The traditional pilot protection relies on the fault characteristic quantities and high-precision line model establishment and is seriously affected by integrating new energy sources and distribution parameters. To address the above issues

this paper proposes a novel approach based on the virtual twin

simplifying the physical line model within a virtual space using a digital equivalent model. Then

a virtual fault equivalent model is derived. After that

the recursive least squares method is used to generate the normal digital model of the line

and the state space equations are established for the real-time state estimation

which is combined with the change of the state quantities and the virtual fault equivalence model for the situational awareness of the physical line. The proposed protection decouples the protected line from the outside world

and adopts the digital model as the equivalent representation of different kinds of line mechanism models in the virtual space

which is not affected by the power supply characteristics at the ports

system oscillations

communication delay

etc.

and does not depend on the actual line parameters

and applies to a wide range of physical scenarios. Finally

the correctness and effectiveness of the proposed protection are verified in extra-high-voltage trans-frequency line model sending system and a large-scale new energy sending system in PSCAD/ EMTDC. The fault identification time was within 10 ms

with a maximum tolerance of 1000 fault resistance

an average error of 4%

a maximum error of 8.34%

and a minimum error of 0.08%.