交叉互联电缆行波故障测距的研究

Research on traveling wave based fault location for cross-bonded power cable

交叉互联电缆护层的交叉互联点和直接接地点行波波阻抗不连续,行波的折反射比较复杂,行波测距时无法识别出故障点的反射波和电缆对端反射波。通过分析电缆各个模量参数的特性,给出了电缆故障类型的判据,提出以电流模量4作为行波测距信号的行波测距算法,有效解决了行波在交叉互联电缆上折反射复杂给行波波头识别带来的干扰问题以及第二个反向行波的判别问题。在ATP-EMTP中建立220 k V电缆系统的仿真模型,仿真结果表明该测距算法可行性好,测距精度高。

As the wave impedance is significantly discontinuous at the sheath cross-bonded points of the cable,the reflection and refraction of traveling wave are extremely complicated,which makes it hard to identify the traveling wave reflection from the fault point or the end point of cable. By analyzing the characteristic of modal parameters,this paper offers the criterion of fault type judgment and proposes a novel fault location scheme by using the model four as fault location signal. The scheme solves the problem of wave front identification in traditional fault location methods due to the complicated reflection and refraction of traveling wave and also solves the problem of second reverse wave identification. A simulation model of 220 k V power cable system is built by ATP-EMTP,and the simulation results show that the fault location scheme is feasible and has higher accuracy.