Automatic data acquisition system for testing photovoltaic conversion chains performances in real conditions

Abstract

The analyses of the performance of a complete photovoltaic system require precise measuring equipment in order to obtain reliable comparative results. This paper presents a computer-based instrumentation system suitable for a characterization of photovoltaic conversion chains. Consisting in a data acquisition stage, a data processor, photovoltaic generators and power conditioners, the system evaluates the respective efficiency of maximum power point tracker (MPPT) and power conditioner. The efficiency of unknown MPPT functions is estimated with great accuracy by means of an extremum control-based MPPT used as a reference. Efficiency evaluations of two photovoltaic battery chargers during 4 days illustrate the estimation procedure and the system test facilities.