In the rapidly evolving landscape of power grid technology, a groundbreaking study led by Markel Zubiaga from the Department of Electronic Technology at the University of the Basque Country (UPV/EHU) is set to redefine how we approach grid stability and the integration of renewable energy sources. Zubiaga’s research, published in the journal Applied Sciences (translated from Spanish as Applied Sciences), delves into the capabilities of grid-forming inverters in counteracting low-frequency oscillations, a critical challenge as power grids increasingly rely on inverter-based resources (IBRs).
As traditional synchronous generators are phased out in favor of IBRs, the overall inertia of power grids is diminishing. This shift, while beneficial for integrating renewable energy, poses significant risks to system stability, particularly in terms of frequency and small-signal rotor angle stability. Low-frequency oscillations (LFOs) are becoming more prevalent, threatening the reliability of power distribution and the stability of the grid.
Zubiaga’s research focuses on grid-forming (GFM) inverters, which offer a promising solution to these challenges. Unlike conventional grid-following inverters, GFM inverters provide inherent inertia and directly influence small-signal rotor angle stability. However, integrating power oscillation damping (POD) algorithms into these inverters presents unique challenges, particularly when using active-power-based POD (POD-P) methods.
“One of the key findings of our study is the need to consider not just the impact of POD controls on the grid, but also their effect on the properties of the GFM devices themselves,” Zubiaga explains. “This dual perspective is crucial for ensuring that the inherent capabilities of GFM inverters, such as inertia and damping, are preserved while enhancing grid stability.”
The study introduces a theoretical framework using the network frequency perturbation (NFP) approach to assess the impact of POD controls on GFM devices. This method allows for a detailed analysis of the device-level behavior during grid disturbances, independent of the grid dynamics. By validating their theoretical findings through extensive experimental testing, Zubiaga and his team have demonstrated the effectiveness of a simple POD-P control method for GFM controllers.
The implications of this research are far-reaching for the energy sector. As the integration of renewable energy sources continues to grow, the need for stable and reliable power grids becomes ever more critical. GFM inverters, with their inherent inertia and damping capabilities, offer a viable solution to the challenges posed by LFOs. By optimizing POD-P algorithms and ensuring the preservation of GFM properties, energy providers can enhance grid stability and reliability, paving the way for a more sustainable energy future.
The commercial impact of this research is significant. Energy companies investing in GFM technology can expect improved grid performance, reduced downtime, and enhanced reliability. This, in turn, can lead to cost savings and increased customer satisfaction. Moreover, the insights gained from this study can inform the development of new grid codes and standards, ensuring that future grid-forming technologies meet the highest levels of performance and reliability.
As the energy sector continues to evolve, the work of Zubiaga and his team at the University of the Basque Country serves as a beacon of innovation and progress. Their research not only addresses the pressing challenges of grid stability but also opens the door to new possibilities in the integration of renewable energy sources. By focusing on the inherent capabilities of GFM inverters and the impact of POD controls, they are shaping the future of power grid technology and paving the way for a more sustainable and reliable energy landscape.