This article investigates active distribution networks with distributed photovoltaic (PV) integration. Analyzing the specific control strategies of distributed PV units
the study characterizes the fault current magnitude and phase characteristics under varying PV output conditions. On this basis
it analyzes the operating range of the phase difference of the positive-sequence fault component of the current at both ends of the faulted line and concludes that the traditional current phase comparison type pilot protection may fail when the photovoltaic output is small. Therefore
this paper improves the criterion by combining the amplitude ratio and phase angle difference of the positive-sequence fault-component current and proposes an active distribution network pilot protection scheme based on comprehensive phase angle difference. This solution only needs to collect current information and does not need to install voltage transformers
making it highly economical. The simulation results show that this solution is not affected by variations in PV output or fault types.
WONG J Y R, TAN C, ABU BAKAR A H, et al. Selectivity problem in adaptive overcurrent protection for microgrid with inverter-based distributed generators (IBDG): theoretical investigation and HIL verification[J]. IEEE transactions on power delivery, 2022, 37(4): 3313-3324.
ZHENG X D, CHAO C X, WENG Y, et al.High-frequency fault analysis-based pilot protection scheme for a distribution network with high photovoltaic penetration[J]. IEEE transactions on smart grid, 2023, 14(1): 302-314.
YUAN T, GAO H L, PENG F, et al.Adaptive quasi-power differential protection scheme for active distribution networks[J]. IEEE transactions on smart grid, 2024, 15(1): 324-339.
XU S X, LU Y P, CHEN Y R.A novel current amplitude protection method for distributed generating system based on sufficient criterion theory[C]//2015 International Conference on Clean Electrical Power (ICCEP). Taormina, Italy, 2015: 800-805.