As the energy landscape shifts towards a greater reliance on inverter-based resources (IBRs), understanding the dynamics of power grids becomes increasingly critical. A recent study published in ‘IEEE Access’ sheds light on how the integration of IBRs, particularly those utilizing droop-based grid-forming (GFM) control, affects inter-area oscillation modes in bulk power grids. This research, led by Shuchismita Biswas from the Pacific Northwest National Laboratory (PNNL), highlights the intricate relationship between the location of IBRs and the behavior of inter-area oscillation modes, which are essential for maintaining grid stability.
The study reveals that the displacement of traditional synchronous machines by IBRs can significantly alter the properties of these oscillation modes. “The changes in oscillation modes are highly dependent on where synchronous machines are removed or IBRs are added,” Biswas emphasizes. This finding is crucial for electric utilities as they navigate the complexities of transitioning to more renewable energy sources. The ability to predict and mitigate these changes through careful tuning of GFM control parameters offers a pathway to maintain grid reliability.
One of the key insights from the research is the potential to adjust two specific GFM inverter control parameters: the active power-frequency droop coefficient and the time constant of the active power measurement low-pass filter. By fine-tuning these parameters, utilities can enhance the damping of inter-area oscillations, thereby ensuring smoother operations as the grid evolves. This capability is particularly relevant as regions across the United States and globally move towards ambitious renewable energy targets, often necessitating a shift from conventional generation methods.
Biswas’s team validated their analytical conclusions through dynamic simulations of the IEEE 39-bus benchmark system and the 2031 heavy-winter planning model of the US Western Interconnection. These simulations provide a robust framework for utilities to assess potential impacts in their specific operational footprints. “Understanding which inter-area modes will continue to be a concern in an IBR-dominated future is vital for our energy infrastructure,” she notes.
The implications of this study extend beyond theoretical analysis. As electric utilities prepare for a future with increasing IBR penetration, the findings could drive significant investments in grid technology and infrastructure. By identifying areas where the replacement of synchronous machines could lead to instability, utilities can prioritize upgrades and enhancements, thereby safeguarding energy reliability and reducing the risk of outages.
In an era where the energy sector is increasingly scrutinized for its operational resilience and adaptability, research like Biswas’s plays a pivotal role in shaping how utilities approach the challenges posed by a rapidly changing grid. As the industry moves forward, the insights gained from this study will be instrumental in guiding interconnection studies and ensuring that the transition to renewable energy is both effective and sustainable.
For further insights, you can explore the work of Shuchismita Biswas at the Pacific Northwest National Laboratory.
