Longitudinal Protection of DFIG Feeder Line Based on Transient Current Phase Difference

As doubly fed induction generator(DFIG) has special control and low voltage ride-through strategy, which leads to the traditional industrial frequency quantity protection on its sending line will have certain unadaptability. There are more literatures about this proposed waveform synchronization protection based on the full amount of time-domain characteristics, but there are also problems such as possible delayed misjudgment, long data window time and so on. As a result, this paper proposes a longitudinal protection scheme for DFIG feeder line based on transient current phase difference. The scheme fully exploits the transient characteristics of the fault current, and utilizes the Hilbert transform, which is not affected by the complex components, effectively extracting the transient phase values of the currents at both ends of the line. The principle is simple, less affected by the transmission delay and the required data time window is short. Ultimately, the effectiveness of the suggested safeguarding approach is confirmed through the simulated test environment. The outcomes demonstrate that the new protective system functions effectively and can be depended upon across various fault scenarios.