Description of Inverter Penetration SCR (IPSCR) Metric for Quantifying System Strength in Large Networks
A new collective short circuit strength metric is proposed which attempts to provide relative system strength quantification for large power grids with many Inverter Based Resources (IBRs) connecting. The key concept of this new metric, termed Inverter Penetration Short Circuit Ratio, or IPSCR, is that the short circuit strength which is available within a certain region may come from a combination of conventional sources and IBRs. As the proportion of the generation mix moves towards IBRs, the IPSCR calculated will fall, indicating an overall weakened system. This metric has been tested in the ATC system with some success.
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