交直流混联配电网能够有效降低线路损耗、提高输电效率，是现代电力系统的重要发展方向。然而，交流与直流部分在故障特性上的差异、配电系统线路中存在大量的未能量测T接负荷，给保护的协调配合带来了严峻挑战。为解决上述问题，提出一种基于虚拟功 率变化量的新型保护方法。该方法应用特勒根定理分析含不同类别T接负荷下线路故障前后电气量的变化特征，计及各类T接负荷对故障特征量的影响提出了负荷占比估计技术，为故障特征修正提供理论依据，并利用修正后的功率变化暂态量实现交直流混联系统的精准保护。理论分析与仿真验证表明，该方法能准确识别故障，有效提升交直流保护的协同性与适应性，为混联配电网的安全稳定运行提供了可靠的保护解决方案。

AC/DC hybrid distribution networks can effectively reduce line losses and improve transmission efficiency, representing an important direction for modern power systems. However, the differences in fault characteristics between AC and DC sections, coupled with the presence of numerous unmetered tapped loads in distribution lines, pose significant challenges to the coordination and performance of protection schemes. To address these issues, this paper proposes a novel protection method based on power variation. By applying Tellegen’s theorem, the method analyzes the variation characteristics of electrical quantities before and after faults in lines with different types of tapped loads. Taking into account the influence of various tapped loads on fault indicators, a load proportion estimation technique is proposed, providing a theoretical basis for fault feature correction. Accurate protection of the AC/DC hybrid system is then achieved using the corrected transient power variation quantities. Theoretical analysis and simulation results demonstrate that the proposed method can accurately identify faults, effectively improve the coordination and adaptability of AC/DC protection, and provide a reliable protection solution for the safe and stable operation of hybrid distribution networks.