Rapid Shutdown with Panel Level Electronics-A suitable safety measure?

In the last years, requirements for a rapid shutdown of the PV generator at string level during an emergency came up. In order to comply with the new requirements, a variety of vendors entered the market with technical solutions. Contrary to intentions, an increase of serious emergency situations, even fires [1], had to be observed. The recent NEC 2017 [2] requires, amongst others, a rapid shutdown on module level. This tightens the situation because it leads to even more components in the PV system using Panel Level Electronics (PLE). Hence, this paper will discuss the harsh operating conditions and system failures that can occur within a PV plant and which directly affect the design of PLE.