一种利用故障暂态过程的柔性直流配电网故障测距方法

A Fault Location Method for Flexible DC Distribution Network Based on Fault Transient Process

直流配电网的故障测距技术是保证其安全可靠运行的关键技术,为实现直流配电网保护装置动作后快速准确地确定故障位置,研究其故障测距技术十分必要。在总结现有交流电网以及高压直流输电网中故障测距方法的基础上,提出了一种利用直流侧电容暂态放电过程的柔性直流配电网故障测距的新方法。该方法从直流网络发生短路的暂态过程出发,将短路故障的暂态过程分段,提取其中电容放电的暂态过程来进行故障测距。首先在PSCAD/EMTDC中搭建了双端柔性直流配电网的拓扑模型;其次利用MATLAB对文中提出的故障测距算法进行仿真,验证其可行性和有效性;最后,提出对直流配电网故障测距算法评价的3个指标,并从此指标入手,将所提方法与其他适用于直流配电网的故障测距方法进行对比验证。

Fault location of flexible DC grid is one of crucial techniques for safe and reliable operation of power systems. It is necessary to discuss fault location technology to determine fault position quickly and accurately after action of protective devices of DC distribution network. This paper summarized current fault location methods applying on traditional distribution network and HVDC system, and proposed an improved method based on transient characteristics of capacitor discharging process. This paper also built a two terminal LVDC system based on PSCAD/EMTDC and performed simulation tests on the model to verify effectiveness of the method. Finally, based on test result, this method was compared with other fault location methods to reveal its advantages.