Funding Program: SuNLaMP
SunShot Subprogram: Systems Integration
Location: Oak Ridge National Laboratory, Oak Ridge, TN
SunShot Award Amount: $2,200,000
Awardee Cost Share: $107,853

As the number of solar photovoltaic (PV) installations continues to grow exponentially, one of the major challenges to grid stability will be mitigating decreasing system inertia and deteriorating frequency response. Preliminary independent studies on two North American interconnections have already demonstrated that the overall frequency response will deteriorate significantly with increasing renewable generation. This project will investigate the frequency response and system inertia impacts with high PV penetration levels for all three major interconnections, namely the Eastern Interconnection, Western Interconnection, and the Electric Reliability Council of Texas.

Approach

Researchers will start with the current dynamic models of all three major interconnections that have been validated using a unique database of system disturbances from the North American Frequency Monitoring Network. The first phase of this project will develop a wide range of PV penetration scenarios based on the measurement-validated grid model, and realistically projected PV distribution for each interconnection. Next, the project team aims to achieve a thorough understanding of the frequency impact of high PV penetrations at both the interconnection and local levels using the developed scenarios. Finally, the project team will develop and validate solutions to improve low system inertia and reduced frequency response. Upon completion, this project will quantify frequency response changes as PV penetration increases from the current day value to the SunShot Vision Study 2030 and 2050 predictions and beyond.

Innovation

Considering the complicated nature of the North American interconnections, no existing small-size IEEE models or significantly-reduced grid models can replicate these interconnections to a practical extent. Even today’s full-scale interconnection models are known to poorly reflect measured frequency responses, so simulations using these models cannot provide meaningful guidance. This project will allow researchers to accurately quantify the negative impact of high PV penetration levels on North American power grid frequency stability using dynamic simulations using the measurement-validated interconnection models.