Reference phasor correction-based fault self-synchronization for power grid protection

Abstract

The proliferation of distributed energy resources intensifies synchronization demands for distribution network differential protection, where conventional fault self-synchronization methods face accuracy limitations due to fault detection delays and channel uncertainties. To resolve this, we propose a reference phasor correction-based self-synchronization method. After the protection device is activated, this method utilizes a reference phasor at a specific pre-fault moment to correct errors in the traditional fault self-synchronization method. This approach is unaffected by fault detection delays and channel latencies, allowing it to achieve data synchronization that meets the requirements of differential protection in distribution networks without dedicated protection channels or external timing signals. The simulation results indicate that this method can achieve the synchronization accuracy required for feeder differential protection in various types of feeders. It remains unaffected by the initial fault phase angle and device sampling frequency, while exhibiting strong noise immunity. The method maintains high synchronization accuracy even when T-connected loads or distributed generation of certain capacities exist within the feeder, demonstrating robust noise resistance capabilities.