Aurora was appointed by Windcare to undertake a transformer energisation study for a new wind turbine 11kV connection, to ensure that the voltage sag was within the ENA P28 limits.
Aurora was able to perform the study using simple Excel based analysis techniques, instead of having to resort to complex electromagnetic analysis using PSCAD; and despite the voltage dip exceeding the nominal 3% limit set in ENA P28, Aurora was able to convince the DNO that the lower limit of 10% as set in the distribution code was acceptable and that Pre-Insertion Resistors (PIRs) were not necessary.