Uncertainty analysis for power rating measurement of photovoltaic modules

While determining power characteristic of PV modules, standart test conditions (1,000 W/m2 solar irradiance, 25°C temperature ve 1,5 AM) are always used. But, the real conditions may be different on site. Therefore, analyzing of a PV module's performance characteristics on different irradiance and temperature levels can give exact information about the quality of PV modules. The power rating measurements of PV modules under different irradiance intensity and temperature points may be verified according to IEC 61853 standard. Test results according to this international standard are also used for the efficiency calculation. Therefore, it's important to know which conditions effects the measurement uncertainty. The uncertainty calculation for power rating measurements under standard test conditions has already been analyzed detailly by accredited laboratories. For the other test conditions, the uncertainty is estimated roughly. At this thesis study, power rating tests are measured by AAA class solar simulator in 100-1,100 W/ m2 irradiance and 15-75°C temperature level. Additionaly, measurement characteristics (spectrum and stability of irradiance, irradiance intensity level and temperature homogeneity etc.) were analyzed for different irradiance intensity levels. Besides, hysteresis specifications of the different kind of silisium based PV modules were analyzed under these measurements. The detailed uncertainty measurement of the tests was calculated, too. According to these results, the parameters effecting the power rating measurements are analyzed.