Assessing Inverter-Based Resources Modeling Gaps in Commonly Used Short-Circuit Programs
Zheyuan Cheng, Trupal R. Patel, Juergen Holbach, Matthew J. Reno, Christopher Weldy, Thanh Nguyen, Yazid Alkraimeen · 2025
Future bulk power systems are expected to operate with a high penetration of inverter-based resources (IBR). This is anticipated to fundamentally change the system's short-circuit behaviors and demand a change in existing transmission line protection settings or schemes. Phasor-domain short-circuit programs (e.g., ASPEN OneLiner and APA (formerly PSS${ }^{(1)}$CAPE)) remain the mainstream tools for developing protection settings. However, the system protection community has shared concerns about the accuracy of IBR models in short-circuit programs. This report compares the performance of existing generic IBR models in short-circuit programs with detailed electro-magnetic transient (EMT) models provided by several different IBR manufacturers in PSCAD, to quantify the short-circuit program's IBR model accuracy, assess their ability to replicate individual IBR controls such as negative sequence current injections, and identify specific gaps in the existing generic phasor-domain IBR models that are currently available.