Verification of Simulator Concentration Level and CPV Cell Linearity

The linearity of the short circuit current (Isc) of CPV cells over several order of magnitude of irradiance is frequently assumed. Hence, in a self-reference calibration method, the ratio of Isc at concentration to its value at 1 sun is frequently used to estimate the concentration ratio. However, this assumption may not be in all cases strictly true, and is not appropriate for calibration purposes. A method of CPV cell calibration has been described previously [1], employing standard reference cells combined with neutral density (ND) filters to enable simultaneous cell and irradiance measurement up to high intensity levels. The method presented, while shown to be satisfactory in principle, had the limitation that the reference cells used have been verified to be linear over only approximately one order of magnitude. This meant that more than one ND filter has to be used to cover a suitably large range of intensities, and indeed results did suggest that at the point of change over some systematic error was introduced. The reference cell and ND filter combination used also proved bulky leading to increased uncertainty in the irradiance levels at the device compared to the reference. In this paper we present an improvement to the measurement setup, employing a new reference device, and a new set of ND filters. Results of linearity verification and measurements on CPV cells are also presented.

KENNY Robert;  AITASALO Tuomas;  GALLEANO Roberto; 

2012-02-22

American Institute of Physics

JRC61752

978-0-7354-0979-8,   

0094-243X,   

http://link.aip.org/link/doi/10.1063/1.3658327,    https://publications.jrc.ec.europa.eu/repository/handle/JRC61752,   

10.1063/1.3658327,