Adaptability Analysis of Overcurrent Protection in Active Distribution Networks Under Extreme Conditions

Abstract

To address the failure of traditional protection caused by the high-proportion and multi-point dispersed integration of distributed generation (DG), this paper conducts an adaptability analysis of multi-stage protection in active distribution networks (ADNs) under extreme conditions. Based on the established short-circuit models for various types of DGs, this paper rigorously derives the extreme value of the shunting effect at the electrical midpoint of the fault circuit. Furthermore, the precise short-circuit current boundaries under the 100% penetration limit are explicitly determined: the maximum infeed current triggering sympathetic tripping reaches 14.84 kA, while the fault current drops to 0.87 kA under the extreme shunting scenario. These quantitative boundaries provide a theoretical benchmark for the optimization of distribution network protection configurations.