A Novel Transient Model of Photovoltaic Module Considering Electromagnetic Coupling

Photovoltaic (PV) arrays are threatened by lightning strikes due to the wide-open installation area. Lightning surges can not only damage the insulating structures of PV modules but also reduce the efficiency of a cell. Considering the electromagnetic coupling between the PV-cell string and the metal frame, a novel transient model of PV module is developed in this article. The proposed model is compared with the method of moments and validated by the previous experimental results. The effect of PV-cell wiring on lightning-induced voltage is comprehensively analyzed. The result indicates that the induced voltage of PV module is determined by the impulse magnetic field. The wiring scheme has a great impact on the induced voltage since it changes the area of the loop. The lightning overvoltage between the PV module and the bracket can be reduced by the use of an additional down conductor. The proposed model is more comprehensive and efficient than previous studies. It can be used to evaluate the induced voltage of PV module and predict the failure mode of the bypass diode caused by a lightning strike.