基于暂态电压比初始值和时域迭代的直流配电网单端测距方法

针对直流配电网线路单端故障测距精度不高的问题，提出了一种基于暂态电压比的单端故障测距方法。该方法通过分析故障发生后限流电抗器两端故障电气量的特征和数学表达式，构建了时域内基于限流电抗器两端暂态电压比的故障测距方案，并利用迭代的方法削弱过渡电阻对故障测距精度的影响。该方法利用单端电气量，耐过渡电阻能力强，对通信无严格要求，无需安装同步装置，提高了直流配电网线路单端故障测距的精度。在PSCAD/EMTDC平台搭建多端直流配电网模型，对所提测距方法进行仿真分析，结果证明所提方法可以实现基于单端电气量的精确故障测距。

Single-terminal fault location method in DC distribution network based on initial ratio of transient voltage and time-domain iteration

Aiming at the problem of low accuracy of single-terminal fault location in DC distribution network, a single-terminal fault location method based on transient voltage ratio is proposed. By analyzing the characteristics and mathematical expressions of the fault capacitance at both terminals of the current-limiting reactor, a fault location scheme based on the transient voltage ratio at both terminals of the current-limiting reactor is constructed in the time domain, and the influence of the transition resistance on the fault locating accuracy is reduced by an iterative method. The method uses single-terminal electrical quantities. It has strong resistance to transition resistance without strict requirements on communication, and does not need to install synchronization device, thus improving the accuracy of single-terminal fault location of DC distribution network lines. The multi-terminal DC distribution network model is built on the PSCAD/EMTDC platform, and the simulation analysis of the proposed location method is carried out. The results show that the proposed method can achieve accurate fault location based on single-terminal electrical quantities.