Preen ARLC Series

Anti-islanding testing to IEEE 1547 and 1547.1 requires a load bank capable of simulating a precise local balance between generation and load — the exact condition that would allow a distributed energy resource to continue operating undetected after disconnection from the utility grid. Preen's ARLC Series is purpose-built for this: an automated RLC load bank with independently controlled resistive, inductive, and capacitive elements, available in 30kW, 60kW, 120kW, and 250kW base models.

The independently switched R/L/C loads let the ARLC simulate all four IEEE 1547.1 islanding test conditions — frequency drift, voltage shift, combined drift, and the hardest-to-detect matched-power islanding condition, where load and generation are balanced closely enough that frequency and voltage stay within normal operating limits. Reproducing this matched-power condition accurately and repeatably is the real test of an anti-islanding protection scheme, since a poorly balanced load bank can make islanding either too easy or too hard to detect, giving a misleading pass or fail result.

The modular design supports parallel connection for test programs needing more than a single unit's capacity, and pairing the ARLC with Preen's PAS or ADG power supplies and automation software builds a complete anti-islanding test platform scaling up to 2000kW — relevant for utility-scale inverter and grid-tied generation qualification where test capacity needs to match the actual generation asset being certified.