The analyses of the performance of a complete photovoltaic system require precisemeasuring equipment in order to obtain reliable comparative results. This paper presents acomputer-based instrumentation system suitable for a characterization of photovoltaicconversion chains. Consisting in a data acquisition stage, a data processor, photovoltaicgenerators and power conditioners, the system evaluates the respective efficiency ofmaximum power point tracker (MPPT) and power conditioner. The efficiency of unknown MPPTfunctions is estimated with great accuracy by means of an extremum control-based MPPT usedas a reference. Efficiency evaluations of two photovoltaic battery chargers during 4 daysillustrate the estimation procedure and the system test facilities.
