Utilising digital light processing and compressed sensing for photo-current mapping of encapsulated photovoltaic modules
Photocurrent mapping can provide useful spatial information about the electrical and optical properties of a photovoltaic (PV) device under actual operating conditions. Although it is a well-established technique for PV cells, direct current mapping measurements of PV modules is impractical and time-consuming to be applied. One has to mechanically shade specific cells of the PV module or destructively access the cell to be measured. In this work, non-destructive, automated current mapping of encapsulated PV modules is demonstrated. A commercial Digital Light Processing (DLP) projector is utilised in order to apply compressive sampling for current mapping of PV modules. This method is non-destructive, cost effective and significantly fewer measurements are needed for acquiring a current map compared to raster scanning methods. When applying compressive sampling, a series of patterns is projected on the sample, the current response is measured for each pattern and the current map is acquired using an optimisation algorithm. Specific shading strategies, voltage bias settings and I-V curve details are investigated for optimised compressive sampling.
This work was funded through the European Metrology Research Programme (EMRP) Project 16ENG02 PV-Enerate. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. This work is co-funded by the UK National Measurement System.
- Mechanical, Electrical and Manufacturing Engineering