Fault Characteristics of Schottky Barrier Diode used as Bypass Diode in Photovoltaic Module against Repetitive Surges

Abstract

In recent years, there has been an increasing number of cases involving damage to photovoltaic systems (PVS) due to lightning strikes. In a PVS that has been damaged by lightning, a protective device inside the photovoltaic module (PV module), i.e., the bypass diode (BPD), fails, thus leading to fire. Presently, the Schottky barrier diode (SBD), made of silicon, with a low reverse withstand voltage is widely used for BPD in PV modules; therefore, damage from lightning is a concern. In this study, a lightning surge test on an SBD that mimics a case where the SBD is used as the BPD in the PV module that receives the repetitive lightning surges is performed. The test result showed that when repetitive lightning surges were repeatedly applied, regardless of forward or reverse application to diodes, increasing the number of applications reduced the fault resistance.