The NERC Industry Recommendation on Inverter-Based Resouce Model Quality Deficiencies dated June 4, 2024 solidifies what I stated in my previous post. I believe at some point this will become mandatory for our entire bulk electric system. I think one of the main concerns was that the faults mentioned were not able to be replicated by the standard RMS softwares used for system planning and protection. The need for accurate system dynamic models and analyzes has arrived. I think this recommendation is a little late in recognizing the complexities in transitioning to Inverter-based resources. Below is an excerpt from the NERC Recommendation: The recommendations in this alert should be implemented by all industry stakeholders to help mitigate systemic modeling deficiencies. Recommendations 1–3 of this alert are general in nature and are intended to provide recommendations for general modeling best practices and should be implemented by all stakeholders using models that perform studies that assess BPS reliability.
We have enjoyed very high reliability in our power system for many decades primarily through synchronous generation (SG). Now with more and more inverter-based resources (IBR’s) replacing the SG we are entering an area of numerous unknowns. IBR’s have been basically designed to go offline during a stressed event on the grid. We have seen numerous instances of this in the last several years. IBR’s are dynamic devices and must be modeled and analyzed with EMT type software such as PSCAD which we have been doing for some time. Now we are beginning to understand that we must add other components of the system such as protective relays on the grid to see how the entire system responds. I have read many articles stating that under stressed conditions to just remove the IBR. This is not nor certainly will not be acceptable moving forward if we want to continue to enjoy the level of reliability that we have enjoyed for many decades. We must model and analyze the system as a whole to better understand how the system responds so that we may continue to enjoy the stable reliable energy supply system. Please feel free to reach out to me to discuss this further.