An Improved Electronic Circuit for Tracing the I-V Characteristics of Photovoltaic Modules and Strings

Abstract

This paper presents an improved electronic circuit for

testing photovoltaic (PV) modules or strings by tracing their I-V and

P-V characteristics. It consists of an electronic fast varying load

based on a power MOSFET controlled by means of an innovative

sweeping gate-source voltage in order to improve the tracing of the

I-V characteristics on an oscilloscope. In order to prevent damage of

data acquisition systems and mainly for use with high voltage PV

strings, galvanic isolation is introduced for the sweeping signal as

well as current and voltage measurements. In spite of this improved

characteristics, the developed electronic circuit keeps the advantages

of low cost and simplicity. Experimental results obtained with the

electronic circuit are presented.