Explanatory Review about Rapid Shutdown Systems and Standards to Increase Safety in Photovoltaic Systems

Photovoltaic (PV) systems have been extensively used to provide clean energy from small-size solar roof applications to large-size power systems. Although its static conversion-based technology reduces most safety problems related to fatigue, there still some risks inherent to technology. One of these risks are parallel arc faults on dc side that generally occur due to poor installation of external source of fire. During daylight times, these faults cannot be extinct switching off ac circuit breakers since the sun continuously feed the arc by dc side. So, these faults bring high risks for people who live in buildings with PV systems, as well as for firefighters trying to extinguish them. Due this, in last years have been proposed many solutions to mitigate this problem, in special the rapid shutdowns systems. This paper presents an explanatory review of standards, technical data, and papers related to rapid shutdowns systems for PV applications. It is presented of the main existing solutions that can considered for further development of Brazil regulation.