This paper theoretically analyzes the current characteristics after a fault occurs in the transmission line of large-scale photovoltaic power generation
and proposes a large-scale photovoltaic transmission line pilot protection method based on the Hellinger distance. The current sampling values after the fault are discretized into probability distributions
and the similarity of the sampling value distribution on both sides is quantified using the Hellinger distance algorithm. The internal and external faults are judged based on the calculation results. The simulation verification shows that the proposed method can reliably respond to the internal and external faults of the protected line
and has good anti-noise and anti-synchronization error capabilities. Compared with the existing similarity protection and traditional pilot current differential protection
the proposed protection principle is more reliable.