Compliance Analysis of Series Arc-fault in AFCI- Equipped Inverters in Accordance with IEC 63027

The National Institute of Metrology, Quality and Technology (Instituto Nacional de Metrologia, Qualidade e Tecnologia - INMETRO) introduces that, starting in 2024, all photovoltaic (PV) inverters sold in the Brazilian market must incorporate an Arc-Fault Circuit Interrupt (AFCI) function into their systems. These inverters are required to comply with the IEC 63027:2023 (Photovoltaic power systems DC arc detection and interruption) standard. Considering this, the Electrical Engineering Laboratory at Mackenzie Presbyterian University (Universidade Presbiteriana Mackenzie UPM) conducted a series of arc-faults tests on three inverters available in the market, following the IEC 63027 standard. Each of the three inverters underwent a total of 32 arcs, considering number of Maximum Power Point Tracking (MPPT) ports, different impedance topologies, arc position in the PV system, and maximum values of voltage and current. The experiments revealed that two of the three inverters are not capable of meeting the international standard for detecting and interrupting series arc-faults, highlighting the need evaluation of PV inverter sold in the Brazilian market. During the analysis, it was noted that for certain parameters proposed by IEC 63027, there is a gap of information regarding evaluation of the data relating to arc self-extinguish or actual AFCI intervention. It is show that this scenario can raise a concern: the possibility exists for an inverter meet the international standard without implementing an effective AFCI technology. The 96 tests conducted were compared in terms of arc detection time and arc energy. The data were analyzed and compared with respect to the phenomena of arc self-extinguishing and the operation of the AFCI. Suggestions for enhancements to the IEC 63027 standard were provided