In the rapidly evolving landscape of energy systems, the integration of renewable energy sources has brought about unprecedented challenges and opportunities. Among these, ensuring frequency stability in power grids has emerged as a critical concern, particularly with the increasing penetration of renewable energy. A groundbreaking study led by Jiaxin Wang from the Department of Electrical Engineering at Tsinghua University in Beijing, China, published in the journal ‘iEnergy’ (translated from Chinese as ‘Energy’), sheds new light on how energy storage can be strategically planned to mitigate frequency-related issues in power grids.
The research focuses on the complexities introduced by cross-regional high voltage direct current (HVDC) systems, which facilitate the transmission of renewable energy over long distances. While these systems are instrumental in bringing renewable power to the grid, they also pose significant risks. “HVDC failures can result in large disturbances to the receiving power grids, leading to critical frequency security problems,” Wang explains. The high penetration of renewable energy further exacerbates the issue by reducing system inertia and damping coefficients, making frequency nadirs— the lowest points of frequency deviation after a disturbance—more pronounced and potentially triggering low-frequency protection mechanisms.
To address these challenges, Wang and his team developed a novel energy storage planning model that considers both the center-of-inertia (COI) frequency and nodal frequency security constraints. The model aims to determine the optimal capacities and locations of energy storage systems based on year-round operations, ensuring robust frequency stability.
The study employs a hybrid data-model driven approach to generate nodal frequency security constraints for a wide range of operation modes. This method combines historical data and predictive modeling to create a comprehensive framework for energy storage planning. “By integrating both COI and nodal frequency constraints, we can achieve a more resilient and secure power grid,” Wang notes.
The research was validated through case studies on a modified RTS-79 test system and a 1089-bus power system in Jiangsu, China. The results demonstrated the effectiveness of the proposed methods in enhancing frequency security and optimizing energy storage deployment.
The implications of this research are far-reaching for the energy sector. As renewable energy penetration continues to grow, the need for advanced frequency control mechanisms becomes increasingly urgent. The findings by Wang and his team offer a promising solution for ensuring the stability and reliability of power grids, which is crucial for the commercial viability of renewable energy projects.
Energy storage planning that accounts for both COI and nodal frequency constraints can significantly reduce the risk of frequency-related outages, thereby enhancing the overall resilience of the grid. This, in turn, can lead to increased investor confidence and accelerated deployment of renewable energy infrastructure.
Moreover, the hybrid data-model driven approach proposed in the study can be adapted to various power systems, making it a versatile tool for energy planners and operators worldwide. As the energy landscape continues to evolve, such innovative solutions will be instrumental in shaping a sustainable and secure energy future.
The research published in ‘iEnergy’ marks a significant step forward in the quest for frequency stability in modern power grids. By leveraging the strengths of energy storage and advanced planning methods, the energy sector can overcome the challenges posed by renewable energy integration and pave the way for a more resilient and sustainable energy system.