I am trying to create a PAN File for a PV module where I don't know the IV curve at STC. My Gref and Tref in the "Definition of a PV module > Basic data" sheet are 800 W/m² and 45°C. In this case it seems that the "temperature correction on Gamma" tool does not work correctly. I will give you an example so that you will be able to reproduce my problem. I select "Tools>PV modules" and in "Choosing a PV module" I choose "50 Wp 25 V, Sipoly, CS 50, Centennial Solar, Photon Mag. 2009". In a first step I retreive the performance of this module at 800 W/m² and 45° from the "Definition of a PV module > Basic data > internal model result tool". I obtain Impp = 2.2 A, Isc = 2.42 A, Vmpp = 16.3 V, Voc = 20.2 V, Tc = 0.49 %/°C. Now I try to create a new PAN File for the CS 50 module based on this information. In "Definition of a PV module > Basic data > Manufacturer specifications or other Measurements" I enter Gref = 800 W/m², Tref = 45°C, muIsc = 1.2 mA/K, and the values for Impp, Isc, Vmpp, Voc. Then I go to the "Definition of a PV module > Model parameters > Temper. coeff" sheet and check that the temperature coefficient at STC is set to 0.43%/°C. The corresponding "Gamma temp. coeff" is 0.04 %/°C. If I go back to "Definition of a PV module > Basic data > Internal model result tool", I get 0.44 %/°C at 1000 W/m² and 25°C. First I suspected that this special set of one diode model parameters somehow resulted in a minimum temperature coefficient of 0.44 and smaller values could not be achieved. Therefore I tried putting 0.44%/°C in the "Definition of a PV module > Model parameters > Temper. coeff" sheet. I expected that the gamma temperature coefficient should not change and I would again get the 0.44 %/°C in the "Definition of a PV module > Basic data > Internal model result tool". However, this was not the case. For 0.44%/°C in the "Definition of a PV module > Model parameters > Temper. coeff" I get a "Gamma temp. coeff" of 0.07%/°C and a temperature coefficient of 0.45 %/°C at STC from the "Definition of a PV module > Basic data > Internal model result tool". Can you help? Thanks a lot in advance!
