Monitoring and Suppression of the Typical Hot-Spot Phenomenon Resulting From Low-Resistance Defects in a PV String

This paper presents a novel hybrid control method for the monitoring and suppression of the typical hot-spot phenomenon during power generation. It has been reported that such hot-spots generally result from low-resistance defects, and can influence the safe operation of photovoltaic generation system. In the present work, the formation of hot-spots via this mechanism is compared with the classical formation mechanism and a scan-based technique is proposed for hot-spot detection. This study demonstrates that periodic examination of the I-V curve can detect hot-spots and thus ensure safe operation to protect modules. This new method was validated by a series of experiments using a laboratory prototype and compared with the conventional perturbation and observation approach. The results show that this newly developed technique has the potential to allow the power generation system to operate safely.