Portable LED Flasher with Implemented Bypass Diode Tester

29th European Photovoltaic Solar Energy Conference and Exhibition; 2541-2545
A new LED based photovoltaic module flasher is presented to perform nominal power measurements at 1000W/m2 within a flash period of 10ms, together with low light measurements. Additionally performance tests of the typical 3 bypass diodes of a standard 6” crystalline silicon PV module are performed during three flasher periods within totally 2 seconds. Thus the flasher setup (2.2m x 1.5m x 0.1m, weight 50kg, including power electronics) is placed in a distance of a about five centimeters direct onto the PV module, which remains mounted in the same position as it is operated in the outdoor PV plant. The LED flasher is equipped with 2400 single blue LEDs and 1440 IR LEDs. The total flasher area is divided into twenty individually controlled subsections with an area of 0.13m2 each. During one flasher period different values of intensity and color composition are able to be controlled independently. Two LED colors are used at 455nm and 850nm. A standard crystalline module is typically divided in three sub-module areas, protected by one bypass diode for each sub-module. Thus the intensity of these three submodule areas relative to each other is varied. During a single flash up to four different intensity patterns are applied. The complete measurement system was successfully qualified by test sequences performed on standard modules, equipped with different defect bypass diodes. The fast method may also be applied as a new module end test in a production line as well as a new PV field test method performed within a few seconds by the mobile LED flasher.