# Optimization of Distribution Network Current Protection for Inverter-Based Distributed Power Access
## 7 Conclusions  
This paper aims to provide insight into the impact of inverter-based distributed generation (IIDG) access on current Protections II and III in the upstream stage of the distribution network through simulation analysis. To this end, a distribution network model incorporating IIDGs has been constructed, enabling a comparison of the sensitivity of upstream protection at varying IIDG output levels. The findings indicate that IIDG access does indeed reduce the overcurrent sensitivity of upstream protection, which, in turn, affects the effectiveness of current Protections II and III. The findings of this study substantiate the hypothesis that the integration of IIDGs into the distribution network results in a reduction in the sensitivity of the upstream protection devices, which is attributable to their impact on fault currents. This finding is consistent with the existing literature on the impact of distributed generation on distribution network protection. The increase in the output power of the IIDG results in a decrease in the current detected by the upstream protection device during faults, which, in turn, affects the sensitivity and response time of the protection device. To solve this problem, this paper proposes an innovative approach to dynamically adjust the protection values according to the changes in the load current. The core of this method is to use real-time data to optimize the protection settings to adapt to the changes in the IIDG output, thus improving the sensitivity and selectivity of the protection system. Simulation results show that the method can effectively improve the response sensitivity of the fast disconnection protection in the Current II section and the fixed-time overcurrent protection in the Current III section, thus improving the current protection capability of urban distribution networks. The key advantage of the methodology employed in this study is its capacity to adapt to fluctuations in IIDG outputs without necessitating extensive modifications to existing protection devices. The implementation of this method not only enhances the sensitivity of the protection system but also preserves the stability and selectivity of the protection, which is crucial to guarantee the reliability and security of the distribution network. While this study offers valuable insights, future research should aim to further enhance the theoretical analyses in order to explore the range of current protection under different IIDG outputs. Furthermore, the construction of more accurate IIDG models and the consideration of transient processes during fault occurrence will facilitate the validation of the proposed scheme in practice. Future work will also investigate the applicability of the method in diverse types of distribution networks and under varying operational conditions, as well as its integration with other sophisticated protection techniques. In conclusion, this study not only demonstrates the influence of IIDG access on distribution network current protection but also presents a practical solution for protection optimization in distribution networks, namely, a novel protection value adjustment method. It is anticipated that as distributed generation resources gain in popularity, the findings and methods presented here will have a significant impact on the stable operation of distribution networks and the development of protection strategies. Conceptualization, C.X. and Q.C. ; Methodology, Q.C. ; Software, Y.R. ; Verification, Y.R., C.X. and Q.C. ; Formal analysis, C.X. ; Investigation, C.X. ; Resources, C.X. ; Data management, X.H. ; Writing--First draft preparation, X.H. ; Writing--Review and Editing, X.H. ; Visualization, X.H. ; Supervision, X.H. ; Project management, X.H. ; Funding acquisition, X.H. All authors have read and agreed to the published version of the manuscript.