Loughborough University
Browse
GKoutsourakis - EU-PVSEC 2015 Abstract.pdf (294.96 kB)

Fast current mapping of photovoltaic devices using compressive sampling

Download (294.96 kB)
conference contribution
posted on 2016-03-04, 12:14 authored by George Koutsourakis, Xiaofeng Wu, Matt Cashmore, Simon R.G. Hall, Martin BlissMartin Bliss, Tom BettsTom Betts, Ralph Gottschalg
Light Beam Induced Current (LBIC) measurements are a useful tool in photovoltaic (PV) device characterisation for accessing the local electrical properties of PV devices. The main disadvantage of a typical LBIC system is measurement time, as a raster scan of a typical silicon solar cell can last several hours. The focus of this paper is the reduction of LBIC measurement time by means of compressed sensing (CS). The CS-LBIC system described in this paper can theoretically reduce measurement time to less than 25% of that required for a standard LBIC raster scan. Measurement simulations of a CS-LBIC system are presented as well as a practical demonstration using a digital micro-mirror array, which further reduces the measurement time by an order of magnitude. Instead of a raster scan, the PV device under measurement is sampled by a series of patterns and the current map is reconstructed using an optimization algorithm. Simulations of CS-LBIC measurements using the 2D spatially-resolved PV-Oriented Nodal Analysis (PVONA) model developed at CREST are used as a tool to explore the capabilities and verify the accuracy of this measurement technique as well as its ability to detect specific defects, such as cracks and shunts. Simulation results confirm that the CS sampling theory can be applied as an effective method for significantly reducing measurement time of current mapping of PV devices. An initial CS-LBIC system prototype has been built at the National Physical Laboratory (NPL) and measurements of small area devices (1cm x 0.8cm) using this system are given. The current maps are created using a Digital Micromirror Device (DMD) kit as a pattern generator. The response time of the micro mirror array is less than 20μs. This is another factor in the reduction of measurement time, as the movement time of an x-y translation stage is considerably slower. Initial measurement results show that current maps of PV cells can be acquired with 75% fewer measurements which, combined with the fast response of the pattern generator, can reduce LBIC measurement time by an order of magnitude.

History

School

  • Mechanical, Electrical and Manufacturing Engineering

Published in

31st European PV Solar Energy Conference

Pages

29 - 29 (6)

Citation

KOUTSOURAKIS, G. ...et al., 2015. Fast current mapping of photovoltaic devices using compressive sampling. Presented at the 31st European PV Solar Energy Conference, Hamburg, Germany, 6th November 2015, pp. 29-34.

Publisher

WIP

Version

  • AM (Accepted Manuscript)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Publication date

2015

Notes

This is a conference paper.

ISSN

2196-100X

Language

  • en

Location

Hamburg, Germany

Usage metrics

    Loughborough Publications

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC