prBAS IEC TS 61724-2:2027

IEC TS 61724-2:2025 applies to grid-connected PV systems comprising at least one inverter.<br /> The test evaluates the PV system only in conditions where output is unconstrained by limitations in AC power output from the inverters. This document defines a test of a PV system's power performance index (PPI). PPI, defined in IEC 61724‑1, is the ratio of a system's measured power output under test conditions to its expected output at those conditions based on the system's design.<br /> The test is intended to be performed over a short period of typically three to five days and is typically used to satisfy a contractual performance guarantee as part of the final completion of a PV power plant. This second edition cancels and replaces the first edition published in 2016. This edition includes the following significant technical changes with respect to the previous edition:<br /> a) Adapting the document for bifacial PV systems, in accordance with the latest edition of IEC 61724‑1 and current industry practices.<br /> b) Adapting the test procedure to account for the limited times of unconstrained system operation which are now common because of high DC-to-AC ratios (clipping) and interconnection limits (curtailment).<br /> c) Adapting the test procedure to achieve a test that can be performed in a short time of three to five days during favourable conditions.<br /> d) Focusing the document more heavily on the use of modern PV system modelling software to obtain the expected performance of the system under test.<br /> e) Simplifying the mathematical procedure for calculating the test results.<br /> f) Clearly identifying test elections (optional choices to be made in conducting the test) and providing a template for documenting these elections.<br /> g) Clarifying the discussion of the test boundary that separates tested variables from untested variables.<br /> h) Expanding and clarifying the discussion of data filtering.