UL Solutions Test Report Summary
Flyers
Keysight enlisted UL Solutions to compare two IEEE 1547.1-2020 unintentional-islanding test methods on the same distributed energy resource (DER): a traditional, manually-tuned physical RLC load bank (Method A) and Keysight’s automated PHIL-based approach using the SL1200 Series Grid Emulator and SL1221A PHIL Anti-Islanding Software (Method B).
What UL Solutions Tested:
- The same three-phase DER with the same parameters for both methods.
- Five representative IEEE 1547.1 Category B unintentional-islanding cases were used: 1B, 4B, 5B, 7B, and 9B as a representative set of the IEEE 1457 test requirements.
- The cases covered different power levels, reactive power modes, active power modes, and load conditions from 95% to 105%.
What UL Solutions Found:
- Both methods are valid IEEE 1547.1-2020 test approaches.
- Side-by-side test data shows similar results between traditional RLC load-bank method and Keysight's PHIL-based method.
- Automated PHIL tuning is reasonably expected to improve precision and repeatability.
- Both methods met the IEEE 1547 clearing-time requirement.
- PHIL automation reduced test execution from weeks to less than one day.
You can also download the full UL report here.