The pilot protection scheme based on Tellegen’s theorem for the outgoing line of photovoltaic station

The fault characteristics of photovoltaic power supply are obviously different from those of traditional power supply, which will lead to the decrease of traditional pilot protection performance. From the perspective of fault current of photovoltaic power supply, this paper analyzes that when the transmission line of photovoltaic system fails, the equivalent fault branch set before the failure is consistent with the topology of the line after the failure, which satisfies the relationship between voltage and current in Tellegen’s theorem. Based on this characteristic, a pilot protection for the transmission line of photovoltaic system based on Tellegen’s theorem is constructed. Finally, based on the PSCAD-EMTDC simulation platform, the simulation model of the photovoltaic power transmission system is established, and the influence of various factors such as different fault types and fault locations on the protection is considered. Finally, the simulation verifies that the protection has good operation performance.