近年来，为应对日益严峻的能源危机和环境污染问题，我国提出了“双高”电网的建设目标，分布式电源(Disributed Generator, DG)在配电网中的渗透率日益提升。其中，逆变型分布式电源(Inverter Interfaced Distributed Generators, IIDG)是DG并网的主要形式。IIDG的接入改变了配电网的潮流流向和短路电流分布，使其转变为多电源共同作用的有源配电网，保护难度进一步增加。为此，本文对故障暂态特征进行了深入研究，提出了一种基于瞬时正序实部电流特征的有源配电网纵联保护方法。具体研究工作如下：

（1）建立了有源配电网瞬时正序实部网络模型，并进行了故障暂态特征研究。利用瞬时对称变换对有源配电网中各元件进行分析，进而建立了有源配电网瞬时正序实部网络模型。选取瞬时正序实部电流分量作为特征量，并求解网络模型方程进行暂态特征研究。结果表明：当故障发生时，各检测位置的瞬时正序实部电流分量存在突变点，且故障线路首末两端的暂态信号由于组成不同所以在波形上存在差异。故障特征的研究为后续建立有源配电网保护方法奠定了基础。

（2）提出了基于Teager能量算子的启动判据。判据利用Teager能量算子辨识瞬时正序实部电流突变点，进而构造启动判据，并确定故障时刻。解决了电流突变量判据无法满足启动要求的问题。通过Matlab/Simulink建立的有源配电网仿真模型，验证了所提启动判据的有效性。

（3）提出了基于古德曼相关性系数的保护判据，并构建了纵联保护方法。利用古德曼相关性系数辨识线路首末两端暂态电流信号相似度，构造保护判据。基于启动判据和保护判据，本文建立了有源配电网纵联保护方法，该方法充分利用暂态波形特征，提高了保护的可靠性和速动性。利用仿真模型及实验室有源配电网物理实验系统对本文保护方法进行仿真分析和实验验证。结果表明，所提方法在不同故障条件下均能准确判断故障进行保护。

In recent years, in response to the increasingly severe energy crisis and environmental pollution issues, China has proposed the construction goal of "dual high" power grids, and the penetration rate of distributed generators (DG) in the distribution network is increasing. Among them, Inverter Interface Distributed Generators (IIDG) is the main form of DG grid connection. The integration of IIDG has changed the flow direction and short-circuit current distribution of the distribution network, transforming it into an active distribution network with multiple power sources working together, further increasing the difficulty of protection. Therefore, this thesis conducts in-depth research on the transient characteristics of faults and proposes a pilot protection method for active distribution networks based on current waveform characteristics. The specific research work is as follows:

(1) An instantaneous positive sequence real part network model for active distribution networks is established and transient fault characteristics is also carried out. This thesis uses instantaneous symmetry transformation to equivalent various components in active distribution networks, and then establishes an instantaneous positive sequence real part network model for active distribution networks. Select the instantaneous positive sequence real part current component as the characteristic quantity, and solve the network model equation for transient characteristic research. The results show that when a fault occurs, there are sudden changes in the instantaneous positive sequence real part current components at each detection position, and the transient current signals at the beginning and end of the line after the fault have differences in waveform due to their different compositions. The study of fault characteristics lays the foundation for the subsequent establishment of active distribution network protection methods.

(2) A starting criterion based on Teager energy operator was proposed. The criterion uses the Teager energy operator to identify the sudden change point of the instantaneous positive sequence real part current, and then constructs a starting criterion and determines the fault time. Solved the problem that the criterion for sudden current changes cannot meet the starting requirements. The effectiveness of the proposed starting criterion was verified through the simulation model of active distribution network established by Matlab/Simulink.

(3) A protection criterion based on Goodman correlation coefficient has been proposed. By using the Goodman correlation coefficient to identify the similarity of transient current signals at the beginning and end of the line, a protection criterion is constructed to achieve accurate fault identification. Use simulation models and laboratory active distribution network physical experimental systems to conduct simulation analysis and experimental verification of the protection method proposed in this paper. The results indicate that the method proposed in this paper can accurately identify faults for protection under different fault conditions.

(4) Based on the starting criterion and protection criterion, this paper establishes a pilot protection method for active distribution networks, which fully utilizes the characteristics of transient waveforms and improves the reliability and speed of protection. At the same time, this thesis also provides implementation methods for protection, further improving the methods proposed in this thesis.