators (VSGs). Published in the journal Heliyon, this study addresses a common challenge in energy storage: the impact of random load interference on the lifespan and efficiency of storage devices.
The research proposes a selective input/output strategy that significantly enhances the operational life of photovoltaic energy storage systems. This strategy includes two distinct operating modes and a power coordination control method designed for VSGs. By implementing a selective VSG input strategy based on the magnitude of disturbances, the researchers developed a method that determines the optimal timing for VSG input. This is achieved using an offline model equation, complemented by an online method that adjusts to variations in disturbance frequency. As Liu notes, this allows for a “selective VSG startup method, allowing the grid to prioritize the utilization of the generator’s physical inertia.”
Another key aspect of the research is the dynamic VSG exit strategy, which is designed to mitigate secondary oscillations during the frequency recovery phase after grid disturbances. This is particularly vital since fluctuations in the grid can adversely affect the lifespan of energy storage systems and slow down frequency recovery.
The implications of this research are significant for the energy sector. By reducing the capacity of charge and discharge cycles by 37.82% compared to traditional strategies, the proposed method not only lowers operational costs but also enhances the reliability of energy storage systems. This is crucial as the demand for renewable energy sources continues to grow, and effective energy storage solutions become increasingly important for grid stability and efficiency.
The authors validated their approach through computer simulations and semi-physical experiments using the NI-PXI + LabVIEW platform, demonstrating its effectiveness in real-world applications. By optimizing the selective start of VSGs and improving energy storage life, this research paves the way for more sustainable and cost-effective energy solutions.
As the energy sector looks to innovate and adapt to the challenges posed by renewable energy integration, Liu’s findings offer a valuable opportunity for companies to enhance their energy storage systems, ultimately contributing to a more resilient and efficient energy grid.
