基于回路直流电阻测量的输电线路单相接地故障离线故障定位

Fault Path Direct-Current Resistance Based Off-Line Single-Phase-To-Ground Fault Location

首先基于线路绝缘电阻测量进行故障检测和诊断——识别故障类型和故障相,然后针对发生率最高的单相接地故障,提出基于回路直流电阻测量的离线故障定位方法。定位前先对线路直流电阻和大地回路电阻进行测量,随后考虑接地电阻影响,分别利用故障相构建两回独立电压方程组,通过求解方程组计算故障距离。基于PSCAD/EMTDC搭建仿真模型进行验证,证明了方法正确性,同时将该方法在现场进行了应用,证明了方法的有效性,对于及时清除新建和大修线路的故障并保证线路的及时投运有重要作用。

In order to figure out the off-line transmission line fault location, a new fault location method based on fault path direct current resistance measurement is proposed. Firstly, an off-line fault detection and diagnosis method based on three-phase insulation resistance measurement is proposed, including fault type and fault phase diagnosis. Then the single-phase-to-ground fault location method is proposed which occurred the most frequently. In the proposed methods, the ground resistance and three phase directcurrent resistance between two substations are measured firstly. Then considering the effect of fault resistance, the KVL is used to form two independent equations which contain two unknown numbers, fault resistance and fault distance. Then fault distance and fault resistance can be figured out by solving equation set. The proposed method is verified in the PSCAD/EMTDC by simulation.The correctness and accuracy of the proposed fault location method are verified. Also it is verified in the field test. It is helpful for clearing the fault for newly-built lines and overhaul lines. It is very important to ensure that transmission lines are put into operation on time.