Abstract-This paper focuses on fault evolution in a photovoltaic array during night-to-day transition. The effect of a maximum power point tracker on fault current is first discussed. When a PV fault occurs in daylight, overcurrent protection devices work properly. However, when the same fault occurs at night, our results demonstrate that the fault current is difficult to detect. As a result, the fault might be hidden in the PV array and become a potential hazard for system efficiency and reliability
