基于冲击响应特性的10kV电缆网络缺陷定位方法

A new method of defect location for 10 kV cable networks based on impulse response characteristics

为了在10 k V电缆网络中确定缺陷的位置,提出了一种根据电缆在冲击电压下的不同响应特征对电缆进行绝缘诊断的新方法。在PSCAD/EMTDC中建立了工频叠加冲击电压下10 k V电缆网络仿真模型,分析了电流、电压在主电缆馈线上的暂态传播特性,利用电流变化表征电缆缺陷,判断缺陷位置。通过传播特性仿真发现,在冲击源的两侧电流呈双极性,而电压呈单极性。在仿真中设置电缆缺陷,发现了测试电缆段两侧的电流在有缺陷和无缺陷的情况下有明显区别。通过对比电缆在出现缺陷前后主馈线各节点的电流波形变化,能够判断电缆缺陷所在的位置。

To investigate the defect location of the 10 k V cable network,a novel method of insulation diagnosis based on different response characteristics of cable under impulse voltage is presented. Simulation model of 10 k V cable network under power frequency voltage superimposed of impulse voltage is constructed in PSCAD / EMTDC program. The transient propagation characteristics of the current and voltage on the main cable feeder are analyzed. The change of the current is used to present the defect of the cable and judge the location of the defect. The simulation results of propagation characteristics show that the current on the two sides of the impulse source is bipolar,while the voltage is single polar. After the defect is set in a cable,the current on the two sides of the test cable is different from the current before the defect is set. Comparing the change of the current waveform of each node on the main feeder with and without defect,the location of the defect can be estimated.