6533b835fe1ef96bd129fd70
RESEARCH PRODUCT
Equivalent cell temperature calculation for PV modules with variable ideality factors
Tor Oskar SaetreOle-morten MidtgardGeorgi Hristov Yordanovsubject
Operating temperaturebusiness.industryControl theoryElectrical engineeringTemperature dropIec standardsbusinessTemperature measurementVoltageMathematicsdescription
Outdoor testing of PV modules involves monitoring their operating temperatures which have strong influence on the output power. Back-of-module sensing is associated with significant uncertainty due to temperature drop across the back encapsulation and also due to non-uniform temperature over the module's area. The international standard IEC 60904-5 defines a procedure for calculating the Equivalent Cell Temperature (ECT) of PV devices from their open-circuit voltage. This and other standards (as well as some module performance models) assume a single-exponential I-V curve model with a constant ideality factor. However, this parameter may vary with the illumination level and the operating temperature. If this variation is significant, the standard ECT calculation procedure may introduce unacceptable errors. A new equation is derived for the case when both dependencies are linear.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-06-01 | 2012 38th IEEE Photovoltaic Specialists Conference |