A Linear Identification of Diode Models from Single $I$– $V$ Characteristics of PV Panels

TLDR

The study introduces a novel method for identifying diode model parameters from photovoltaic panels’ I‑V characteristics. The method models the diode as the output of a dynamic system, links its parameters to the system’s transfer function via Laplace transform, and identifies them using a simple integral‑based linear least‑squares approach, with comparisons to Lambert‑W and evolutionary algorithms. Indoor flash tests confirm the method’s accuracy and effectiveness, while outdoor module tests demonstrate its capability for online monitoring and diagnostics.

Abstract

This paper presents a novel approach on diode model parameter identification from the I- V characteristics of photovoltaic panels. Other than the prevailing methodology of solving a group of nonlinear equations from a few points on the I-V curve, the proposed methodology views the diode model as the equivalent output of a dynamic system. From this new viewpoint, diode model parameters are linked to the transfer function (after Laplace transform) of the same dynamic system whose parameters are then identified by a simple integral-based linear square. The indoor flash test shows the accuracy and effectiveness of the proposed method, and outdoor module testing shows its ability of online monitoring and diagnostics. Comparisons to the methods of Lambert W function and evolution algorithms are also included.