Participation of energy storage batteries in primary frequency control for power grid considering dynamic frequency inertia characteristics

In a rapidly transforming global energy landscape, renewable sources like wind and solar are increasingly central to power generation, but they bring new challenges. Unlike traditional power plants, which provide inherent stability through mechanical inertia, renewable energy systems lack this capability, leaving grids vulnerable to frequency fluctuations. To address this, researchers from Hunan University, Shanghai Jiao Tong University, Hunan City University, and the National Electric Power Dispatching and Control Center, China, have developed a dynamic strategy to enhance the role of energy storage systems in stabilizing power grids. Their finding was recently published in Journal of Shanghai Jiao Tong University.

Their innovative approach focuses on enabling energy storage batteries to participate in primary frequency regulation—critical for maintaining grid stability during supply and demand imbalances. By leveraging the potential of these batteries, the team aims to fill the gap left by the absence of traditional inertia in modern renewable grids.

"Our goal was to use energy storage systems to support frequency stability, something that's been missing in grids dominated by renewable energy," said Cai Zhenhua, lead author from Hunan University and Hunan City University.

The solution lies in the use of Virtual Synchronous Generators (VSGs) combined with advanced control strategies that dynamically adjust the system’s response based on real-time grid conditions. The researchers developed a three-part strategy: an additional active power module that allows energy storage batteries to generate stabilizing power, a variable rotor inertia control system that adjusts the inertia in real time, and an output feedback model predictive control system that uses data to predict and compensate for frequency deviations.

"In traditional grids, large spinning turbines help stabilize frequency, but we're now mimicking that behavior using energy storage systems," explained Li Canbing, co-author and professor at Shanghai Jiao Tong University.

Simulations showed that this strategy significantly improved grid stability, outperforming existing methods by reducing maximum frequency deviations and enhancing the system's ability to manage sudden changes. This breakthrough is particularly relevant as grids transition to renewable energy sources, which are more variable than traditional fossil fuels.

Next, the team plans to apply this strategy to larger grid systems and explore its adaptability to other renewable sources. Their work highlights the crucial role energy storage systems can play in ensuring grid stability in the face of increasing renewable energy integration, marking a key step towards a cleaner, more stable energy future.