Inverter-Based Resource Penetration: How Much Is Too Much? An Attempt To Answer The Question of What Constitutes High Penetration of Ibr Resources

A question that pops up whenever the topic of high penetration of Inverter-Based Resources is brought up is, what exactly constitutes high penetration of IBR resources in a power system? Is there a way to quantify what constitutes high penetration of IBR? Should it be quantified in terms of available inertia in the system? Is it static as in defined for the system once the ratio of IBR vs other resources is set or should it be dynamically evaluated considering the dynamics of the network? Should grid forming IBR be evaluated differently from grid following IBR when it comes to IBR penetration? How does the ability of certain IBR to produce synthetic inertia affect these evaluation criteria? Should this question be answered in relation to power system stability criteria? Is this question even relevant given that there are networks already where there is 100% of power generation from IBR during certain periods? What happens when networks only have IBR and no more synchronous inertia? This paper is an attempt to answer some of the questions above with emphasis on trying to establish a criterion or set of such criteria for determining what constitutes high penetration of IBR resources in a power system.