Arc Extinguishing in Photovoltaic Systems

In last years, the number of photovoltaic systems installed worldwide has increased. The safety and quality standards have been further developed and today offer a high degree of safety and reliability.

In this context, potential weaknesses in the system are analyzed. A current topic in this context is the short circuit in photovoltaic systems. In DC circuits the arc is stable due to the lack of periodic zero crossing. Appropriate measures must be taken for plant and personal protection. An arc detection system with a DC shut-off element is favored as a solution approach. The idea of the arc detector between the inverter and the solar panels in the DC circuit is based on the fact that the occurrence of a short circuit results in significant changes in the frequency response of the current, which are analyzed and detected by electronic evaluation logic.

This gives then an instruction to the upstream protective element, e.g. DC load break switch with electronic tripping function, which then switches off the PV system and thus clears the arc. With the RESYS AFD arc detection system and the DC load breaker series up to 1500V DC and 1250A DC INOSYS LBS Socomec offers a corresponding solution portfolio (also UL-certified).