Inverter-based resources (IBR) do not exhibit the same behavior as conventional machines. Attempting to test protection devices using average models or custom-built reverse-engineered controllers in the RTDS is not a viable solution. Each IBR manufacturer can have significant performance differences, and firmware or set point changes can significantly alter the behavior.
SEL has recently explored two methods from RTDS: GTSOC and GTDI controlling the universal converter model (UCM). The GTSOC method is a new hardware platform developed by RTDS that allows an inverter manufacturer to cross-compile their code to a native format to provide the firing pulses; thereby, eliminating the need to “guess” how their controller performs. The GTDI card approach allows for the physical inverter board to be interfaced to provide the firing pulses. While this sounds straightforward, there can be significant modifications required to the control board to make this work.
This presentation will cover the model and test setup, the challenges encountered, and the results for various faults to demonstrate the performance for the conventional source, the GTSOC UCM model, and the GTDI UCM model. From these results, it will be demonstrated that IBRs do not perform like conventional sources, that even between different manufacturers the results are not the same, and that we truly are at the mercy of the programmer.
Jordan Bell, Schweitzer Engineering Labs