Updates of IEEE 519-2022 than IEEE 519-2014 • • • Title was changed from ‘Recommended Practice and Requirements’ to ‘Standard’. The constraints on even-order harmonic currents have been loosened. Prior to the current limit tables, all even-order harmonics were restricted to a maximum of 25% of the individual harmonic limits. o For h<=6 -> Limits have increased from 25% to 50% of the individual limits shown in the tables. o For h>6 -> Limits have increased from 25% to 100% of the individual limits shown in the tables. The scope has been expanded to include installations of distributed energy resources (DER) and/or inverter-based resources (IBR) that point users toward IEEE standards 2800 or 1547 for current distortion restrictions in the event that the total site's rated generation exceeds 10% of the yearly average load demand. In the standard, Figure presents a Decision Tree for determining if IEEE Std 519 current limitations are applicable at the PCC. Installation Type DER or IBR added with the loads DER or IBR added with the loads Without DER or IBR Annual Average Load Demand (%) Less than 10% Standard Apply to IEEE 519 Higher than 10% IEEE 1547 or IEEE 2800 - IEEE 519 IEEE 1547 In IEEE 1547 instead of THD the new term TRD comes into play. TRD is Total Rated-Current Distortion and is the total root-sum-square of the current distortion components. %TRD = √(Irms – I1) /Irated * 100% I1 is the fundamental current as measured at the reference point of applicability (RPA). Irated is the distributed energy resource (DER) rated current capacity (transformed to the RPA when a transformer exists between the DER unit and the RPA) Irms is the root-mean-square of the DER current, inclusive of all frequency components, as measured at the RPA.