| The objective is to measure the IV curve of a concentrator module under reference illumination and temperature. These are the steps for the measurement:
1. The module is positioned on a fixed assembly, which is perpendicular to the light beam. Electrical connections for measuring its voltage and current are made.
2. The module is biased at a given voltage of the IV curve, and then the Xenon flash lamp is triggered. Its divergent light is reflected by the collimator mirror, producing a parallel light beam over the module.
3. During the flash illumination, current and voltage of the module are measured, together with the signal of a light sensor. This light sensor defines the irradiance level at every time, so it is identified the current and voltage point for the desired irradiance level, i.e. 850 W/m2.
4. This measurement is repeated at as many voltages of the IV curve as desired (5 or 6 points for a production line typically). The flash rate in our system is 4 seconds (time between flashes).
5. The IV curve is constructed with these points and the most important parameters are extracted: maximum power point, open-circuit voltage, short-circuit current, fill-factor and electrical efficiency.
Image credit: Cesar Dominguez |
