Adaptive Sampled Value Differential Protection With High Penetration of Inverter-Based Resource Based on Error Function Fitting

As power systems continue to evolve and modernize, the integration level of renewable energy sources in distribution grids has been steadily increasing. Traditional protection schemes in distribution grids, such as directional current protection, are influenced by the fault characteristics of inverters, posing challenges such as fault current limiting and frequency deviation. Moreover, the conventional phasor-based protection principles struggle to accurately characterize non-fundamental frequency fault currents. While Sampled Value Differential Protection (SVD) overcomes these limitations, it remains vulnerable to measurement errors under low-current conditions, compounded by the absence of industry standards for error handling. This issue leads to a lack of foundation for setting of SVD and hinders quantitative operation, maintenance, and testing. To address these gaps, this paper introduced an adaptive sampled value differential protection (ASVD) scheme. The proposed method utilized pre-fault steady-state current for time-domain error estimation, establishing a floating threshold to dynamically adjust protection characteristics. The effectiveness and reliability of this scheme were successfully verified through simulations. Compared to conventional differential protection methods, the ASVD scheme demonstrates adaptability, sensitivity and reliability to different operating conditions of high penetration inverter-based resource (HPIB). This promising approach provides a new solution to address the practical engineering challenges posed by the high integration of inverter-based resource into distribution grids.