Re-looking the Shunt-Resistance Calculating Methodologies of IV-curves

This paper presents the shortcomings in existing methodologies used for calculating the shunt resistance from the current vs. voltage (IV) curves collected at the indoor lab under controlled conditions or the outdoor under natural conditions. This paper mainly presents the inverse slope methodology and shortcomings surrounding it. Shunt resistance is one of the critical parameters for detecting the low power faults like cracks in the modules caused by extreme conditions. The findings were validated on the IV curves of a PV module from indoor tests and a string from outdoor tests collected at stable conditions. The findings of this paper open a new window of opportunity to search for new calculation methodologies.